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Fabrication and Erection of Process Piping

 

Section Title Page
     
Purpose 2  
Scope 2  
Codes and Standards 2  
Related Documents 2  
Definitions 3  
General 4  
Material Control, Certification, and Traceability 4  
Welding 5  
Brazing and Soldering 8  
Shop Prefabrication of Piping Spools 9  
Cleaning of Pipe and Associated Systems 10  
Assembly 11  
Field Erection 13  
Repair and Replacement of Existing Work 13  
Weld Examination and Inspection 16  
Punchlisting 16  
Pressure Testing 16  
Painting 16  
Change Log 18  
       
Minimum Requirements for Radiography 15  
Process Safety Management (PSM) Documents 17  
Table of the Recommendable Temperatures for Consumable Storage, Drying, and Drying Maintenance 35  
       
Nondestructive Examination (NDE) Logic Diagram 21  
Electrode Distribution Control Form 34  
Electrode Handling Control Form (Reduced Form) 36  
       
HyCO Project Piping 19  
Requirements of the European Pressure Equipment Directive 26  
Recommended Weld Filler Material, Consumables Control and Handling 29  
Aluminium Welding 37  
       
       

 

1.         PURPOSE

 

1.1       This fabrication and erection specification, with the requirements contained in the relevant purchase order, defines the requirements for prefabrication, erection, cleaning, examination, inspection, and testing of piping systems. It shall apply to the supplier of prefabricated piping and piping skids and the contractor for field installation of piping systems.

 

 

2.         SCOPE

 

2.1       This specification applies to projects designed and constructed by or for Air Products. This specification shall be used in conjunction with the project-specific requirements specified in Project Specific Scope of Work.

 

2.2       This specification applies to all shop-prefabricated piping and piping skids, site-fabricated piping, and site-erected piping within the facility battery limits except:

 

  • Work performed in an Air Products manufacturing facility according to the requirements of the Cryogenic Systems–Vessel Design Group or work specified in accordance with 4ACB-680001.
  • Underground utility piping
  • Power boiler piping within boiler code jurisdiction limits (to be fabricated, inspected, and stamped according to ASME BPVC Section 1 or other internationally recognized boiler code).

 

2.3       The supplier shall furnish all materials, labor, services, tools, consumables and equipment required to fabricate, exam, clean, inspect, and prepare for shipment prefabricated piping according to the contract drawings and these specifications. The supplier shall furnish all materials except those specifically indicated as furnished by Air Products in the Project Specific Scope of Work.

 

 

3.         CODES AND STANDARDS

 

3.1       The supplier or contractor shall ensure that the piping conforms to the requirements of all codes (latest edition), standards, and specifications listed in this specification and any municipal, provincial, and national regulations in the country of use.

 

3.2       Fabrication and inspection of piping shall be according to ASME Code for Pressure Piping B31.3 unless specified otherwise in the Project Specific Scope of Work.

 

3.2.1   Piping may be designed and constructed in accordance with piping codes that are acceptable in the country of use if specified or approved in writing by Air Products. The supplier shall state in the bid documents the code to be used and shall be subject to purchaser’s approval.

 

3.3       When site-prefabricated piping and site-erected piping are intended for use on sites located in countries that are members of the European Economic Community (EEC), all work must comply with the requirements of the European Pressure Equipment Directive 97/23/EC. These requirements are summarized in Appendix B of this specification.

 

3.4       Any conflict between the requirements of this specification and other standards or codes shall be referred to purchaser for clarification and resolution before quotation.

 

4.         Related documents

 

            Note:  The documents listed in this section, by reference, form a part of this specification and refer to the latest edition and addenda in effect at date of contract award of any item covered by this specification. Any conflicts between the referenced documents not resolved by this specification shall be brought to the immediate attention of Air Products.

 

4.1       Air Products Engineering Documents

 

3PI55005               Pipe Thread Sealants Service Index

4ACB-680001         Cold Box Shop or Field Fabrication

4WCE-600001        General Scope of Work for Construction Contracts

4WCE-607001        Removal Procedure for Welded Shipping/Test Closures – Balloon Method

4WEQ-1105            HYCO Plant Positive Material Identification (PMI) Requirements

4WEQ-1120            ASU Plant Positive Material Identification (PMI) Requirements

4WEQ-6804            Painting and Corrosion Protection of New Construction for Design Temperatures to 649°C (1200°F)

4WPI-AWS002        Construction of Site Pipe Supports (Type SSW) and Field-Supported Piping

4WPI-EW44001      Pressure Testing of Process Piping and Equipment

            4WPI-FWZC01        Specification for Welded Temporary Pipe Closures

4WPI-FWZM01        Field Installation of Metallic Expansion Joints and Flexible Hoses

4WPI-FWZM02        Instructions for Field Installation of Mechanical Flexible Couplings

4WPI-FWZM03        Field Installation of Pipe Supports Welded to Operating Piping

4WPI-SW70001      Standard Clean (Class SC) Inspection and Acceptance Requirements

4WPI-SW70002      Process Clean (Class B) Inspection and Acceptance Requirements

4WPI-SW70003      Oxygen Clean (Class AA) Inspection and Acceptance Requirements

4WPI-SW70004      Fluorine Clean (Class AAAA) Inspection and Acceptance Requirements

4WPI-SW70006      Cleaning of Piping and Inline Equipment

4WPI-670210         Bolt-Up Procedure for Flanged Connections

 

4.2       The American Society of Mechanical Engineers (ASME)

 

Boiler and Pressure Vessel Code (BPVC)

Section V         Nondestructive Examination

Section VIII-1  Rules For Construction Of Pressure Vessels

Section IX        Qualification Standard For Welding And Brazing Procedures

B31.3               Process Piping

P-3A                 Engineer-Contractor Data Report for a Complete Boilers Unit

P-4A                 Manufacturer’s Data Report for Fabricated Piping

SFA 5.8            Specification For Filler Metals For Brazing And Braze Welding

SFA 5.10          Specification For Bare Aluminum And Aluminum-Alloy Welding Electrodes And Rods

 

4.3       British Standard Euronorms

 

BS EN 10204          Metallic products: Types of inspection documents

 

4.4       European Council/Commission Legislative Documents

 

97/23/EC                Directive of the European Parliament and the Council on the Approximation of the Laws of the Member States Concerning Pressure Equipment

 

4.5       CEN – European Committee for Standardization

 

EN 1252           Cryogenic Vessels – Materials

CEN-EN-ISO-15614-1   Specification and Qualification of Welding Procedures for Metallic Materials Part 1: Arc and Gas Welding of Steels and Arc Welding of Nickel and Nickel Alloys

EN 13480         Metallic Industrial Piping

 

 

  1. DEFINITIONS

 

5.1       Definitions shall be as defined in 4WCE-600001 unless modified as follows:

 

5.1.1   Supplier shall mean the company awarded the supply of prefabricated piping if different than the contractor for field installation.

5.1.2      Purchaser representative shall mean the designated representative of purchaser in charge of the work at the site or elsewhere and whose name has been notified as such to the contractor. This representative has been delegated the responsibilities of the “owners inspector” in the terms of ASME B31.3.

 

5.1.3      CE mark shall mean the mark applied to pressure equipment that conforms to the requirements of the European Union Pressure Equipment Directive (97/23/EC).

 

 

  1. GENERAL

 

6.1          Scope of prefabrication shall be at the discretion and responsibility of the supplier and/or contractor. The supplier and/or contractor shall be responsible for the selection of field welds to suit transportation, constructability, and spool cleaning.

 

6.1.1      Substantial changes to the as-bid ratio of shop-to-field welding arising from the selection of field welds shall be highlighted to the purchaser in writing. Without prior written acceptance, the purchaser will not accept any additional costs for such a change.

 

6.1.2      Purchaser may specify the location of field welds. If the supplier and/or contractor wants to change the location of such field welds, they shall advise the purchaser for approval before making changes. This shall be done by marking up a set of piping isometric drawings and returning them to the purchaser. Supplier/contractor shall allow a two week review period without claim for schedule delay.

 

6.2          Pipework constructed to oxygen cleanliness standards shall be spooled for prefabrication so that the line can be adequately visually inspected along its whole length. This requirement might limit the degree of prefabrication possible (no more than two bends) and shall be allowed for by the contractor.

 

6.3          The contractor shall ensure segregation of dissimilar materials of pipework during storage and fabrication.

 

6.4          The cost of all rework resulting from a failure on the supplier and/or contractor’s part shall be borne by them.

 

 

  1. MATERIAL CONTROL, CERTIFICATION, TRACEABILITY

 

7.1          Material Control

 

7.1.1      The contractor shall receive all ‘free issue’ equipment and materials that have been supplied by the purchaser, offload, and store as required according to 4WCE-600001.

 

7.1.2      The contractor shall operate a controlled site welding consumable store and shall develop and implement a procedure to assure the correct weld rod and weld procedure is used. Any costs incurred through the need for material identification (PMI) caused by the contractor’s failure to demonstrate adequate weld rod control shall be to contractor’s account. Refer to Appendix C for additional information.

 

7.2          Certification

 

7.2.1      Refer to 4WCE-600001 for details.

 

7.3          Traceability

 

7.3.1      The contractor shall ensure that the degree of traceability of all materials is according to the requirements stated in the project documents and applicable codes.

 

7.3.2      Material traceability is required, and a material map shall be prepared by the contractor using the isometric drawings, showing the material heat or cast number for each component of the system. The material certificates relating to each isometric shall be included with that isometric in the final system dossiers. The contractor shall assume that all national authority regulated lines require full material traceability.

 

7.3.3      Refer to Appendix B of this specification for European Pressure Equipment Directive (PED) material traceability requirements.

 

7.4          Positive Material Identification (PMI) Requirements

 

7.4.1      The contractor shall ensure that Positive Material Identification (PMI) is performed on all piping systems in accordance with Air Products Specification 4WEQ-1105 or 4WEQ-1120.

 

 

  1. WELDING

 

8.1          General Welding Requirements

 

8.1.1      Nomenclature Used in Welding Sections

 

               FCAW             Flux Cored Welding

GMAW           Gas Metal Arc Welding (MIG)

GTAW            Gas Tungsten Arc Welding (TIG)

SMAW            Shielded Metal Arc Welding (Coated Electrode/Stick)

 

8.1.2      At least one pass per 3 mm (1/8 in) of wall thickness shall be made.

 

8.1.3      Downhill welding process is prohibited.

 

8.1.4      Slag shall be removed before depositing succeeding layers.

 

8.1.5      Peening to cover weld defects shall not be allowed.

 

8.1.6      Welding by creating a heat pattern at a circumferential joint can “draw in” the weld and the base metal in the heat-affected zone, thereby creating a “belling in” and giving a reduction in the area of the pipe or tube. This belling or distortion is undesirable and is subject to the following limitations:

8.1.6.1   The belling or distortion tolerance may not exceed 1% of the actual outside diameter (OD) or 1.5 mm (1/16 in); whichever is larger. This belling or distortion can be measured by comparing the actual OD at the belled or distorted area.

 

8.1.7      All slip-on flanges shall be welded internally and externally. Internal welding of utility piping may be deleted, and will be specified as such, in project specific documents or drawings.

 

8.1.8      When backing rings are permitted, they shall be cut by the contractor from piping material matching the P number of the pipe base metal composition.

 

8.1.9      When attachment welds are of a temporary nature, they shall be either mechanically or thermally cut at least 3 mm (1/8 in) from the final surface and ground flush. The “knocking-off” of temporary attachments is strictly forbidden.

 

8.2          Qualifications Required for Welding Procedures and Welders

 

8.2.1      All pipe welding, including attachment welds to piping, shall be performed according to qualified procedures developed by the contractor or supplier and by welders qualified to the procedures in accordance with ASME BPVC Section IX and as modified by ASME B31.3, section 328.2 (see also sections 8.6 and 8.7).

 

8.2.2      A minimum of fourteen calendar days before welding the contractor shall submit to the purchaser’s representative two copies of all Welding Procedure Specifications (WPS) and weld Procedure Qualification Records (PQR) to be used on the project for approval. No welding shall be performed until approved in writing by the purchaser.

 

8.2.3      The welder qualification shall be submitted to the purchaser’s representative a minimum of two days before the start of welding.

 

8.2.4      All costs of qualifications shall be borne by the contractor or supplier.

 

8.3          Filler Material

 

8.3.1      See Appendix C or Appendix D.

 

8.4          Weld-joint Preparation

 

8.4.1      The contractor or supplier shall prepare all welding joints according to the specified code and the approved WPS.

 

8.4.2      Stainless steel pipe shall only be cut by mechanical or plasma cutter processes. A minimum of 1.0 mm (0.04 in) shall be removed from the pipe by grinding to eliminate any trace of carbon that may have been deposited by plasma cutting.

 

8.4.3      When oxy-fuel or plasma cutting is used for carbon and low-alloy steel, the same preheat defined by the WPS for the material shall be performed before the start of any cutting. The resulting surface shall be ground back to bright metal before welding.

 

8.4.4      Weld bevel preparation for steels containing greater than 2% chromium content shall be machined or ground back by at least 1.6 mm (1/16 in) to clean sound metal if the initial preparation was made using thermal cutting techniques.

 

8.4.5      Materials that are being welded shall be carefully fit, aligned, and retained in position during the welding operation. Adequate and proper tack welding will be considered acceptable. Tacks shall not obstruct a full-penetration weld. Before starting to weld, tacks must be thoroughly cleaned.

 

8.4.6      The inside surfaces of piping components to be joined by butt welding shall be aligned so that the misalignment at any point on the inside circumference does not exceed 1.5 mm (1/16 in) or 1/4 of the nominal thickness of the component with the thinner wall, whichever is smaller.

 

8.4.7      Branch connections shall not intersect the longitudinal seam of welded pipe.

 

8.4.8      The contractor shall ensure that the seams of any prefabricated piping spools do not coincide with the seams in fabricated miters.

 

8.4.9      Material provided for the fabrication of miters, pipe fittings, or pipe shall not be provided with any weld preparation unless specifically advised by the purchaser. The contractor shall allow for making the required weld preparation.

 

8.5          Material Specific Welding Requirements

 

8.5.1      Welding Requirements for Carbon Steel, Chrome-moly, Stainless Steel, and Monel

 

8.5.1.1   The contractor shall perform all welding according to the applicable code. The following welding processes are permitted for making one-sided groove welds:

 

Stainless steel, Monel, and Inconel welded to each other or to carbon steel:  GTAW shall be used for all weld passes on schedule 5 and 10 piping. For heavier piping, the root bead shall be made with GTAW; the balance of the weld may be made using another Air Products-approved welding process. All welding shall be made using an internal gas purge of either argon or nitrogen gas. The use of backing rings is not permitted except for final closure welds when approved by the purchaser’s representative. Final closure welds are those welds where prefabricated piping is installed to a fixed component in the piping system and extensive purging would be required to weld successfully. Locations where backing rings have been used must be recorded on weld maps.

 

Carbon steel and chrome moly:  Root bead welding will be made by either (1) GTAW, (2) SMAW with the use of approved backing rings and girth joints (not included branch connections), (3) GMAW – short circuit if automated and rolled, or (4) GMAW – short circuit semi-auto on joints that cannot be rolled, but have access for visual inspection and grinding of the internal bead, as needed. The balance of the weld may be made using another approved welding process.

 

               Note:  GMAW short circuit is only permitted for making the root bead. GMAW shall not be used for stainless steel piping in oxygen service.

 

8.5.1.2   With Purchaser’s approval FCAW may be used with the following requirements:

 

  • Dual Shield Process.
  • The weld metal impact properties must meet or exceed that of the parent metal as demonstrated in a PQR.
  • Filler metal used in production shall be from the same lot or heat number used to qualify the WPS, when the base material is carbon or low alloy steel that requires impact testing.
  • The use of low hydrogen diffusible electrodes (H4 or H8) is mandatory.
  • Filler metal wire diameter shall be £1.2 mm (0.045 in).

 

8.5.1.3   Piping designated for oxygen or lube oil service shall have the root pass welded using the gas tungsten arc welding (GTAW) process with argon backing purge. Following the root pass, subsequent welding may be completed by another Air Products-approved process.

 

8.5.1.4   For carbon steel welding, each welder shall identify the welder’s specific production welds by stamping the welder’s regularly assigned identification number on the pipe adjacent to the welds made in all carbon steel material. Stamps shall be low-stress type with a round or “U”-shaped cross section.

 

8.5.1.5   For all metals except carbon steel, each welder shall identify the welder’s specific production welds by etching (with an electric pencil) the welder’s regularly assigned identification number on the pipe adjacent to the welds made in all stainless steel material.

8.5.2      For Aluminium Welding Requirements refer to Appendix D.

 

8.6          Impact Testing

 

8.6.1      When impact testing is a requirement of the parent material specification, the procedure qualification record (PQR) shall also include impact testing of both the weld metal and heat affected zone at the same or lower temperature.

 

8.6.2      The acceptance criteria for impact testing shall be the same as the parent material, unless more stringent requirements are specified in the purchase order and/or related contract documents.

 

8.6.3      When PWHT is required for PQR test coupons, the hold time at temperature shall be at least twice that planned for production to allow for weld repairs after the first PWHT.

 

8.6.4      Impact testing is required for consumables specified for equipment designed with an MDMT <-29°C (-20°F) regardless of code requirements.

 

8.7          Cryogenic Applications

 

8.7.1      Welding procedures for stainless steel as listed in ASME B31.3, Appendix A, shall be qualified to -196°C (-320°F) unless a lower temperature is specified in the design documentation.

 

8.7.2      Impact testing for weld procedure qualifications shall be according to ASME B31.3. For stainless steel in cryogenic service, the weld metal shall be Charpy impact tested with a minimum of 0.38 mm (0.015 in) lateral expansion for each specimen, with three specimens required per procedure qualification (see Appendix B, paragraph B 3.4). Charpy impact testing is not required for aluminium alloys in cryogenic service.

 

8.8          lnterpass Temperature

 

8.8.1      The maximum interpass temperature for austenitic stainless steels shall be 177°C (350°F) maximum.

 

8.8.2      Unless specified in the WPS, the preheat temperature shall also be considered the minimum interpass temperature and shall be maintained throughout the welding operation.

 

 

  1. BRAZING

 

9.1          Qualifications Required for Brazing Procedures and Brazers

 

9.1.1      The requirements for brazing shall be according to ASME B31.3, section 333.4. Silver brazing operators shall use approved techniques that will produce joints of 100% penetration of full socket depth consistently.

 

9.1.2      All pipe and tube brazing shall be made according to qualified procedures as developed by the contractor or supplier and by brazers qualified to the procedures according to ASME BPVC, Section IX, as required by ASME B31.3, section 333.1.

 

9.1.3      A minimum of fourteen calendar days before starting brazing the contractor or supplier shall submit to the purchaser’s representative two copies of all Brazing Procedure Specifications (BPS) and two copies of the Procedure Qualification Records (PQR) to be used on the project for approval.

 

9.1.4      The brazer qualification record shall be on file at the contractor’s job site office and a copy shall be given to the purchaser’s representative a minimum of two days before starting brazing. Qualification shall have been made within the time limits specified in the applicable code.

 

9.1.5      The cost of all qualifications shall be paid by the contractor.

 

9.2          Joint Materials

 

9.2.1      Brazed joints shall only be made with cadmium-free silver brazing alloy. Brazing filler materials for copper-to-copper, copper-to-stainless, and stainless-to-stainless braze joints shall meet the requirements of BAg-7 of ASME SFA 5.8. Brazing flux shall be an American Welding Society (AWS) brazing flux Type 3A.

 

9.3          Preparation

 

9.3.1      Brazed joints shall be kept as far as possible from threaded joints. The distance shall be sufficient to prevent the heat of soldering from destroying the sealing properties of the thread sealant.

 

9.3.2      Copper pipe and tube shall be cut to the desired length with a square cut in a square-end sawing vise or with a power saw and then deburred and cleaned. Tube cutters can only be used when the tube is internally deburred.

 

9.3.3      Pipe or tube and socket shall be cleaned to bright metal immediately before brazing. The pipe or tube shall be cleaned for a distance slightly more than the depth of the fitting socket. Cleaning shall be done carefully so that the proper clearance is maintained between the pipe or tube and fitting.

 

9.3.4      Flux shall be applied to both members immediately before brazing.

 

9.4          Inspection

 

9.4.1      Whenever possible, solder joints shall receive an internal visual inspection by optical inspection devices.

 

9.4.2      All joints that show evidence of overheating, cracking, poor penetration, or other defects of fit-up or workmanship shall be replaced as directed by the purchaser’s representative.

 

9.4.3      At the discretion of the purchaser’s representative, the contractor shall periodically monitor brazing operators’ techniques by cutting brazed joints out-of-line, then sawing them in half and pulling them apart. Defective joints and their repair shall be to the contractor’s account. Sound joints, which have been destructively tested as indicated above, will be paid for by Air Products.

 

9.4.4      If testing or visual inspection reveals unsound brazed joints the contractor shall disassemble and replace.

 

9.4.5      Each brazing operator shall identify the operator’s specific work by marking his regularly assigned identification symbol on the tube adjacent to the joint, at the time the joint is made.

 

10.          Shop PREFABRICATion of PIPING Spools

 

10.1       Drawings

 

Note:  This section does not apply when the same contractor fabricates and erects the piping.

 

10.1.1    The supplier shall submit a summary of the piece or spool numbers and related shop detail drawings for purchaser’s approval no later than three weeks after award of the contract.

 

10.1.2    The supplier shall submit three copies of certified shop detail drawings to purchaser within three weeks of receipt of the contract drawings.

 

10.1.3    One set of contract drawings shall be marked with piece numbers and returned to purchaser two weeks before any shipment of prefabricated pipe or assemblies.

 

10.1.4    The purchaser will provide these marked drawings to its field representative who will transmit them to the field installation contractor.

 

10.1.5    The above-mentioned drawings are for installation and record purposes only and submittal to purchaser does not relieve the supplier of the responsibility for configuration and fit-up of prefabricated pipe or assemblies.

 

10.2       Scheduling and Monitoring

 

Note:  This section does not apply when the same contractor fabricates and erects the piping.

 

10.2.1    Within two weeks after the award of the contract, the supplier shall provide to purchaser a planning schedule that details fabrication, cleaning, NDE, code inspections, stress relieving, painting, and shipping dates for all work.

10.3       Marking and Preparation for Shipment

 

Note:  This section does not apply when the same contractor fabricates and erects piping.

 

10.3.1    Each fabricated assembly shall be plainly tagged with the line number and piece mark. Line numbers shall correspond to those indicated on the contract drawings.

 

10.3.2    Supplier shall provide and install adequate weatherproof seals for all openings to ensure that the cleaning is maintained during fabrication, shipment, and while in storage at the job site (see capping requirements in Section 9 of 4WPI-SW70006).

 

10.3.3    Handling and storage of piping shall be as specified in 4WCE-600001.

 

10.3.4    Fabricated headers shall be suitably blocked and strapped to wooden pallets for shipment in a manner that will result in a minimum volume for the maximum number of fabricated pieces.

 

10.3.5    When specified, each item, crate, box, or pallet shall be marked with the purchaser’s name, complete purchase order number, and shipping address.

 

10.3.6    When specified, the shipment of material shall not be made until written approval is obtained from the purchaser’s representative.

 

10.3.7    Approval of fabrication by inspection or waiver of inspection shall not relieve the contractor or supplier of the responsibility to conform to the requirements for material, dimensional accuracy, workmanship, specification, or code requirements.

10.4       Fabrication Errors

 

Note:  This section does not apply when the same contractor fabricates and erects the piping.

 

10.4.1    The erection contractor shall immediately notify the purchaser’s representative of fabrication errors. Purchaser will then notify the supplier who shall take one of the following appropriate courses of action within 24 hours of error notification:

 

The supplier shall provide the appropriate fabrication personnel, tools, and welding equipment on-site to correct the problem.

 

The supplier shall authorize purchaser to instruct the contractor to perform the modifications at the supplier’s expense. The backcharge of these costs will be according to the applicable pricing agreement.

 

If purchaser does not receive instructions from the supplier within 24 hours, purchaser will issue a construction change order (CCO) to the contractor. All contractor costs for the corrective work will be backcharged to the supplier by Air Products.

 

 

11.          CLEANING OF PIPE AND ASSOCIATED SYSTEMS

 

11.1       The contractor shall be responsible for the cleanliness of all piping, fittings, in-line components, and gaskets fabricated or installed by the contractor. Cleanliness standards shall be according to 4WPI‑SW70001, 4WPI-SW70002, 4WPI-SW70003, or 4WPI-SW70004 as defined on the isometric index sheet. Methods for cleaning shall be as specified in 4WPI-SW70006. Special care must be taken to ensure that the specified standard of cleanliness is achieved and maintained.

 

11.2       Where pipe material is delivered with welded temporary pipe closures that meet the requirements of Air Products specification 4WPI-FWZC01 (for example, items that have been pressure tested and shipped with a purge gas); these should be removed as detailed in Air Products specification 4WCE-607001. Alternative removal procedures that ensure no debris will enter the system may only be used after a written procedure has been submitted and approved by Air Products.

 

 

  1. ASSEMBLY

 

12.1       General Pipe Work

12.1.1    Purchaser may identify field welds (FW) and field fit-up welds (FFW) on the piping isometric drawings. (These field welds are established to maintain an approximate shipping envelope of
2.4 m x 2.4 m x 12 m (8 ft x 8 ft x 40 ft) for prefabricated pipe spools. Straight runs of pipe are fabricated to double random lengths.) To accommodate misalignment of equipment or pipe connections, additional field welds are included on the isometrics at flanges and/or to provide short fit-up spools. The intent of these welds is to allow fit-up of pipe to equipment before completing final welds. The cost of rework that results from the failure to use these welds as intended will be considered to be the contractor’s account.

 

12.1.2    In place of manufactured tees (except in switch valve piping systems), reinforced branches (saddles) and welding bosses (such as weld-o-lets) of the proper material and adequate pressure rating may be used with written approval from the specifying engineer.

 

12.1.3    Whenever branch connections are specified, they shall be welded according to ASME B31.3, Chapter V, Figure 328.5.4.D. Branch connections shall not intersect the longitudinal seam of welded pipe headers.

 

12.1.4    The longitudinal seams of welded pipe in adjoining pipe sections shall be staggered 15 degrees or more.

 

12.1.5    Large fabricated tees and mitered bends shall be back welded on the inside of the fittings. For mitered bends in pipe sizes DN450 (NPS 18) and larger, an extra segment shall be included to allow inside welding.

 

12.1.6    All copper tube to stainless steel joints shall be silver brazed.

 

12.1.7    Pipe bends are permitted when identified in the applicable piping specification(s). Approval will be required from purchaser for all pipe bending.

 

12.1.8    Dresser couplings shall be installed as detailed in 4WPI-FWZM02.

 

12.1.9    Metallic expansion joints and flexible hoses shall be installed as detailed in 4WPI-FWZM01.

 

12.1.10  Pipe support attachments shall be installed as detailed in 4WPI-FWZM03.

 

12.2       Threaded Joints

 

12.2.1    All threaded joints shall be made with clean-cut taper threads conforming to the design requirements. Piping shall be reamed to remove burrs. Unions shall be provided as shown on the drawings or as required for proper assembly and disassembly. All threaded connections shall be with schedule 80 or greater.

 

12.2.2    All threaded joints shall be made using approved pipe thread sealants listed in 3PI55005. Substitution of other materials without prior written approval of purchaser is prohibited.

 

12.3       Flanged Joints

 

12.3.1    All flanged joints shall be installed in accordance with specification 4WPI-670210.

 

12.4       Orifice Flanges

 

12.4.1    Orifice flanges shall have an internal diameter equal to the connected piping. The weld bead on the internal surface shall be full penetration and ground flush to pipe and flange. Welds of orifice flanges shall be made without the use of backing rings. Backing rings shall be used for aluminium welds and removed after welding unless there is sufficient access to complete a double-sided weld.

 

12.4.2    Orifice plates shall be installed after blowout of the line is complete and before start of commissioning, unless otherwise agreed in writing by the purchaser’s representative.

 

12.5       Valves and Bellows

 

12.5.1    Contract documents will include a list of purchaser furnished valves to be installed by contractor. All other valves required by the contract drawings and these specifications shall be furnished and installed by the contractor.

 

12.5.2    Where necessary for shipment of cold boxes and other prefabricated units, valve top works, actuators, and junction boxes may have been removed. The contractor shall reinstate the dismounted items according to the contract documents.

 

12.5.3    In some circuits, valves are installed counterflow. Isometric drawings show the proper flow direction for all valves, and these flow directions shall be adhered to at all times.

 

12.5.4    Process control valves shall be installed by the contractor. These are indicated on the pipe work isometric drawings.

 

12.5.5    Safety relief valves shall be installed by the contractor. These are indicated in the pipe work isometric drawings.

 

12.5.6    The contractor shall note the following with respect to relief valves:

 

Whenever practicable, relief valves shall not be installed until all initial pressure testing and blowout work is completed.

 

The contractor shall inspect the relief valve. Any evidence of seal breakage, tampering, or fouling shall be brought to the attention of the purchaser’s representative.

 

The contractor shall remove the spring transport guard and shipping restraints before installing the cold box relief valves.

 

The contractor shall identify, tag, and deliver the relief valve spring transport guards and shipping restraints to the Purchaser’s representative.

 

12.5.7    Before welding any valve, the contractor shall position the valve as recommended by the manufacturer (for example, fully open or fully closed) to prevent thermal distortion of the valve seat components.

 

12.5.8    The contractor shall dismantle soft seat valves before welding to avoid causing damage to the seats, and reassemble after valve has cooled to ambient temperature.

 

12.5.9    All valves will be supplied with identifying tags. The contractor shall be responsible for ensuring that tags remain attached during installation. Valves must be installed in the location corresponding to their tag number. It is not permitted to interchange valves.

 

12.6       Piping Tolerances

12.6.1    Tolerances shall be as specified by the Piping Fabrication Institute (PFI) unless specifically detailed otherwise on contract drawings and specifications.

 

12.6.2    All flanges and connections to mechanical rotating equipment (such as centrifugal compressors, pumps, expanders, and companders) shall be unbolted and checked for proper alignment. Flanges shall not put any strain on equipment casings. Corrections to piping to permit proper alignment shall be to the contractors account.

 

 

  1. FIELD ERECTION

 

13.1       General Field Erection

 

13.1.1    The contractor shall erect the pipe work defined by the contract drawings.

 

13.1.2    Welders shall have in their possession the WPS for the processes they are welding. These WPSs shall be available to purchaser’s representative upon request.

 

13.1.3    Nozzles on supplied equipment shall be cut and prepared for welding according to the contract drawings.

 

13.1.4    Where nozzles on supplied equipment are delivered with welded temporary pipe closures that meet the requirements of Air Products specification 4WPI-FWZC01 (for example, items that have been pressure tested and shipped with a purge gas); these should be removed as detailed in Air Products specification 4WCE-607001. Alternative removal procedures that ensure no debris will enter the system may only be used after a written procedure has been submitted and approved by Air Products.

 

13.1.5    The contractor shall protect all materials from damage caused by weld slag.

 

13.1.6    Heating to align pipe for fit-up shall not be permitted without the express written approval of the purchaser.

 

13.1.7    When handling painted spools, the contractor shall use synthetic slings or chokers to prevent damage to the paint coating. The cost of any rework to the paint coating will be to the contractor’s account.

 

13.1.8    The use of purge dams is not permitted unless approved by the purchaser’s representative.

 

13.2       Equipment and Pipe Supports, Guides, and Anchors

 

13.2.1    The contractor or supplier shall furnish and install all materials, equipment, pipe supports, guides, and anchors required by the contract drawings, this specification, and 4WPI-AWS002. The contractor shall adequately and permanently support all piping DN65 (NPS 2 1/2) and smaller as part of the contract work in accordance with 4WPI-AWS002.

 

13.2.2    As permanent supports are installed, the contractor shall remove temporary supports.

 

13.2.3    The contractor shall furnish and install anchor bolts, expansion shields, and bolts as required to erect and attach supports.

 

13.2.4    All supports attached to pressure-containing piping or equipment shall be welded and examined before pressure testing. If necessary to weld to a line that has been pressure tested, follow the requirements of specification 4WPI-FWZM03.

 

13.2.5    Welding onto a process line that is in service is not permitted.

 

 

  1. WELD EXAMINATION AND INSPECTION

 

14.1       The minimum examination of all materials and workmanship shall be according to the requirements of ASME B31.3, section 341 for normal service conditions unless otherwise specified on contract documents or attached Appendices. The examination may be performed at any place where fabrication and installation is performed.

 

14.2       Radiography

 

14.2.1    Radiography of welds shall be performed according to ASME BPVC, Section V, Article 2, and shall be judged according to ASME B31.3, “Normal Fluid Service,” unless otherwise indicated.

 

14.2.2    All welding shall be subject to radiographic examination according to ASME B31.3, Normal Fluid Service unless stated otherwise, and shall include examination by random radiography of the total quality of the welded joints, including saddle-type branch connections as follows:

 

Radiography shall be done progressively throughout the work, beginning at the start of fabrication and/or field erection welding.

Each welder’s work for each procedure used shall be represented.

The quality of each welder’s work, as evidenced by radiographic results, shall be considered in selecting welds for additional radiographic examination.

The severity of process service shall be considered.

Weld joints shall be selected at a frequency to preclude significant rework if systematic weld quality issues are discovered.

The purchaser’s representative shall have the privilege of selecting the welds to be examined.

 

14.2.3    All radiographs shall show a 2% sensitivity based on single pipe wall thickness.

 

14.2.4    Aluminium piping should be examined using X-ray techniques (not isotope). Deviations (that is, use of isotope with ultra fine grain ASTM E-1825, Class 1 film) are to be approved by purchaser on a case-by-case basis for instances where x-ray is not practical. Air Products will not accept the use of high energy sources such as Iridium 192 or Cobalt 60, but will accept the use of Selenium 75 on pipes 10 mm and thicker (assuming a double wall technique). For thicknesses less than 10 mm (13/32 in) Air Products would only accept the use of Ytterbium 169 (double wall). The absence of suitable X-ray equipment is not a justification for a request to use isotopes. Geometry and space limitations are suitable reasons. For thicker walled pipes (10 mm and over) ultrasonic examination may be requested subject to submission and approval of suitable procedures and examination personnel qualifications.

 

14.2.5    100% radiographic examination is required for all prefabricated and field-installed process piping when conditions exist as follows:

 

All welded connections of oxygen-compressor interstage or discharge piping, up to the first valve or equipment flange.

 

All welded connections on liquid withdrawal piping outside cryogenic liquid storage tanks, up to the first external emergency shut off valve.

 

For Incoloy 800H, all butt welds shall be 100% radiographed.

 

14.2.6    The minimum radiographic examination for circumferential butt welds shall be as defined in Table 1. The first two production welds per WPS produced by each welder shall be radiographed. Production welding shall not resume until the welder produces two acceptable welds per welding procedure.

 

Table 1 – Minimum Requirements for Radiography

 

  Piping Service Min. % of Random Radiography
Comments
  Oxygen 5% 100% visual inspection
(reference Notes A and C)
  Nitrogen 5% (reference Notes B and C)
  Other 5% Unless otherwise specified in contract documents (reference Notes B and C)

 

               Note A:  100% of welds on pipework designated for oxygen service shall be visually examined to ensure that the internal root profile is smooth, free from overpenetration, irregular profile, weld splatter, excessive oxide formations, or other imperfections. If the root pass cannot be visually examined, that weld shall be subjected to 100% radiographic examination. This does not apply to aluminium welds with permanent backing strips.

 

               Note B:  Any additional examination required because of the nature of the contents or service of the piping system will be specified on the contract drawings and specifications.

 

               Note C:  Additional NDE is required for pneumatically pressure tested piping that are categories I, II, or III under the European Pressure Equipment Directive. These requirements are defined in Appendix B, but may be summarized as 10% minimum random radiography. Lines classified as SEP do not require additional random radiography.

 

14.2.7    Radiography shall be performed on all weld repairs.

 

14.2.8    For each defective weld found, two additional (tracer) joints made by the same welder shall be radiographed. If these tracers fail examination, two welds for each failed tracer weld shall be radiographed. Should any of the second set of tracer welds be defective, then all welds made by this welder shall be examined. Welds radiographed as tracer joints are not counted as part of the 5% sampling check. The contractor or supplier shall reimburse purchaser at the laboratory’s quoted rates for radiographic re-examinations and radiographs related to tracers.

 

14.2.9    Each film shall be marked with the line number and weld number according to the acceptance criteria detailed in ASME B31.3. The radiographic films shall become the property of Air Products.

 

14.2.10  The minimum examination required for brazed joints shall be 5% according to ASME B31.3.

 

14.2.11  Examination by sectioning is prohibited.

 

14.2.12  The contractor or supplier shall keep sufficient records to permit reviewing the performance of each welder during the progression of the work.

 

14.2.13  The contractor shall maintain an accurate weld map indicating field-weld locations and the welder who performed each weld.

14.3       Dye Penetrant Examination

 

14.3.1    Incoloy 800H socket welds shall be dye checked.

 

14.3.2    All Dye Penetrant examination shall be completed before painting in accordance with ASME BPVC, Section V, Article 6.

 

14.3.3    The requirements of Appendix B must be implemented for equipment manufactured to the European Pressure Equipment Directive.

14.3.4    The purchaser’s representative reserves the right to select the joints for examination, within the limitation of the above requirements.

 

 

  1. PUNCHLISTING

 

15.1       Punchlisting shall be conducted by the contractor as detailed in specification 4WCE-600001.

 

15.2       In certain circumstances, and with the agreement of the purchaser’s representative, punch list items may be prioritized thus:

 

  • Category “A”:  A nonconformance that must be rectified before pressure testing of the system.
  • Category “B”:  A nonconformance that can be rectified after pressure testing of the system.

 

When all category “A” items have been rectified and accepted as complete by the Purchasers representative, the contractor may request permission to pressure test the system.

 

 

  1. PRESSURE TESTING

 

16.1       Prefabricated piping shall be tested in the field, after installation in accordance with 4WCE-600001.

 

16.2       Pressure testing of piping and equipment shall be performed according to 4WPI-EW44001.

 

16.3       Piping may be insulated before pressure testing with approval of the Purchaser’s representative. However, all welded joints and flanges shall be left exposed until testing is completed.

 

16.4       Radiography shall not be substituted for a pressure test unless approved by the Purchaser’s representative.

 

17.          PAINTING

 

17.1       After the pipe spools are completely fabricated and capped, the contractor or supplier shall paint all piping according to the requirements listed in the job-specific specification and according to 4WEQ-6804.

 

17.2       After piping erection, the contractor shall touch up unprimed welded or damaged areas for all piping at the job site.

 

 

  1. PROCESS SAFETY MANAGEMENT (PSM) DOCUMENTATION

 

18.1       A list of required documents for piping systems is detailed in Table 2. The contractor shall collect and submit the required documents to the purchaser’s representative.

 

18.2       Material Test Reports (MTRs) are required for all piping components.

 

Table 2

Process Safety Management (PSM) Documents    Y=Yes

  DOCUMENT  OR  DELIVERABLE TITLE Required Before Start of Fabrication or Erection
Required to be Maintained During Course of Work
Submitted After Fabrication or Erection Complete
         
  WELDING AND MATERIAL REPORT DOCUMENTS FOR EQUIPMENT, SKID PIPING, AND PRE-FAB PIPING      
         
  Weld and Braze Procedure Specification (WPS/BPS) for each type of weld and braze joint Y
  Weld and Braze Procedure Qualification Records (PQR) Y
  Welder and Brazer Qualification Performance Test/Testing for every welder and Brazer Y _ _
  Weld Map showing Weld Joints, Weld Procedure, Radiograph Locations and Welder Identification      (Logs on Piping Isometrics) Y Y
  Mill Test Reports (MTRs) – For All Pressure Vessels Y
  Mill Test Reports (MTRs) – For All Plant Piping on Skids and for Pre-Fab Piping Y
  Material Certificates of Compliance—Pre-Fab Piping and Piping on Skids Y
  Radiography Logs and Reports—For Pressure Vessels Y Y
  Radiography Logs and Reports—For All Plant Piping on Skids and for Pre-Fab Piping Y Y
  Radiograph X-Ray Films (Fabricator shall retain films for at least five years after the record is generated according to ASME B31.3, Chapter VI and ASME BPVC, Section VIII, Div. 1) Y Y
  Inspection Certifications for Nondestructive Testing Results  [such as Dye Penetrant Tests, Magnetic Particle Tests, Ultrasonic Tests, and Others] Y Y
  Pressure Test Reports or Certificates (For Non-Pressure Vessels) Y
  Heat Treatment Charts/Certificates Y Y
  Positive Material Identification (PMI) Records and Logs—For Skidded Equipment and Pressure Vessels Y Y
         
  CONSTRUCTION DOCUMENTS FOR FIELD ERECTION AND WELDING      
  Weld and Braze Procedure Specification (WPS/BPS) for each type of weld and braze joint Y
  Weld and Braze Procedure Qualification Records (PQR) Y
  Welder and Brazer Qualification Performance Test/Testing for every welder and Brazer Y _ _
  Weld Map showing Weld Joints, Weld Procedure, Radiograph Locations and Welder Identification  (Logs on Piping Isometrics) Y Y
  Mill Test Reports (MTRs)—For All Plant Piping Fabricated in Field Y Y
  Radiography Logs and Reports Y Y
  Radiograph X-Ray Films for All Types of Welds Y Y
  PMI Records   Y Y
  PWHT Records including charts   Y Y
  Inspection Certifications for Nondestructive Testing Results  [such as Dye Penetrant Tests, Magnetic Particle Tests, Ultrasonic Tests, and Others] Y Y
         
  OTHER CONSTRUCTION DOCUMENTS      
  Positive Material Identification (PMI) Records and Logs—For piping, piping components, and equipment Y Y
  Bolt Torquing Records Y Y
  Stress Relief Charts for Required Lines Y Y
  Brinell Test Reports Y Y
  Spring Setting Records for Spring Hangers Y Y
  Refractory Test Results Y Y
  Coded Pressure Vessel Modifications Y Y
  Field Piping Pressure Test Certificates Y Y
         

 

  1. CHANGE LOG

 

Appendix A

HyCO Project Piping

 

A1.          scope

 

A1.1       This Appendix is intended for use on high temperature hydrogen and carbon monoxide plants or as specified for a project.

 

A1.2       This Appendix shall be used in conjunction with the general requirements for process piping of this specification and the Project Specific Scope of Work.

 

A2.          related documents

 

A2.1       American Petroleum Institute (API)

 

STD 560        Fired Heaters for General Refinery Services

RP 582          Welding Guidelines for the Chemical, Oil, and Gas Industries

 

A2.2       NACE International

 

MR0103         Materials Resistant to Sulfide Stress Cracking in Corrosive Petroleum Refining Environments

 

SP0472         Methods and Controls to Prevent In-Service Environmental Cracking of Carbon Steel Weldments in Corrosive Petroleum Refining Environments

 

A3.          GENERAL

 

A3.1       All power boiler piping shall be stamped accordingly by the manufacturer and installed as required by the appropriate code and the site-specific authorized inspector.

 

A3.1.1    External pipe welding between the steam drum and the process gas boiler can be performed using a “PP” Stamp under ASME B31.1 Guidelines 2 or local equivalent.

 

A3.1.2    Flue gas coil pipe welding will be performed using an “S” Stamp according to Section I of the ASME Code, Power Boilers, or local equivalent.

 

A3.2       Welding Guidelines for the Chemical, Oil, and Gas Industries as provided in API Recommended Practice 582 are to be followed unless there is a conflict with the requirements of this specification. In the case of a conflict, the requirements contained in this specification shall govern.

 

A3.3       Piping and equipment fabricated from either nonferrous alloys or stainless steels shall be stored and fabricated in a clean environment to inhibit contamination. These components shall be segregated from ferrous materials.

 

A3.4       Permanently installed backing rings or strips shall not be used without prior written approval by Air Products. In no case shall they be used for steam service.

 

A3.5       The use of stud-welding devices on pressure-boundary components of pressure vessels and heat exchangers is prohibited. Stud-welding is permitted on ductwork.

 

A3.6       Vertical welding shall be performed in the vertical-up position for all processes.

 

A3.7       Weaving of the electrode shall be limited to a maximum of 3 times core wire diameter or 13 mm (1/2 in), whichever is smaller. For nickel-based alloys, weaving shall be limited to 1.5 times the wire diameter on either side of the weld centerline. More restrictive limits shall be considered for applications where heat input must be limited, to achieve impact properties for example.

A3.8       Weld joints shall be made by completing each layer before deposition of subsequent passes. Block welding is not permitted.

 

A3.9       The maximum, individual, weld-layer thickness shall not exceed 9.5 mm (3/8 in) for materials thinner than 32 mm (1 1/4 in), or 13 mm (1/2 in) for materials that are equal to or greater than 32 mm (1 1/4 in) thick.

 

A3.10     Requirements herein that pertain to specific services such as wet H2S, or fatigue shall apply when stated in the purchase order and/or related documents.

 

A3.11     Deviations from this Appendix require written approval by Air Products.

 

A3.12     All pressure boundary welds in hydrogen service shall exhibit full penetration. In hydrogen service piping all root passes shall be made using the GTAW process.

 

A3.13     The contractor and supplier shall have a quality assurance program in place to ensure traceability of all material installed.

 

A3.14     Nondestructive examination (NDE) requirements on circumferential pipe welds (both shop and field) shall be performed as indicated in the logic chart shown in Figure A1.

Figure A1

Nondestructive Examination (NDE) Logic Diagram

Definitions and Notes for Figure A1

 

  • Cyclic service:  Thermal or pressure cycles that produce the equivalent effect of “Severe Cyclic Service” as defined by ASME B31.3, section 300.2.
  • P&T are design pressure and temperature, respectively.
  • RT = radiographic examination.
  • PT = dye penetrant examination.
  • MT = magnetic particle examination.
  • MT and PT:  Root and cover pass of buttwelds, plus finished attachment welds.
  • For joints where RT is not practical, MT or PT root and cover pass may be performed.
  • Basis for P, T, t breakpoints:  ASME B31.1.
  • Code rules apply where more restrictive.
  • API STD 560 rules apply to furnace piping.

 

A3.15     Pressure Testing

 

A3.15.1  Pressure testing shall be performed as required by Section 16 of this specification and as follows:

 

  • Pressure testing of the “boiler system” shall be performed according to ASME B31.1 or ASME Section I, depending on the service. Pressure testing shall be performed by the system installer who provides the ASME “S” stamp or local equivalent.

 

  • Piping shall be hydrostatically tested, unless the presence of water will damage components incorporated in the test. Pneumatic testing shall be approved by the Purchaser’s representative.

 

  • Furnace components in the scope of API 560 shall be pneumatically pressure tested when hydrostatic testing is not practical.

A4.          WELDING PROCEDURE QUALIFICATION

 

A4.1       Essential Variables

 

A4.1.1    In addition to the code essential variables, the grade of flux for SAW only shall be considered as an essential variable.

 

A5.          Hardness Testing

 

A5.1       For alloy steels in wet H2S service, PQRs shall include microhardness surveys across the weld, extending from the parent material through the heat-affected zone and into the weld metal. Acceptance criteria shall be Table 2 of NACE standard MR0103.

 

A5.1.1    Hardness testing of deposited weld material and heat-affected zone per NACE Standard SP0472 is required as part of the PQRs intended for P-1 materials used in wet H2S service.

 

A6.          Chemical Analysis

 

A6.1.1    PQRs for weld overlays shall include the complete chemical analysis of the deposited weld metal overlay taken from a depth 1.6 mm (1/16 in) below the weld deposit exposed surface. The consumable manufacturers’ weld metal analysis in lieu of the above requirements is not acceptable.

 

A6.1.2    For austenitic stainless steels the ferrite content of the welding consumables measured by a ferrite gauge shall be in the 3 to 9 % range.

 

A7.          INSPECTION AND EXAMINATION

 

Under special circumstances (difficult fit-up, awkward geometry, high degree of difficulty) 100% NDE is a requirement and shall be imposed at the discretion of the Purchaser’s representative.

 

A7.1       Acceptance NDE shall be performed after PWHT.

 

A7.2       Welds shall be ground smooth if the weld profile inhibits the interpretation of nondestructive examinations.

 

A7.3       Radiographic Inspection

 

A7.3.1    Fine-grain or ultrafine-grain film shall be used.

 

A7.3.2    Only lead screens shall be used.

 

A7.3.3    Radiography of welds in pipe having a diameter of DN80 (NPS 3) or less may be performed by the elliptical projection technique. At least two separate exposures are required at locations 90 degrees apart.

 

A7.3.4    Welds of a size or type that prevent conclusive radiographic images to be interpreted (for example, some types of branch connections and fillet welds) shall be subject to ultrasonic (UT), magnetic particle (MT) examination, or a liquid penetrant (PT) examination as defined in the purchase order and/or related documents.

 

A7.4       Magnetic Particle and Liquid Penetrant Inspection

 

A7.4.1    When possible, AC magnetic yokes shall be used.

 

A7.4.2    The use of prods shall be limited to castings.

 

A7.4.3    For nonmagnetic materials PT examination shall be substituted for MT examination.

 

A7.4.4    For welds in amine service, wet H2S service, or fatigue service wet fluorescent magnetic particle testing is required.

 

A7.4.5    All equipment in flammable gas service requiring PWHT shall have all pressure-containing welds and all attachment welds to pressure parts 100% MT examined after PWHT.

 

A7.5       Hardness Testing

 

A7.5.1    Hardness testing after PWHT is required for all chrome-moly materials.

 

A7.5.2    Hardness testing of all butt welds in carbon steel pipe in wet H2S service is required. Testing shall be in accordance with NACE Standard SP0472.

 

A8.          DOCUMENTATION                                                                                                  

 

A8.1       The fabricator shall have the following documents available for review by Air Products. Document submittal and approval requirements will be defined in the purchase order and related documents.

 

  • Welding Procedure Specifications
  • Procedure Qualification Records
  • Welder Qualification Records
  • Weld Maps
  • Welding Consumable Handling Procedure
  • NDE Procedures
  • NDE Results
  • PWHT Procedure
  • PWHT time-temperature charts

 

A8.2       The welding consumable handling procedure shall include electrode baking times and temperatures, handling methods and maximum time out of the oven, re-baking requirements, and electrode rejection criteria.

 

A8.3       Welding procedure specification numbers shall be referenced on all drawings, isometrics, and weld maps, showing location of use.

 

A8.4       For equipment, the WPS numbers, PQR numbers, and thicknesses to be welded for each location shall be defined when WPS’s and PQR’s are submitted for review.

 

A8.5       For welding of cast material, a Procedure Qualification Record (PQR) must be submitted using the same material as the production weld. Substitution of similar wrought or cast material will not be permitted.

 

A8.6       Pipe welds in special or unusual circumstances shall be 100% radiographed according to ASME requirements. The isometric drawings will indicate which radiography or nondestructive examinations (NDE) will be required.

 

A9.          WELDING PROCESSES

 

A9.1       Permissible welding processes shall be as specified in API RP582, with the following exceptions.

 

A9.1.1    Electrogas welding (EGW) is not permitted.

 

A9.1.2    FCAW shall not be used in the following services:

 

  • Wet H2S or amine service.
  • MDMT less than -40°C (-40°F).
  • Hydrogen PSA Adsorber Vessels

 

A9.1.3    For steels containing more than 2% chromium, nitrogen shall not be used for internal purge gas. An internal purge of argon or other inert gas shall be used for all GTAW root passes when joining steels contain more than 2% chromium.

 

A9.1.4    Intermediate spool pieces of alloy 800H or buttering the ferritic side of the transition joint with ERNiCr-3, ENiCrFe-2, ENiCrFe-3 is recommended for dissimilar weld joints requiring PWHT. PWHT the ferritic side of the joint after buttering, and complete the butt weld with no subsequent PWHT to avoid sensitization of the austenitic side of the weld.

 

A10.       THERMAL TREATMENT

 

A10.1     Preheat

 

A10.1.1  Preheat all joints to a minimum of 52°C (125°F) when moisture removal is required.

 

A10.1.2  Preheat carbon steel joints to 107°C (225°F) when the weld thickness exceeds 25 mm (1 in) or when the carbon equivalent of the parent material exceeds 0.42.

 

A10.1.3  Carbon equivalent (CE) shall be calculated using the following formula:

 

               CE = C + (Mn)/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

 

A10.1.4  In the event that the chemical composition of the parent material contains insufficient analysis to use the above formula, the CE shall be calculated using:

 

               CE = C + Mn/6 + 0.05

 

A10.1.5  Preheat carbon steel joints to 149°C (300°F) when the weld thickness exceeds 50 mm (2 in) or when any integrally reinforced connections greater than 25 mm (1 in) thick are being welded into a vessel or large diameter pipe (for example, weldolets).

 

A10.1.6  When the specified preheat is 149°C (300°F) or higher, the metal shall be maintained at the preheat temperature until the weld is complete (including periods when no welding is taking place). The use of blankets shall be used only to assist in heat retention.

 

A10.1.7  For welds with thicknesses over 50 mm (2 in) and/or under a high degree of restraint, the preheat temperature shall be maintained until welding is completed.

 

A10.1.8  Use of electrical heating elements for preheat is preferred. Alternately natural gas and propane may be used for preheating. An oxyacetylene flame tip is permitted for preheating if only a rosebud tip is used and a neutral flame is maintained.

 

A10.1.9  For welding of castings, the whole casting shall be maintained at the minimum preheat temperature throughout the welding operation, including any breaks in welding.

 

A10.1.10 Preheat of low alloy steels is required, regardless of thickness and service. Minimum preheat temperatures are:

 

  • P-4 Gr. 11 (1 1/4 Cr 1/2 Mo)        300°F (150°C)
  • P-5 Gr. 22 (2 1/4 Cr 1 Mo)           350°F (175°C)
  • P-5B Gr.P91 (9 Cr 1 Mo V)            350°F (175°C)

 

A10.2     Postweld Heat Treatment (PWHT)

 

A10.2.1  PWHT is mandatory for all carbon steel components in amine (for example, MEA and aMDEA) service.

 

A10.2.2  PWHT is required for all carbon steel and low alloy steel components fabricated from plate material when in wet H2S service.

 

A10.2.3  PWHT of piping components and pressure vessels fabricated from pipe material is not required.

A10.2.4  The minimum temperature for PWHT shall be 607 ±13°C (1125 ±25°F) for carbon steels and the soak time shall be one hour per 25 mm (1 in) of thickness with a minimum time of one hour, or in accordance with applicable code requirements, if more stringent.

 

A10.2.5  PWHT of low-alloy steel components is required, regardless of code exemptions when the service environment can contain contaminants known to promote stress-corrosion cracking (for example, HCN, KOH, NaOH, CO, and HF). The soak time shall be one hour per 25 mm (1 in) of thickness with a minimum time of one hour. The following PWHT temperatures are required for given low-alloy steels:

 

  • P-4 Gr. 11 (1 1/4 Cr 1/2 Mo)  1250 ±25°F (677 ±14°C) for equipment and 1350 ±25°F (732 ±14°C) for piping

 

  • P-5 Gr. 22 (2 1/4 Cr 1 Mo)     1275 ±25°F (690 ±14°C) for equipment and 1375 ±25°F (746 ±14°C) for piping

 

  • P-5B Gr. P91 (9 Cr 1 Mo V)     1400 ±25°F (760 ±14°C) for piping, if tempering temp. >1425°F (>774°C)

 

A10.2.6  Sufficient thermocouples shall be properly attached to the work piece so that accurate temperature readings can be attained. The use of furnace thermocouples shall not be used to verify metal temperatures.

 

A11.       FIELD CONTRACTOR DOCUMENTATION REQUIREMENTS

 

A11.1     Any ASME nonconformance shall be submitted to the purchaser’s representative, who will then send this information to supplier/engineer and its Authorized Inspector (AI) for resolution.

 

A11.2     Original ASME P-4A data report for field-fabricated ASME B31.1 spools shall be prepared and submitted to the purchaser’s representative. These documents are to be prepared by the contractor or his “PP” sub-contractor.

 

A11.3     The back of the ASME P-4A data report originals submitted by the shop spool fabricator shall be completed by the contractor or his “PP” subcontractor.

 

A11.4     The assembly details on the ASME P-4A data report originals shall be completed by the contractor or his “PP” subcontractor.

 

A11.5     The ASME P-3A data report original prepared by supplier/engineer shall be signed off by the contractor.

 

A11.6     The steam system contractor’s nameplate (“S” or “A”) on the steam drum shall be prepared and affixed by the contractor.

 

A11.7     On completion of the above documents, the purchaser’s field representative will forward all originals to the supplier/engineer who will then assemble the overall data report package.

Appendix B

 

Requirements of the European Pressure

Equipment Directive

 

B1.       SCOPE

 

B1.1    The European Pressure Equipment Directive (PED) applies to pressure systems located within the European Economic Community (EEC), or when specifically stated in the contract documents. New plant construction, site-built cold boxes, the complete replacement of an existing item or items of pressure equipment, and important modifications (modifications that change an existing item or pressure system’s original characteristics, purpose and/or type) are included within the scope of the PED, and the requirements listed in this appendix will apply.

 

            Note:  Repairs or minor modifications (modifications that do not change an existing item or items of pressure equipment’s original characteristics, purpose and/or type) are outside of the scope of the PED and the requirements listed in this appendix will therefore not apply.

 

B2.       GENERAL

 

B2.1    When the work involves Category II, III, or IV equipment, it shall be performed under a conformity assessment module that includes surveillance of manufacture by a notified body. This is in addition to the inspections performed by the purchaser according to ASME B31.3. The use of a conformity assessment module based on quality assurance is not acceptable to Air Products.

 

B2.2    The purchaser will employ a notified body to perform surveillance of manufacture at site on Category II (module A1), Category III piping (modules B1+F), and Category IV assemblies (module G). The costs associated with the surveillance of manufacture by a notified body, as described in paragraph B2.1, shall be to Air Products’ account. Any additional re-inspections required will be to the contractor’s account. The contractor shall work in harmony with the Air Products nominated notified body and shall be responsible for calling the notified body to site as necessary.

 

B3.       WELDING PROCEDURES AND QUALIFICATION, AND OTHER JOINTING METHODS

 

B3.1    For Category II, III, and IV equipment, the welding procedures and personnel shall be approved by a competent third party as required by Section 3.1.2 of Annex 1 of the PED, or national legislation implementing the PED. The competent third party may be either a body appointed by a member state according to Article 13 of the PED, or a notified body appointed by a member state according to Article 12 of the PED. In both cases the details of the bodies shall have been published in the Official Journal of the European Communities by the Commission.

 

B3.2    The requirements listed in paragraph B3.1 shall apply equally to all methods of permanent joining including (but not limited to) such methods as brazing, riveting, or adhesive bonding.

 

B3.3    The contractor shall ensure that all details and records of the welding procedures and personnel, as approved by a competent third party, are included within the QA/QC documentation.

 

B3.4    For stainless steel weldments in cryogenic service below -80°C (-112°F) and down to -196°C
(-320°F), weld procedures qualification tests on material over 6 mm (1/4 in) shall have impact tests at -196°C (-320°F) in the weld; over 20 mm (3/4 in) thick two sets are required at position per EN 1252 or CEN-EN-ISO-15614-1. A value of 40 joules is required. For service temperatures below -196°C additional requirements will be specified by Air Products.

 

B3.5    For ferritic steels all  Welding Procedure Qualifications (PQR) shall have impact tests at the minimum design temperature, or lower, even when it is above29°C (-20°F) regardless of code requirements. The minimum requirement is an average (3 pieces) of 27 joules in both the weld metal and heat affected zone.

 

B 3.6   Section 8.2 of this specifications requires welding documentation to comply with ASME BPVC Section IX and as modified by ASME B31.3, section 328.2; however, existing Welder and Welding Operator Qualifications meeting EN or ISO Standards can be accepted with the agreement of the Notified Body, since these are at least as stringent as ASME.

 

8.3.7   Welding Procedures (WPS) and Procedure Qualifications (PQR) must always comply with ASME because the justification of the Air Products  piping design has been based on the essential variables contained in these codes.

 

B4.       NONDESTRUCTIVE TESTING (NDT)

 

B4.1    The PED requires that NDT shall only be performed by suitable qualified and competent personnel. For NDT performed on pressure equipment in Categories III and IV, the personnel must be approved by a third party organization recognized by a member state pursuant to Article 13 of the PED. The details of this third party organization shall have been published in the Official Journal of the European Communities by the Commission.

 

B4.2    Contractor shall ensure that all details (such as resumes, experience, and qualifications) of all inspecting personnel be submitted with the NDT reports, and included within the QA/QC documentation. Where an inspector performs work on Category III and/or Category IV pressure equipment, a certificate of approval issued by an approved third party organization and relating to that inspector shall also be submitted.

 

B4.3    Additional NDE is required for pneumatically-tested piping systems. The minimum requirements for Category I, II, and III piping fabricated in aluminium, 300 series stainless steel, Monel, and carbon steel is as follows:

 

  Type of Weld Extent of NDE
  Circumferential butt welds 10% RT or UT

DN≤600, 10% of all welds to be tested

DN>600, 10% of total weld length to be tested (crossings with longitudinal welds to be covered, such as ‘Tees’)

  Branch welds DN ≥100 10% RT or UT

DN≤600, 10% of all welds to be tested

DN>600, 10% of total weld length to be tested (crossings with longitudinal welds to be covered, such as ‘Tees’)

  Branch welds DN <100 5% of aluminium welds to be 100% dye penetrant examination and 10% of other welds to be 100% dye penetrant examination (magnetic particle examination on ferritic materials may be substituted) (crossings with longitudinal welds to be covered, such as ‘Tees’)
  Socket welds DN<60 5% of aluminium welds to be 100% dye penetrant examination and 10% of other welds to be 100% dye penetrant examination (magnetic particle examination on ferritic materials may be substituted)
  Branch weldolets ≥60 25% of welds to be 100% dye penetrant examination (magnetic particle examination on ferritic materials may be substituted)
  Longitudinal welds in pipe 100% RT or UT (if not previously subject to 100% NDE or hydrotesting by the pipe manufacturer)

See Note B.

  Longitudinal welds in fittings 10% RT or UT (if not previously subject to 100% NDE or hydrotesting by the fitting manufacturer)

 

Note A:  Where the material of construction is not as in B4.3, details must be agreed with Air Products based on additional NDT, in addition to table 8.2.1 of EN 13480 part 5 (for example, materials such as Duplex stainless steel, alloy ferritic steels).

 

            Note B:  This may be reduced to 10% for aluminium alloys when the manufacturer can demonstrate consistent results using mechanized welding equipment.

 

Sound Engineering Practice (SEP) piping is excluded from these additional requirements.

 

B5.       QA/QC DOCUMENTATION

 

B5.1    The contractor shall prepare two identical copies of the QA/QC documentation according to the requirements of 4WCE-600001 and the PED. These dossiers shall then be submitted to the purchaser’s representative after completion of the work, or at a time mutually agreed between the contractor and the purchaser.

 

B5.2    Records of welding consumables and other jointing materials purchased by the contractor shall be maintained during the construction phase and included within the QA/QC documentation, and shall meet the requirements of BS EN 10204 type 2.2.

 

B5.3    For work performed on Category II, III, or IV equipment, the contractor shall obtain from the purchaser’s appointed notified body a certificate of conformity relating to the inspections performed. As a minimum this certificate will confirm that the measuring and test equipment was properly calibrated, that all materials have certificates conforming to the requirements of the PED, that all jointing procedures are properly qualified, and that all NDE operators are appropriately qualified. This certificate shall be included within the QA/QC documentation.

 

B6.       MATERIALS

 

B6.1    Where contractor supplies materials (including welding consumables and other jointing materials) for use in pressure systems, he shall demonstrate by means of certification that the material supplied conforms to the required specification. Certification requirements are specified in the relevant material purchase specification, which are issued by purchaser to the contractor as part of the contract documentation.

 

            Note 1:  BS EN 10204 type 3.1 certificates must indicate which accreditation authority has approved the supplier’s QA system. If this is not the case, then the supplier’s QA accreditation certificate must also be supplied.

 

Note 2:  The supplier’s QA accreditation body must be a competent body established for that purpose within the community. If the supplier’s QA body is not established within the community, then BS EN 10204 type 3.2 certificates authorized by a notified body are required.

 

B6.2    Plate and sections known to be for structural or non-pressure parts and pressure pipes less than or equal to DN25 may be accepted with a BS EN 10204 type 2.2 certificate. Welding consumables can be ordered/accepted with BS EN 10204 type 2.1 certificates (certificate of compliance).

 

B6.3    Stainless plate and pipe thicker than 20 mm (3/4 in) shall be impact tested at +20°C (68°F) where the service temperature is below -80°C (-112°F) and down to -196°C (-320°F). Tests in transverse direction require the (material) specification value with a minimum of 40 Joules. For service temperatures below ‑196°C (-320°F) additional requirements will be specified by Air Products.

 

B6.4    Material traceability referred to in section 7.3 of this specification will be applied to all categories of pipe and equipment  and will also include SEP pressure equipment and pipe.

 

B7.       CE MARKING

 

B7.1    After final inspection the purchaser will be responsible for CE marking of the piping systems and/or installation. Contractor shall provide all necessary assistance in terms of documentation and other actions as required by the PED to assist the purchaser in this activity. The following conformity assessment modules will normally be applied:

 

  Category I piping Module A
  Category II piping Module A1
  Category III piping Module B1 + F
  Category IV assemblies Module G

 

Appendix C

 

Recommended Weld Filler Materials, Consumables Control, and Handling

 

 

C1.       PURPOSE

 

C1.1    To define for the contractor (field installation) and supplier (prefabrication) the minimum requirements for receipt, storage, and handling of welding consumables.

 

C2.       related documents

 

C2.1    The American Society of Mechanical Engineers (ASME)

 

SFA-5.1            Specification for Carbon Steel Electrodes for Shielded Metal Arc Welding

SFA-5.4            Specification for Stainless Steel Electrodes for Shielded Metal Arc Welding

SFA-5.5            Specification for Low-Alloy Steel Electrodes for Shielded Metal Arc Welding

SFA-5.9            Specification for Bare Stainless Steel Welding Electrodes and Rods

SFA-5.10          Specification for Bare Aluminium and Aluminium Alloy Welding Electrodes and Rods

SFA-5.11          Specification for Nickel and Nickel-Alloy Welding Electrodes for Shielded Metal Arc Welding

SFA-5.14          Specification for Nickel and Nickel Alloy Bare Welding Electrodes and Rods

SFA-5.18          Specification for Carbon Steel Electrodes and Rods for Gas Shielded Arc Welding

SFA-5.28          Specification for Low-Alloy Steel Electrodes and Rods for Gas Shielded Arc Welding

 

C2.       Definitions

 

C2.1    Coated electrode is a composite filler metal electrode consisting of a core of a bare electrode to which is applied a coating sufficient to produce a metal slag on the welding.

 

C2.2    Consumable is a material employed on the welding protection or deposition (such as electrodes, rods, wire, consumable ring, gas, and flux).

 

C2.3    Critical Service is defined as any piping system in Category M Fluid Service as defined by ASME B31.3 or lethal service defined by ASME BPVC, Section VIII.

 

C2.4    Drying oven is equipment used to dry up the electrodes and fluxes of low hydrogen, which have a controlled heat, through electrical resistances and air renovation, through controlled convection (for example, butterfly valve). It should have at least two instruments of temperature (thermostat and thermometer) as well as shelves with holes or grating type. The drying oven shall have the temperature capacity of 400°C (752°F).

 

C2.5    Drying oven for maintenance is equipment that will attend the same requirements of drying oven operation, except in relation to the temperature, whose capacity must be 200°C (392°F).

 

C2.6    Electrode denotes filler metal in the form of a solid cylindrical rod, typically flue coated.

 

C2.7    Electrode core or bare electrode is a component of a coated electrode.

 

C2.8    Flux is a material used to prevent, dissolve, or ease the removal of oxides and other undesirable superficial substances.

 

C2.9    Quill is a portable drying oven that has heat by way of electric resistance that can follow each welder individually to the welding location. It must maintain the temperature between 60° and 100°C (140° and 212°F).

 

C2.10  Storage oven is a place that has lamps or other forms of heating that allow the goods to be stored in their packing on shelves or crates, whose temperature must be 50°C (90°F) above the room temperature but not less than 20°C (68°F).

 

Note:  The storage oven must have a hygrometer and thermometers to be able to control the humidity and air temperature.

 

C2.11  Welding rod is an electrode used for welding or brazing that does not conduct electricity during the process.

 

C3        Filler Material

 

C3.1    Welding filler metals shall be according to the following:

 

  • For aluminium materials see Appendix D.
  • Consumable inserts shall not be used unless approved by the Purchaser’s representative.
  • Alternate materials may be used on receipt of approval from the Purchaser’s representative.

 

 

Base Metal Bare Wire**** Coated Electrode****
     
CS to CS SFA5.18 ER70S-2 SFA5.1  E6010 (root pass only)
A53 and A106 SFA5.28 ER80S-D2             E7018
     
304 to 304 and 304L SFA5.9  ER308 SFA5.4  E316L-15*
304L to 304L SFA5.9  ER308L SFA5.4  E316L-15*
304 to 316 SFA5.9  ER316 SFA5.4  E316L-15*
316 to 316L SFA5.9  ER316L SFA5.4  E316L-15*
     
316 to 321 SFA5.9  ER347 SFA5.4  E347
321 to 321    
347 to 347    
     
CS to 300 Series SS SFA5.9  ER309 SFA5.4  E309
     
CS to Monel SFA5.14 ERNi-1 (Nickel 61)** SFA5.11 ENiCu-7 (Monel 190)**
     
SS to Monel SFA5.14 ERNiCr-3 (Inconel 82)** SFA5.11   ENiCrFe-3
(Inconel 182)**
     
Monel to Monel SFA5.14 ERNiCu-7 (Monel 60)** SFA5.11 ENiCu-7 (Monel 190)**
     
2 1/4 Cr 1 Mo to    
2 1/4 Cr 1 Mo, or to SFA5.28 ER-90S-B3*** SFA5.5  E9018-B3***
1 1/4 Cr 1/2 Mo    
     
1 1/4 Cr 1/2 Mo to SFA5.28 ER80S-B2*** SFA5.5  E8018-B2***
1 1/4 Cr 1/2 Mo    
     
CS to 2 1/4 Cr 1 Mo SFA5.18 ER90S-B3 SFA5.5  E9018-B3
CS to 1 1/4 Cr 1/2 Mo SFA5.28 ER80S-D2 SFA5.5 E9018-B2
     
Incoloy 800 and 800 H SFA5.14, ERNiCrCoMo-1

(Inconel 617)**

SFA5.11, ENiCrCoMo-1

(Inconel 117)**

Notes:

*       Ferrite Number 3 maximum such as Cryosan E316L-15 by Sandvik Steel or Kryokay E316L-15 by Teledyne McKay, or approved equal when Charpy impact testing is required.

 

**     INCO Brand:  Other manufacturers’ brands are acceptable if they are the same specification/classification.

 

***   The “L” grade for bare wire and coated electrode is also acceptable. All socketwelds shall be dye checked and buttwelds shall be 100% radiographed.

 

**** For materials not listed, the purchaser’s representative must approve the filler metal and procedure to be used.

C4.          Receiving and Inspecting

 

C4.1       Consumables shall be transported to the job site in appropriate conditions, preferably in original sealed containers and protected against humidity.

 

C4.2       The contractor’s welding inspector shall inspect the received consumables and check the following:

 

C4.2.1    Packing shall be received closed and shall not have any defects that would cause contamination and damages to the consumables. It shall indicate without any obliterations and legibly show the trade name, specification, classification American Welding Society (AWS) or ASME BPVC Section II, lot number, and fabrication date.

 

C4.2.2    The coated electrode shall have individual identification of the trade name and/or AWS rating stamped next to the electrode root.

 

C4.2.3    The rods shall have individual identification of the trade name and/or AWS rating stamped either on the material or on small papers/plastic labels located on the end of the material.

 

C4.2.4    Wire spools shall come with identification tags affixed, containing the trade name and AWS rating.

 

C4.2.5    Fluxes shall come in packing (cans, cardboard bags, or plastic) containing the identification without any obliterations, and legible trade name, specification and AWS or ASME BPVC Section II ratings stamped on the package or on the tags attached to the package, as is shown in Figure C1.

 

C4.2.6    Consumables shall be provided with their respective quality certifications, indicating the standard rating required.

 

C4.2.7    Consumables shall not exhibit any signs of oxidation.

 

C4.2.8    Coated electrodes shall not have any defective coatings (for example, thickness reduction, cracks, extremity damages, nonsticking, humidity, or eccentricity).

 

C4.2.9    Rejected consumables shall be segregated and disposed of in a proper and safe manner.

 

C5.          Storage and Control

 

C5.1       Consumables, except gases, after released by the supplier’s or contractor’s certified welding inspector, shall be stored according to requirements based on the AWS rating and its respective run on the ovens, on shelves or crates. Consumables used in critical systems shall be segregated according to purchaser’s requirements.

 

C5.2       Consumables shall be removed from storage through the use of requisitions containing quality, trade name, and/or AWS rating and size.

 

C5.3       The welder storekeeper shall perform the distributions control using the “Electrodes Distribution Control Form” as is shown in Figure C2. Electrodes shall be dispersed to only welders qualified for that particular electrode. The contractor shall have a system to properly identify and verify each welder’s qualifications. Electrodes of specific grade shall not be issued to welders who are not qualified.

 

C5.4       Removal order of consumables from storage shall be done on a first in/first out basis in the order indicated on the receivers.

 

C5.5       Consumables shall be kept in their original packing and opened only before using or drying. Leftover consumables may be returned to stock one time if they are appropriately dried in ovens designated for this purpose. Consumables shall not be returned to stock more than one time.

 

C6.          Drying and Maintenance

 

C6.1       Cellulosic Electrode

 

C6.1.1    According to AWS, cellulosic electrodes are rated as the following:

 

  • AWS E6010
  • AWS E7010-G
  • AWS E7010-A1
  • AWS E8010-G

 

C6.1.2    For this type of electrode it is not necessary to dry. It shall be removed directly from the storage ovens and put in the portable quills that protect against bad weather.

 

C6.1.3    Electrodes not used within the specified time period shall be returned to the storage oven.

 

C6.2       Rutilic Electrodes, Basic and Low Hydrogen

 

C6.2.1    According to the AWS the rutilic electrodes are rated as the following:

 

  • AWS E6013
  • AWS E7014
  • AWS E7024
  • AWS E308-16/E308L-16
  • AWS E316-16/E316L-16
  • AWS E309-16/E309-16
  • AWS E312-16

 

C6.2.2    According to the AWS the basic and low hydrogen electrodes are rated as the following:

 

  • AWS E7018/E-7018-1
  • AWS E7016-1
  • AWS E7018-G
  • AWS E502-15/E-505-15
  • AWS E8018-B2
  • ASW E9018-B3
  • AWS E310-15
  • AWS E318-15/E-308L-15
  • AWS E309-15/E-309L-15

 

C6.2.3    These electrodes must be dried and kept at temperatures according to the tables shown in Table C1.

 

C6.3       Electrodes must be put in the drying ovens on layers no greater than 50 mm (2 in).

 

C6.4       The welder storekeeper shall manage the drying control using the “Electrode Handling Control Form” shown in Figure C3.

 

C6.5       The welder storekeeper shall manage the electrode drying according to the daily-forecasted consumables for the performance and plus 20% after that.

 

C6.6       After drying, electrodes shall be kept in the maintenance ovens on layers not higher than 150 mm (6 in) and 25 mm (1 in) of side gap.

 

C6.7       When not used, electrodes must be kept in portable ovens at a temperature from 60° to 150°C (140° to 302°F).

 

C6.8       Electrodes dried outside the maintenance ovens or that have not been used after their initial work cycle shall be returned and redried. Electrodes that have been redried shall have the ends painted.

 

C6.9       Redried electrodes must be used during their next work cycle. It is prohibited to make a second redrying.

 

C6.10     Wires and Rods

 

C6.10.1  Wires and rods to be used shall be directly removed from the storage place and placed in the appropriate drying oven.

 

C6.10.2  When there are various classes of rods at the storage place, the rods shall be painted at their extremities for better identification.

 

Example:

 

Class AWS Color
ER70S-3 white
ER80S-B2 blue
ER308 green

 

C6.10.3  Wire spools that are used shall be returned to the storage place with their respective plaques or identification tags in place.

 

C6.10.4  Wire spools shall be protected against humidity, dust, and others contaminants when they are outside the storage place.

 

C6.10.5  Rods shall be cleaned immediately before using.

 

C6.11     Fluxes

 

C6.11.1  Drying ovens with trays for drying or flux drying maintenance shall not be layered more than 50 mm (2 in).

 

C6.11.2  After a work cycle flux not used shall be returned to storage. It is prohibited to make a second redrying.

 

C6.12     Drying ovens shall have calibrated thermometers according to industry standards.

 

                                                                      Figure C1                                                       

 

Electrode Distribution

Control Form

Number:

 

Date:

 

Responsible:

 

Customer:                                                              Contract:

 

          Quantity

(kg or piece)

 

Responsible

 

Date

 

Stamp

Consum-able Lot

Number

Diameter

(mm)

 

Taken

 

Time

Turned

Back

 

Time

for Hot Sterilizer
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   

 

(1)     Consumable fabrication date            (6)     Quantity of consumable taken in kg or piece

 

(2)     Qualified welder’s number                (7)     Time at which the consumable is taken

 

(3)     Type of consumable                         (8)     Quantity of consumable turned back in kg or piece

 

(4)     Consumable fabrication lot number  (9)     Time at which the consumable is turned back

 

(5)     Consumable diameter                     (10)    Name of the person responsible for the hot sterilizer

Table C1                                                                

 

Table of the Recommendable Temperatures for Consumable

Storage, Drying, and Drying Maintenance

 

 

Classification

Conditions of

Storage

 

 

 

Drying

A W S Type Before Unpacking Drying Maintenance
E6010

E7010-G

E7010-A1

 

Cellulosic

 

Keep off floor

Not

recommended

Not

recommended

E6013

 

E7024

 

Rutilic

 

Keep off floor

Not

recommended

Not

recommended

E7018

E7016

E7018-1

E8018-G

E8018-B2

E9018-B3

 

Basic

low

hydrogen

 

 

 

Keep off floor

 

300° + 50°F

 

during

1 hour

 

 

700° to 800°F

E502-15

 

E505-15

 

Basic

 

Keep off floor

300° + 50°F

 

during 1 hour

 

700° to 800°F

Examples: E308L

E309L

E316L

 

 

Basic

 

Keep off floor

 

225° – 300°F

 

Per manufacturers recommendations

Examples:

E308-L

E309-L

E316-L

 

 

Basic

 

Keep off floor

 

225° – 300°F

 

Per manufacturers recommendations

FLUX

F-7x

F-8x

 

Basic

 

Keep off floor

500° + 50°F

during

1 hour**

250° to 300°F

above dew point

Rods

Wire

Not

applicable

Keep off floor Not

applicable

Not

applicable

 

 

                                                                                                                Figure C2                                                

Electrode Handling Control Form (Reduced Form)

 

  Customer: Number: Sheet.:
  Contract: Date:  
  Title: Performed By: Approved By:

 

            Drying  
 

Manufacturer

 

Trade Name

Diameter

(mm)

AWS

Specification

 

Lot Number

Quantity

(kg)

Beginning

(time)

Conclusion

(time)

Temperature

(°C)

 

Notes

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   

 

(1)     Consumable manufacturer name                                         (6)     Quantity of consumable received

(2)     Consumable trade name                                                      (7)     Time of the consumable drying beginning

(3)     Consumable diameter                                                          (8)     Time of consumable drying conclusion

(4)     Specification according to AWS standard                              (9)     Drying temperature

(5)     Lot fabrication number of the received consumable           (10)    Field for additional information

 

 

 

Appendix D

 

Aluminium Welding

 

 

D1.      WELD PROCESSES

 

D1.1    Welding shall be performed using the gas tungsten arc welding (GTAW) process (using alternating current exclusively) or the gas metal arc welding (GMAW) process. The GMAW process is recommended for prefabricated heavy wall pipe diameters DN200 (NPS 8) or larger.

 

D1.2    No single pass or filler bead shall be more than 19 mm (3/4 in) in width.

 

D1.3    Only stringer passes are acceptable. Wash-type passes are not acceptable.

 

D2.      WELDING QUALIFICATION REQUIREMENTS

 

D2.1    Refer to Section 8.2 of this specification for welding qualification requirements. In addition, aluminium welders shall be qualified welding Schedule 10 pipe when Schedule 10 is specified. When allowed by code, x-ray shall be used for welder performance qualification.

 

D3.      FILLER MATERIAL

 

D3.1    The types of filler metal per AWS A5.10 (ASME SFA 5.10) to be used for welding various aluminium-alloy pipe combinations are given in the following table:

 

 

Base Metal

Filler Metal

3003 to 3003 ER1100 or ER4043
3003 to 5083 ER5556
3003 to 5086 ER5556
3003 to 5086 (1/2 inch instrument lines only) ER4043
3003 to 6061 ER4043
5083 to 5083 ER5556
5083 to 5086 ER5556
5083 to 6061 ER5556
5086 to 6061 ER5556
6061 to 6061 AWS A5.10 ER5556

 

D3.2    Filler material shall be purchased from Air Products approved suppliers:

 

AlcoTek Wire Corporation

2750 Aero Park Drive

Traverse City, Michigan 49686

USA

 

Metalli Trafilati Laminati srl.

25069 Villa Carcina

Brescia

Via Veneto 30

Italia

 

D4.      CONTROL OF CONSUMABLES

 

D4.1    Refer to Appendix C,  Welding Consumables Storage and Handling.

 

D4.2    Only filler material that can be used within a four-hour period shall be removed from stock.

 

D5.      BACKING RINGS FOR ALUMINIUM WELDS

 

D5.1    All one-sided aluminium butt welds (excluding branches and weldolets) shall include the use of backing rings. Dimensions of backing rings shall be:

 

Pipe Size

DN mm (in NPS)

Ring Dimensions

mm (in)

   
65, 80 (2 1/2, 3) 3    (1/8) thick x 25.5 (1) wide
100, 150, 200 (4, 6, 8) 6.5 (1/4) thick x 25.5 (1) wide
250 (10) and larger 6.5 (1/4) thick x 38 (1 1/2) wide

 

D.5.2   The composition of backing rings shall be:

 

Aluminium Pipe Material Combinations

 

Pipe Material Back-up Ring Material
   
3003 to 3003

3003 to 5083

3003 to 5086

3003 to 6061

               1100 or 3003

3003 or 5083

3003 or 5086 or 5083

3003 or 6061 or 50831

 

5052 to 5052

 

5052 or 50832

5083 to 5083

5083 to 6061

               5083

5083

5086 to 5083                5086 or 5083
5086 to 5086

5086 to 6061

               5086 or 5083

6061 or 5083

6061 to 6061                      6061

1Use 3003 or 6061 back-up ring material when operating or design temperature >66°C (150°F).

 

2Use 5052 back-up ring material when operating or design temperature >66°C (150°F).

 

 

D5.3    Aluminium weld joints that can be welded from both sides do not require backing rings. However, the second side shall be cleaned by back grinding before welding is resumed.

 

D6.      WELD PREPARATION AND FIT UP

 

D6.1    Material removal shall be by filing or routing using suitable cutters. Grinding wheels shall not be used on aluminium material.

 

D6.2    All surfaces to be welded shall be cleaned to remove oil, grease, and dirt. Vapor or solvent degreasing will usually be satisfactory. If heavy oxide is present on the metal surface, the metal surface shall be cleaned by mechanical means (for example, stainless steel wire brushing).

 

D6.3    Immediately before fit up, all fusion surfaces, backing rings, and an area within 10 mm (3/8 in) shall be cleaned free of oxide by scraping or brushing with clean stainless steel wire brushes. Brushes must be kept clean at all times and light pressure should be used in brushing (excessive pressure can cause metal folds to form trapping dirt and oxides and causing unnecessary weld porosity.)

 

D6.4    Each weld pass shall be thoroughly cleaned by using a stainless steel wire brush before completing the succeeding pass.

 

D6.5    Attempts shall be made to complete weld joints upon fit up (within approximately four hours). Fit-up joints shall be covered before welding.

 

D6.6    Weld fit-up and the welding operation must be shielded from atmospheric contamination and humidity. Contractor for field welding shall provide details of proposed sheltering and humidity control in proposal.

 

D7.      WELDER IDENTIFICATION

 

D7.1    Each welder shall identify the welder’s specific production welds by etching the welder’s regularly assigned identification number with an electric pencil or low stress stamps on the pipe adjacent to the welds.

 

D8.      REQUIRED WELDING EQUIPMENT, GAS TUNGSTEN ARC WELDING ALUMINIUM

 

D8.1    Welding Power Supply:  A 300 to 500-ampere Miller Electric Mfg. Co. Synchrowave or equivalent shall be used.

 

D8.2    Welding Torch:  A 350-ampere minimum capacity, water-cooled torch shall be used. It must be capable of accepting 3, 4, and 5 mm (1/8, 5/32, and 3/16 in) diameter electrodes. If welding is to be performed at 250 amperes or above, a 500-ampere, water-cooled torch shall be used. Welding torches shall use a remote contactor switch to make and break the arc and current control (foot pedals are not recommended for field locations).

 

D8.3    Water Cooler:  Radiator or tank-type water coolers shall be used. Alternatively, the welding torch may be connected directly to a house water line and water run continuously while welding. (However if water temperature is cooler than ambient temperature there will be a tendency for torch components to “sweat” when welding is not being done. Minute traces of moisture on aluminium can produce severe weld porosity. Therefore, recirculating units are recommended.)

 

D8.4    Electrodes:  Pure tungsten electrodes or zirconiated electrodes may be used in the following sizes:

 

  • 3 mm (1/8 in) diameter for welding currents less than 125 amperes
  • 4 mm (5/32 in) diameter for welding currents of 100 to 200 amperes
  • 5 mm (3/16 in) diameter for welding currents of 175 to 300 amperes

 

D8.5    Gas Cup Sizes:

 

  • 10 or 8 mm (3/8 or 5/16 in) inner diameter for 3 mm (1/8 in) diameter electrodes.
  • 11 or 10 mm (7/16 or 3/8 in) inner diameter for 4 mm (5/32 in) diameter electrodes.
  • 13 or 11 mm (1/2 or 7/16 in) inner diameter for 5 mm (3/16 in) diameter electrodes.
  • 16 mm (5/8 in) inner diameter for 4 mm (5/32 in) or 5 mm (3/16 in) diameter electrodes preferred for field welding conditions.

 

D8.6    Gas Supply:

 

  • Shielding gas shall be argon or a combination of argon and helium.

 

  • Dew point shall be -76°F (60°C) or less. Argon purity shall be 99.999%. Helium purity shall be 99.995%. Supplier shall provide product purity certificates.

 

  • Care must be taken to ensure that air cannot be aspirated into the gas passages. If the welding system has any leaks, the gas will become contaminated. Shielding gas supply hoses used to connect cylinders to torch shall have minimum number of connections. Use of hoses of Tygon or similar material is prohibited. Supply hoses shall be kept dry. When hoses are not in use, they shall be stored in a dry area. Flowmeters shall be specified to match shielding gas requirements.

 

D8.7    Electrical Characteristics:  All welding shall be performed using alternating current. High frequency or similar arc starting is required. Scratch starting is not allowed.

 

D9.      REQUIRED WELDING EQUIPMENT, GAS METAL ARC WELDING ALUMINIUM

 

D9.1    Welding Power Supply:  A constant, potential power supply of 300 amperes minimum capacity shall be used.

 

D9.2    Wire Feeder and Gun:  The wire feeder must be designed for aluminium welding. The welding gun must be water-cooled.

 

            Note:  For light duty applications requiring no more than 200 amperes, a self-contained, air-cooled feeder/gun (such as the ESAB 1-lb spool gun) may be used.

 

D9.3    Water Cooler:  See paragraph D8.3 for requirements.

 

D9.4    Gas Supply: See paragraph D8.6 for requirements.

 

D9.5    Filler Materials:  Spooled wire (according to ASME SFA-5.10) shall be used.

 

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