1. PURPOSE
1.1 This global specification defines the procedures to be used when receiving, storing, dressing with platforms and ladders, erecting, and leveling shop‑fabricated cold boxes at erection site.
2. scope
2.1 This specification applies to the site erection of all shop-fabricated cold boxes designed, manufactured, supplied, or installed by Air Products Construction Engineering. This procedure does not cover the site fabrication of cold boxes in the vertical position.
2.2 The site specific scope of work specification has precedence over this specification.
2.3 No exceptions shall be permitted without the written approval of the purchaser.
2.4 In the case of conflict between the requirements of this specification and any others, the purchaser’s representative will adjudicate, and his word will be final.
3. related documents
Note: The following documents, by reference, form a part of this specification and refer to the latest edition and addenda in effect at date of manufacture of any item covered by this specification. Any conflicts among the referenced documents not resolved by this specification shall be brought to the immediate attention of Air Products.
3.1 Air Products Engineering Documents 3CS02001 Grouting of Equipment and Structures 4ACS-640106 Grouting of Equipment and Structural Steel 4ACS-640130 Fabrication of Structural Steel 4ACS-640132 Structural Steel Erection 4ACS-640133Anchor Bolt Tensioning Requirements for Equipment and Structural Steel 4ECE-M05 Supply and Fabrication of Structural Steelwork 4ECE-M08 Handling Structural Steelwork on Site 4ECE-M13 Grouting of Equipment and Structures 4WCB-50001 Perlite for Cold Box Insulation 4WCB-50002 Mineral Wool for Cold Box Insulation 4WCE-600276 Packing Process Equipment Jackets with Mineral Wool (Rock Wool) 4WCE-600500 Crane and Lifting Procedures 4WEQ-6804 Painting and Corrosion Protection for Design Temperatures to 649°C (1200°F) 4WMA-007018 Site Plumbness Tolerances for Erected Distillation Columns and Cold Boxes Containing Distillation Columns 4WPI-EW44001 Pressure Testing Process Piping and Equipment
4. DEFINITIONS
4.1 Approved means the described design, item, procedure, or document shall be approved by the purchaser before starting work
4.2 Cold box is a modularized process unit for the cryogenic separation of gases, using equipment and piping preassembled within a structural steel frame that is fully sealed with steel panels.
4.3 Contractor shall mean the company and its subcontractors awarded the work by Purchaser and named in the construction agreement.
4.4 Ground includes soil and improved surfaces such as aggregate paving, asphalt, and concrete.
4.5 Owner is the Air Products company or client as nominated in the purchase order.
4.6 Purchaser shall mean the Purchaser, Joint Venture, Project Company, or Client Company placing the purchase order on the contractor.
4.7 Purchaser’s representative is any qualified Air Products site or plant manager or designated employee who has responsibility for organizing and managing lifting operations in a specific location.
4.8 Shipping and Loading Diagram is the Air Products shipping and handling drawing.
5. COLD BOX EQUIPMENT: GENERAL
5.1 Cold boxes are designed for employment in cryogenic service at temperatures well below the freezing point of water, oils, and other liquids. Certain components within the cold box might contain passages as small as 0.2 mm (0.08 in), and these are extremely susceptible to blockage. For these reasons cold boxes are supplied with process internals cleaned and dried to rigorous standards. It is vital that these standards of cleanliness and dryness are maintained to avoid serious problems during start-up and operation of the plant.
5.2 Cold boxes are shipped to site with piping penetrations protected by caps, blind flanges, or welded plates to maintain a dry, oil-free air or nitrogen purge pressure and prevent the ingress of foreign matter into the systems. These caps, blind flanges, and welded plates must only be removed immediately before connecting internal crossover and external yard piping, and only after safe depressurization of any purge. Typical practice is these removable pieces are painted with Yellow paint indicating removal.
5.3 Cold boxes are designed to be supported on the “shipping side” (that is, front face) only while in the horizontal position. The “shipping side” of the cold box is the side that is resting on the transportation equipment. With the box in the horizontal position, the top of the box is known as the rear face of the box. The orientation and location of the box shall be shown on the plant equipment arrangement drawing. The cold box shall not be rotated on its horizontal axis when in the horizontal position.
5.4 The four sides and top of a cold box might have various sizes of pipes penetrating the skin or shell of the cold box, ranging from DN8 to DN750 (NPS 1/4 to NPS 30). The pipe penetrations will be sealed (made watertight) between the outside diameter of the pipe and the cold box shell. Extreme care shall be exercised to protect these penetrations.
5.5 Cold boxes are typically provided with one pair of lifting lugs or trunnions at the base of the cold box and one or two pairs of lifting lugs or trunnions at the top of the box. The lifting lugs or trunnions shall be used at all times when lifting the box. No lateral loads may be imposed on any cold box lugs or trunnions. Spreader beams must be used at all times. The contractor shall adhere to requirements of the Air Products shipping and handling drawing. Note: In some cases, additional trunnions are provided on the top side of the box for ease when lifting on/off ships. These trunnions shall not be used for raising/lifting the cold box into the vertical position.
5.6 Cold boxes supplied by Air Products will normally have several coats of prime paint and, in most instances, a finish coat. Caution shall be exercised to protect the paint finish. Areas of damage incurred during the execution of this work shall be repaired in accordance with 4WEQ-6804, as appropriate.
5.7 The purchaser’s representative shall be consulted when a cold box is designated as having a “stressed panel cold box design,” or when there is a sign on the side of the cold box indicating such. There are specific entry requirements and procedures that need to be reviewed and implemented before entering or creating accessways into such a cold box structure. The sign or decal on the cold boxes will state:”WARNING: Do not remove or cut into the panels of this cold box without consulting the plant operating manual for specific guidelines and restrictions.”
5.8 Access into any cold box not provided with removable entry panels will be by cut-outs made at site. The advice of the purchaser’s representative shall be sought before making any cuts in the cold box paneling to maintain the structural integrity of the cold box frame and avoid any damage to the box internals.
6. SITE INSPECTION
6.1 After contract award, but before the start of work at site, the job site shall be visited and the civil and mechanical drawings reviewed to determine the site conditions, working and/or lay-down space available, the foundations, and equipment that will be installed, and to inspect access roads and off-loading areas.
7. RECEIPT OF COLD BOX EQUIPMENT AT SITE
7.1 Immediately upon receipt at site and before removal from the transport equipment, cold boxes shall be inspected internally and externally for any signs of damage, including the presence of water (especially sea water). Any such damage shall be reported to the purchaser’s representative immediately. For cold boxes shipped with nitrogen purge, internal inspection shall be performed using confined space entry procedures.
7.2 Cold boxes supplied by Air Products are delivered with the piping systems and equipment under a positive purge pressure. Upon receipt at site and before removal from the transport equipment, the indicated level of pressure shall be checked and verified against the shipping note and general arrangement drawing. If the purge pressure is less than that specified, the purchaser’s representative shall be notified immediately.
7.3 Cold boxes are delivered to site with a number of components packed separately (for example, valve top works, cold box relief valves, and closed cell foam tape). These components are often in separate crates. Upon receipt all loose items shall be checked against the following criteria: State of shipping seal State of cleanliness State of paint work Losses/damage identified and noted on shipping manifest Documentation/certification
7.4 Any nonconformance of the components to specification shall be noted, the material segregated, and the purchaser’s representative informed. After checking as detailed above, loose components shall be kept in a clean, dry, covered area until they are required for installation.
8. OFF-LOADING OF COLD BOX EQUIPMENT
8.1 All external temporary shipping beams shall be removed from transportation trailers or equipment and disposed of as directed by the purchaser’s representative. The bolsters and shipping plates might need to be loaded onto a truck for shipment back to the supplier. This will be at the direction of the purchaser’s representative.
8.2 Off-loading of the cold box shall be accomplished by the use of two cranes using the one set of trunnions at the base of the cold box and the lifting lugs or trunnions on the top of the cold box.
8.3 Off-loaded cold boxes shall be supported with timber cribbing or steel beams (with plywood between the steel beams and cold box face) at the locations specified on the Air Products shipping and handling drawing or as directed by the purchasers’ representative. Supports shall not be placed at any other location. Timber cribbing or steel beams shall be located on a level, well compacted (for example, actual bearing capacity does not exceed allowable ground bearing capacity) and well drained area. Under no circumstances shall cold boxes be laid directly on the ground.
8.4 When a cold box has been unloaded from its transport, it shall be inspected for any signs of damage caused during transport and/or off-loading, including a check of the piping/equipment purge pressure. If any damage is discovered, this shall be reported to the purchaser’s representative immediately.
9. STORAGE OF COLD BOXES AT SITE
9.1 If a cold box is stored at the site before erection, it shall be protected against or kept away from any sources of contamination that might affect the box structure or paint work (for example, salt water, vehicular spray, smokestack emissions, flares, or particles caused by grinding or cutting).
9.2 All necessary precautions shall be taken to protect cold boxes from damage (including that caused by the weather) and to maintain internal cleanliness. Loose items (as described in paragraph 7.3) that are found to have been soiled during storage shall be re-cleaned.
9.3 Each day, a check shall be made of the positive pipe/equipment purge pressure within each cold box. These checks shall be recorded in a daily log noting the pressure of purge, and the purchaser’s representative shall be notified if the level of pressure changes at any time. (Should add a =/- number off gauge pressure or % since pressure will change throughout the day because of ambient temperature changes.)
9.4 At the same time as the daily piping/equipment purge pressure check, a check shall also be made for any damage to the cold boxes. If damage is observed, the purchaser’s representative shall be notified, and no further lifting, transport, or other movement of the cold box will be allowed until authorized by the purchaser’s representative.
10. DRESSING COLD BOXES WITH LADDERS AND PLATFORMS
10.1 When the design of the cold box allows, the box may be dressed with some of the access platforms, ladders and select piping before final erection. Additionally, installation of ship loose items such as valve top works may be installed while cold box is in the horizontal position. When doubt exists as to whether a particular box has been designed to allow this, the guidance of the purchaser’s representative shall be sought and will be explained in the scope of work.
10.2 Cold box platforms and ladders shall be fabricated in accordance with the contract drawings, 4ECE-M05 and 4ACS-640130.
10.3 Cold box platforms and ladders shall be erected in accordance with the contract drawings, 4ECE-M08 and 4ACS-640132.
10.4 When considering the extent to dress out a cold box in the horizontal position before being erected, consideration shall be given to the need to provide clearance for slings, shackles, spreader beams and other lifting equipment items used during the erection of the cold box. Examples of attachments can be platforms, handrails, ladders, piping, pipe supports, or internal valves. The weight of the added pieces shall be listed or itemized to assure that all have been considered and incorporated into the lift plan. Platforms, ladders, valves and piping shall not be mounted when there is the possibility of interference with lifting and rigging equipment.
10.5 If, during the erection of the platforms, any surface damage or discoloration of the paint surface of the cold box or other structural steelwork occurs, this must be repaired in accordance with 4WEQ-6804 and to the satisfaction of the purchaser’s representative.
10.6 Any repair/touch up of damaged or cut galvanised steelwork shall be made in accordance with 4ECE-M05 and 4ACS-640130, and to the satisfaction of the purchaser’s representative.
10.7 When welding galvanized steelwork, all galvanizing must be ground back before welding. The damaged areas must be treated as described in paragraph 10.6.
11. PREPARATION OF COLD BOX EQUIPMENT FOR LIFTING
11.1 After the award of the contract, two copies of the erection procedure shall be submitted to the purchaser’s representative for review and approval. Erection procedures shall conform to the requirements of 4WCE-600500. The erection procedure shall specify whether the cold box will be lifted dressed with platforms and ladders, or whether these will be installed after the lift. The boom clearance drawing shall reflect this.
11.2 All temporary pipe supports fitted inside the cold box for transportation are painted yellow or orange and are listed in the cold box fabrication report, which is prepared by the cold box fabrication shop and issued by Air Products, Inc. Project Engineering. This fabrication report will indicate whether a temporary support can be removed before or after erection. Other temporary supports, braces, bolts and/or shims could be specified on fabrication drawings for transportation. All these components must be removed as well. A summary list of these temporary components is created for use in the field. This list will designate whether these components can be removed before or after erection. There are also other temporary shipping items located on the exterior of the cold box; the removal of these items will be explained further in the scope of work document.
11.3 If a cold box is stored at a different location to the erection area, all dollies, trailers, lowboys, and all other equipment used to transport the equipment from the storage area to the erection area shall be designed for the load and site road and ground conditions. Equipment shall be maintained in first-class working condition. Suitable cribbing shall be used for supporting the cold box on the transport. Location of cribbing shall be as shown on the shipping and handling drawings or as directed by the purchaser’s representative. After placing the cold box on the transport equipment, the cold box shall be lashed to the transport equipment before moving. The lifting lugs, trunnions and/or lashing lugs (that is, D-rings) may be used for lashing the cold box to the transport equipment using alloy chain, wire rope, and/or slings. The contractor or transport company shall consult the purchaser’s representative if additional supports or “D” rings need to be welded to the cold box. Cushioning material must be placed at all lashing locations that wrap around the front face chord of the cold box. The size and weight of the cold box shall determine the size and number of securing chains, wire ropes, and/or slings to be used. The minimum acceptable number of securing chains, wire ropes, and/or slings shall be four—two at each end of the cold box.
11.4 When the external surfaces of a cold box are found to be dirty, the purchaser’s representative shall be consulted as to the need to wash the box while in the horizontal position, immediately before erection.
12. COLD BOX ERECTION
12.1 Before the commencement of the erection work, a detailed survey/inspection of the location, size, and elevation of all foundations, holes, and anchor bolts, and their alignment, shall be conducted by this contractor. Any discrepancies between as built conditions and contract drawings shall be reported immediately to the purchaser’s representative.
12.2 Shims shall be used under baseplates as required to set the equipment at the correct elevation and for plumbing. Shim material will be as specified on the contract drawings. The concrete surface of the foundation shall be scabbled/roughened to provide a good key for grouting. Shims shall be placed 13 to 19 mm (1/2 to 3/4 in) inside the equipment perimeter. Shims shall be sized for loading not to exceed 211 kg/cm2 (3,000 psi) on the concrete foundation.
12.3 In addition to the requirements of paragraph 7.3, 8.4, and 9.4, the piping/equipment purge pressure shall be checked and recorded before and after lifting each cold box into position. If purge pressure is lost during the lifting operation, the purchaser’s representative must be informed immediately. No further lifting, transport, or other movement of the cold box will be permitted until authorized by the purchaser’s representative.
12.4 All lifting shall be performed in accordance with specification 4WCE-600500 and the contract drawings.
12.5 Only trunnions/lifting lugs, as indicated on the shipping and handling drawings, shall be used for lifting the cold box. Spreader beams must always be used when called for on the shipping and handling drawings. Contractor is permitted to grease or lubricate the trunnions to allow for easy movement of the sling around the trunnions to prevent jerking or load shock of the box while being raised into the vertical position.
12.6 Extreme care must be taken to protect all pipe and valve penetrations on the sides and top of each cold box during erection.
12.7 When the cold box has been supplied with external shipping beams, they shall be unbolted from the connection end plate after the weight of the box is taken by the main and helper cranes, but before lifting has commenced. The shipping beam connection end plates must be removed by grinding only. Removal by torch is not permitted. Cold box paint work shall then be touched up as required.
12.8 Some cold boxes require the installation of anchor bolt chairs or hold-down lugs. The chairs must be welded to the box and dye penetrants tested after the welds have been completed. The erecting contractor shall ensure that the chairs/lugs will not interfere with the installation of the anchor bolt nuts; this shall be confirmed before the erection activity starts. Contractor must ensure that the box is vertically plumbed before welding. The contractor must properly prepare the surface where the anchor chairs/lugs attach to the cold box frame, it is best to do this before the lifting activity begins while in the horizontal position.
13. COLD BOX LINING AND LEVELING
13.1 All cold boxes shall be set plumb, level, and true in elevation and orientation as shown on the contract drawings and shall satisfy the requirements of 4WMA-007018, the other referenced specifications, and the best industry practices.
13.2 Cold boxes may be fitted with either plumb line lugs or “bull’s-eye” targets for use in lining and leveling. The actual arrangement will be as specified in the contract drawings. There may be times where the sun creates expansion of the box; this shall be brought to the attention of the purchaser’s representative.
13.3 When plumb line lugs are employed, cold boxes might be fitted with one or two pairs of lugs. Lug locations will be detailed in the contract drawings. Before erecting the box vertically, piano wire shall be stretched between the lugs.
13.4 The column vertical alignment shall be checked using a theodolite to view the plumb line or lines. The maximum vertical misalignment of the plumb lines shall be in accordance with the requirements of 4WMA-007018, Section 6.
Note: For cold boxes with two plumb lines, the direction of sighting each line is important as they are only set plumb in one plane.
13.5 Cold boxes might be supplied with “bull’s-eyes” fitted in place of plumb line lugs. For alignment, these cold boxes shall be treated as site-erected columns in accordance with the requirements of 4WMA-007018, Section 5. One pair of the decals will be attached near the top of the box, while the other pair will be attached near the bottom of the box. The two bull’s-eyes forming a pair will be orientated at 90 degrees apart from each other.
13.6 The box vertical alignment shall be checked using a theodolite to view each pair of “bull’s-eye” decals in turn. The maximum vertical misalignment of the bull’s-eyes shall be in accordance with the requirements of 4WMA-007018, Section 5.
13.7 Cold boxes might be supplied with neither plumb line lugs nor “bull’s-eye” decals. The outside edge of these boxes’ left front tubular steel columns shall be used for plumbing the box. The cold box shall be erected plumb to within 7 mm (1/4 in) maximum vertical misalignment from top to bottom of this structural member, using theodolites set 90 degrees apart.
13.8 Some columns installed within cold boxes might be fitted with top head leveling bosses. These are rarely fitted to new columns because they are not considered an accurate method of setting the column plumb. However, they are occasionally fitted on “exact” repeat columns. If fitted, they shall not be used for cold box lining and leveling.
13.9 The main crane shall be used to lift the cold box for plumbing and shim adjustment and shall not be cut loose from the box until after the vertical alignment has been checked and accepted by the purchaser’s representative, tie-down lugs (that is, anchor bolt chairs) are welded to the cold box (when shipped loose), anchor bolt washers/nuts are in place, and anchor bolts are tensioned per 4ACS-640133 or the contract drawings.
13.10 The cold box vertical alignment shall be checked by either the purchaser’s representative (if experienced in measuring vertical alignment) or by an independent surveyor after leveling is complete. All measurements made in connection with this check shall be recorded by the purchaser’s representative and forwarded to the purchaser’s vessel engineer for review. The records will be retained by the purchaser.
13.11 In certain circumstances it might be necessary to weld the box to baseplates cast into the foundation. This will be specified on the contract drawings, as required.
14. GROUTING
14.1 Grouting shall be completed in accordance with the requirements of 4ECE-M13, 4ACS-640106, 3CS02001, and contract drawings.
14.2 Contactor must ensure that the concrete under the base frame steel is properly prepared for grout. This shall be performed before any lifting activity. It is acceptable to use sacrificial forms under the box frame for grouting and to be used as a backing for the placement of the grout.
15. POST-ERECTION ACTIVITIES
15.1 After erection of a cold box, various items shipped loose need to be installed. Details will be listed in the cold box fabrication report and in accordance with the following paragraphs: The manual and control valve top works and instrument isolation root valves that are shipped loose shall be fitted in accordance with the relevant cold box penetration drawings and yard area equipment “trim” isometric drawings. Valve top works will have been “match marked” in the fabrication shop before removal. The marks shall be checked to ensure that the top works are refitted in the correct orientation. Some control valve actuators have supports from the face of the cold box, which shall be fitted after erection of the box. These are detailed on the pipe support and isometric drawings. When spring supports are installed, these shall be adjusted and have their locking pins removed after any insulation packing has taken place. When Samson valves are to be installed, contractor shall consult the Samson valve installation instructions or Samson representative to witness. Cold box relief valves will be shipped loose with the valve top works. The valves shall be checked and any shipping restraint removed before installation in accordance with the penetration drawings, once the cold box has been erected. All temporary supports shall be removed before installing insulation in the cold box. To confirm completion, each support removed shall be kept for inspection by the purchaser’s representative, and a written record of the supports removed shall also be maintained.
15.2 When plate fin heat exchanger units are included within a cold box, there will be a number of plugs fitted that shall be removed immediately before the installation of insulation. The location of the plugs and the manner in which they are identified are detailed on the plate fin heat exchanger drawings and in the cold box fabrication report. These plugs typically come with paper tags attached to them indicating they need to be removed. The plugs will usually be of a bright colored plastic or identified by a card tag for visibility. After removing each plug, the resulting threaded hole shall be plugged by packing with a small quantity of rock wool fiber.
15.3 Each cold box will be delivered to site with all piping systems fully pressure tested. When local requirements dictate that the piping systems within a cold box must be retested after erection, this shall be performed in accordance with 4WPI-EW44001. When a retest is necessary, a full pressure test procedure shall be submitted to the purchaser’s representative for written approval before commencement of work. This procedure shall positively address the steps to be taken to ensure the prevention of contamination of the piping systems within the cold box during testing.
15.4 Cold boxes and other structures that are insulated with perlite shall be insulated in accordance with 4WCB-50001. Cold boxes and other structures that are insulated with mineral wool, including valve cages or other volumes within perlite-filled boxes, shall be insulated in accordance with 4WCE-600276 and 4WCB-50002.
15.5 The colds box shall be connected to the ground grid once it is set to prevent damage from electrical storms or lightning. This shall be performed as soon as possible.
16. INSTALLATION OF ACCESS HOLES
16.1 The contractor shall consult the Air Products representative when a cold box is designated as having a “Stressed Panel Cold Box Design” or when there is a sign on the side of the cold box indicating as such. There are specific entry requirements and procedures that need to be reviewed and implemented before entering or creating accessways into a cold box structure.