Table of Contents
Section Title Page
| Purpose | 2 | |
| Scope | 2 | |
| Related Documents | 2 | |
| Materials | 3 | |
| Equipment | 3 | |
| Foundations | 3 | |
| Lines, Grades, and Measurements | 3 | |
| Nonmetallic Pipe Storage and Handling | 3 | |
| Pipe Installation – General – All Nonmetallic Pipe | 4 | |
| Underground Installation Procedures for CPVC Solvent-Welded Pipe | 5 | |
| Installation Procedures for Underground Heat Fusion Welded Pipe | 6 | |
| Excavation and Backfill | 6 | |
| Qualifications Required for Joining Procedures | 7 | |
| Joining Method and Procedures | 7 | |
| Butt Heat Fusion of HDPE Pipe | 7 | |
| Solvent Welding Instructions for CPVC Pressure Pipe Systems | 7 | |
| Threaded Joints | 9 | |
| Flanged Joints | 10 | |
| Cleaning | 10 | |
| Inspection, Examination, and Testing | 11 | |
| Pressure Testing | 11 | |
| Disinfection of Potable Water System | 12 | |
| Miscellaneous | 12 | |
| Patching, Replacement, and Modification of Existing Work | 12 | |
| Highway and Railroad Crossings | 13 | |
| Torque Table | 10 | |
| Casing Size and Wall Thickness | 14 | |
| Casing Details – Crossing Under Road or Railway | 14 | |
| Miscellaneous Materials | 15 |
1. PURPOSE
1.1 This specification defines for the contractor the requirements for fabricating and installing nonmetallic underground pressurized piping.
1.2 Refer to 670.221 for fabrication and installation of metallic systems.
2. SCOPE
2.1 This specification applies to all pressurized underground nonmetallic process, potable, utility, and firewater piping systems within the designated battery limits of a facility.
2.2 This specification is not complete without 4WCE-670200, Fabrication and Erection of Process Piping
2.3 The scope of work required by the contractor includes (but is not limited to) fabricating, cleaning, testing, as well as furnishing and installing all pipe, pipe fittings, coatings, valves, gaskets, bolts and nuts, and valve packing as required for the complete installation of pressurized underground piping systems. Fabrication and inspection of all piping shall be per ASME B31.3, except as modified herein.
3. RELATED DOCUMENTS
3.1 Air Products Engineering Documents
4ACS-640101 Reinforcing Steel
4ACS-640102 Concrete Work
4WEQ-6804 Painting and Corrosion Protection of New Construction for Design Temperature to 649°C (1200°F)
4WCE-670200 Fabrication and Erection of Process Piping
4WPI-EW44001 Pressure Testing of Process Piping and Equipment
QC-200A Pressure Test Procedure (Form)
326263A Standard Underground Piping Details – Firewater
3.2 The American Society of Mechanical Engineers (ASME)
B1.20.1 Pipe Threads, General Purpose (Inch)
B16.5 Pipe Flanges and Flanged Fittings
B31.3 Process Piping
3.3 American Water Works Association (AWWA)
C651 Disinfecting Water Mains
3.4 American Society for Testing and Materials (ASTM)
D2774 Standard Practice for Underground Installation of Thermoplastic Pressure Piping
F439 Standard Specification for CPVC Plastic Pipe Fittings, Schedule 80
3.5 Chemtrol – A Division of NIBCO Inc.
Thermoplastic Piping Technical Manual
3.6 State and Local codes
3.7 All codes, standards, and specifications shall be the edition in force at the time the contract is awarded.
4. MATERIALS
4.1 All material, when specified herein or on the contract drawings, shall be of first-class quality, free from defects and imperfections, of recent manufacture, unused, of the classification and grade specified and shall comply with these specifications and Air Products engineering standards.
4.2 This specification contains installation information for the following pipe materials:
Chlorinated polyvinyl chloride (CPVC)
High Density Polyethylene (HDPE)
4.3 Refer to Appendix 1 for acceptable miscellaneous material descriptions.
5. EQUIPMENT
5.1 Refer to Standard Underground Piping Details 326263A for requirements of the following firewater equipment:
| Valves | Hydrant Monitors |
| Valves for Deck Pipes | Tools |
| Valve Boxes and Wrenches | Hose |
| Service Boxes and Key Stops | Hose Reels |
| Hydrants | Hose Reel Nozzles |
| Monitor Nozzles | Hose Reel Covers |
6. FOUNDATIONS
6.1 Foundations, as shown on the contract drawings, shall be constructed in accordance with 4ACS-640101 and 4ACS-640102.
7. LINES, GRADES, AND MEASUREMENTS
7.1 The contractor shall lay out the work and establish elevations and grades in accordance with the contract drawings. The contractor shall verify all dimensions by actual measurement at the site and shall refer any differences between the information on the drawings and existing conditions to the Air Products representative for resolution.
8. NONmETALLIC PIPE STORAGE AND HANDLING
8.1 Storage
8.1.1 Pipe
8.1.1.1 When pipe is received in standard lifts, it shall remain in the lift until ready for use. Lifts shall not be stacked more than three high and shall always be stacked wood on wood.
8.1.1.2 Loose pipe shall be stored on racks with a minimum support spacing of three feet to avoid crushing or piercing.
8.1.1.3 When exposed to high ambient temperatures either while being stored or installed outside, pipe shall be shaded but not covered directly in accordance with manufacturer’s recommendations. This will provide for free circulation of air and reduce the heat buildup due to direct sunlight exposure. Protect pipe from ultraviolet rays, excessive heat, or harmful chemicals.
8.1.2 Fittings
8.1.2.1 Fittings shall be stored in their original cartons to keep them free of dirt and reduce the possibility of damage. If possible, fittings shall be stored indoors.
8.1.3 Solvent Cements and Primers
8.1.3.1 Solvent cements have a definite shelf life and each can and carton shall be clearly marked with the date of manufacture. Stock shall be rotated to ensure that the oldest material is used first. Primers do not have a shelf life but it is good practice to also rotate this stock. Solvent cements and primers shall be stored in a relatively cool shelter away from direct sun exposure.
CAUTION- Solvent cements and primers are composed of various solvents and, as such, require special conditions for storage. Because of their flammability, they must be stored in an area where they will not be exposed to ignition, heat, sparks, or open flames.
8.2 Handling
8.2.1 Pipe and Fittings
8.2.1.1 Care shall be exercised to avoid rough handling of thermoplastic pipe and fittings. They shall not be dragged over sharp projections, dropped, or have objects dropped upon them. Transportation by truck or pipe trailer will require that the pipe be continuously supported. All sharp edges on the trailer bed that could come in contact with the pipe must be padded.
8.2.2 Solvent Cements and Primers
8.2.2.1 Keep containers for solvent cements tightly closed except when in use. Avoid prolonged breathing of solvent vapors. When pipe and fittings are being joined in partially enclosed areas, use a ventilating device to attenuate vapor levels. Keep solvent cements, primers, and cleaners away from all sources of ignition, heat, sparks, and open flames. Avoid repeated contact with the skin by wearing proper gloves (impervious to the solvents). Application of the solvents or cements with rags and bare hands is not recommended; natural fiber brushes and other suitable applicators can produce satisfactory results.
9. PIPE INSTALLATION – GENERAL – ALL NONMETALLIC PIPE
9.1 The contractor shall install piping in accordance with the contract drawings and these specifications.
9.2 Installation shall be as specified by the manufacturer’s specific instructions. Specialized joining equipment shall be as recommended by the pipe and fitting manufacturer.
9.3 All pipe and fittings shall be clearly marked with the manufacturer’s name or trademark, size, schedule (SDR as defined in manufacturer’s catalog), material, applicable ASTM designation, country of manufacture, and the Factory Mutual certification logo, as required.
9.4 The open ends of all pipe fittings and valves shall be kept capped, plugged, or covered until final connections are made.
9.5 Before installation, all lengths of nonmetallic pipe and fittings shall be thoroughly inspected for cracks, cuts, scratches, gouges, buckling, kinking and any other imperfections (such as splits on inside diameter or ends of pipe due to impact) which may have been imparted to the pipe during shipping, unloading, storing, and stringing. Any pipe or precoupled fittings containing harmful or even questionable defects shall be removed by cutting out the damaged section as a complete cylinder.
9.6 During pipe lowering operations, care shall be taken to avoid imposing strains that will overstress or buckle the piping or impose excessive stress on the joints. When lifting fused sections of pipe, chains or cable-type chokers shall be avoided. Nylon slings are preferred. Spreader bars shall be used when lifting long, fused sections. Care shall be exercised to avoid cutting or gouging the pipe.
9.7 The use of sheepsfoot rollers is prohibited when compacting backfill for any nonmetallic underground pipe.
9.8 Pressure testing shall be done only after the manufacturer’s recommended curing time or cooling time has elapsed. See Section 21 for pressure testing instructions.
9.9 Bending of Plastic Pipe
9.9.1 Changes in direction shall be made with suitable fittings. Bending of plastic pipe is not permitted without approval of the Air Products Representative, and only to the minimum radius recommended by the manufacturer for the kind, type, grade, wall thickness, and diameter of a specified pipe.
9.10 Pipe Location
9.10.1 Locator Wire
The location of all pipelines shall be accurately and precisely recorded. All nonmetallic pipe installations shall be traced with a locator wire. The wire shall be minimum 3 mm (1/8 in) galvanized steel wire or #8 copper wire, either bare or insulated. During backfilling, when the fill has been compacted up to the pipe centerline, the wire shall be laid a minimum of 25 mm (1 in) away from the side of the pipe along the entire length.
10. UNDERGROUND INSTALLATION PROCEDURES FOR CPVC SOLVENT-WELDED PIPE
10.1 The general installation procedures detailed here apply to CPVC pressure pipe that has solvent‑welded joints. These procedures are applicable for all liquids that are conveyed at pressures up to the maximum hydrostatic pressure rating of the pipe or of any component in the piping system, whichever is lowest.
10.2 The manufacturer shall be consulted for installation guidance and recommendations on installation of CPVC pipe. Pipe installation shall generally follow procedures referred to in
ASTM D2774.
10.3 Snaking and Overlapping of Pipe
10.3.1 After the CPVC pipe has been solvent welded, it is advisable to snake the pipe beside the trench during its required drying time in accordance with the manufacturer’s recommendations. Be especially careful not to apply any stress that will disturb the undried joint. This snaking is necessary to allow for any anticipated thermal contraction that will take place in the newly joined pipeline.
10.3.2 Snaking is particularly necessary on the lengths that have been solvent welded during the late afternoon of a hot summer day, because drying time will extend through the cool of the night when thermal contraction of the pipe could stress the joints to the point of pull‑out. This snaking is especially necessary with pipe that is laid in trenches (necessitating wider trenches than recommended) and is backfilled with cool earth before the joints are thoroughly dry.
10.3.3 Sections of CPVC pipe that have been backfilled or plowed in during the heat of the day shall be sufficiently overlapped to allow for contraction and not joined up to one another or any stable connection or fitting until the morning following their night of cooling and thermal contraction.
11. INSTALLATION PROCEDURES FOR UNDERGROUND HEAT FUSION WELDED PIPE
11.1 High Density Polyethylene Butt Welded Pipe
11.1.1 Materials, excavation, and installation techniques shall be in accordance with manufacturer’s recommendations and this specification. A totally fusion welded system is required. For butt fusion of pipe to fittings having unequal wall thicknesses, the maximum allowable mismatch shall be limited to one SDR (standard dimension ratio shown in manufacturer’s catalog). If the mismatch exceeds this ratio, then the ID of the thicker component shall be taper-bored with a 15 degree bevel to a land that matches the wall thickness of the thinner component.
11.1.2 Sections of polyethylene pipe shall be joined into continuous lengths on the job site above ground. The joining method shall be the butt fusion method and shall be performed in strict accordance with the pipe manufacturer’s recommendations.
11.1.3 The strength of a fusion weld develops as it cools. Allow ample time for the weld to cool prior to handling or the pressure test.
12. EXCAVATION AND BACKFILL
12.1 Excavation
12.1.1 The contractor shall excavate whatever substance is encountered for all piping, manholes, pits, foundations, and other underground work. Trenches shall be of sufficient width for installation and inspection of pipe in accordance with recommendations of the pipe manufacturer. The bottom of the trench shall be trimmed so that the lower portion of pipe is continuously supported on undisturbed soil until the slope of pipe is uniform between established elevations. If rock or shale is encountered, a sand cushion shall be provided. The cushion shall continuously support the lower half of the pipe circumference. Blocking shall not be used to change pipe grade or to intermittently support pipe across excavated sections.
12.1.2 The depth of the piping for the various underground lines shall not be less than that shown on the contract drawings.
12.1.3 Bedding and backfill shall be in accordance with ASTM D2774 and manufacturer’s recommendations.
12.2 Backfilling
12.2.1 Ideally, for CPVC solvent welded pipe, backfilling shall only be done early in the morning during hot weather when the line is fully contracted and there is no chance of insufficiently dried joints being subject to contraction stresses. After the pipe joints have properly cooled and cured and pipe sections have been tested, inspected, and approved by the Air Products representative, the excavation shall be cleaned of trash and debris. Rocks or stones shall not be dumped directly upon the pipe when backfilling. The backfilling material shall consist of excavation or borrow of sand or gravel. Backfill shall be placed in layers not to exceed 225 mm (9 in) thickness and properly moistened to approximate optimum requirements. Best results are obtained when the soils are in nearly saturated condition. Care shall be taken to avoid floating the pipe. Each layer shall be compacted by hand or vibratory tampers, or by other suitable means, to a density that will prevent excessive shrinkage or settlement. The backfill shall be brought to a suitable elevation above grade to provide for anticipated settlement or shrinkage. Excess excavated material shall be disposed of on the site as directed.
12.2.2 Backfill shall be placed around manholes, pits, and other work. This shall be clean subsoil material placed in 225 mm (9 in) layers. Each layer shall be thoroughly compacted.
12.2.3 Cinders shall not be used for backfill.
13. QUALIFICATIONS REQUIRED FOR JOINING PROCEDURES
13.1 Installation shall be by people certified in the handling and fusing of the specified piping system.
13.2 Training and certification shall be by the manufacturer or an authorized dealer or distributor. Certification shall be within six months of the date of installation.
13.3 The installer shall meet all state and local agency requirements for the installation of the material.
14. JOINING METHOD AND PROCEDURES
14.1 The allowable joining methods for the listed materials are as follows:
14.1.1 Chlorinated Polyvinyl Chloride (CPVC): Use Solvent Weld or Flanges
14.1.2 High Density Polyethylene (HDPE): Use Butt Heat Fusion or Flanges
15. BUTT HEAT FUSION OF HDPE PIPE
15.1 Butt fusion of polyethylene pipe shall be performed in strict accordance with the manufacturer’s recommendations, using equipment which is capable of meeting all conditions recommended by the pipe manufacturer including, but not limited to, fusion temperature, alignment, and fusion pressure.
16. SOLVENT WELDING INSTRUCTIONS FOR CPVC PRESSURE PIPE SYSTEMS
16.1 General
16.1.1 Solvent welding shall be done in strict accordance with manufacturer’s recommended procedures. See Chemtrol Thermoplastic Piping Technical Manual for installation procedures for chlorinated polyvinyl chloride (CPVC) pressure piping systems. Belled-end pipe can also be joined in this manner. CHEMTROL’S TECHNICAL SERVICE is available for additional solvent welding guidance and recommendations.
16.1.2 Do Not Take Shortcuts. Follow Instructions Completely.
16.2 Types of Cement and Primer
16.2.1 All of the products used shall be listed by IAPMO (International Association of Plumbing and Mechanical Officials) for pressure and drainage applications, and shall be NSF (National Sanitary Foundation) approved for potable water. All products used shall also be approved by the pipe manufacturer, such as the following:
Chemtrol Heavy‑Duty Light Gray Industrial‑Grade CPVC Solvent Cement may be used with all sizes of Schedule 40 and 80 CPVC piping. It may be used in any industrial or commercial applications suitable to CPVC. (Orange container label.)
Chemtrol Purple Primer may be used with all CPVC piping applications. (Purple container label.)
16.3 Preparation for Joining
16.3.1 Cutting
16.3.1.1 The smaller sizes of plastic pipe can be cut with a pipe or tubing cutter which has a cutting wheel specifically designed for plastic. The pipe can also be cut with a power or handsaw. A circumferential speed of about 30 m/s (6,000 feet per minute) is suitable for circular saws. Band saw speed shall be approximately 15 m/s (3,000 feet per minute). To ensure square‑end cuts, a miter box, hold-down, or jig shall be used. For best results, use a fine-toothed blade [6–7 teeth per cm (16–18 teeth per inch)] with little or no set [.584 mm (0.023 in) maximum]. If a large quantity of pipe is to be cut, use carbide-tipped blades.
16.3.2 Deburring and Beveling
16.3.2.1 All burrs, chips, and filings shall be removed from both the pipe inside diameter and outside diameter before joining. Use a deburring tool, knife, or a half-round coarse file to remove all burrs.
16.3.2.2 All pipe ends shall be beveled to the dimensions specified by the manufacturer for ease of socketing and to minimize the chances of wiping the solvent cement from the inside diameter of the fitting as the pipe is socketed. The beveling can be done with a coarse file or a beveling tool.
16.3.3 Fitting Preparation
16.3.3.1 Before solvent welding, all fittings and couplings shall be removed from their cartons and exposed for at least one hour to the same temperature conditions as the pipe to ensure that they are thermally balanced before joining.
16.3.4 Cleaning in Preparation for Joining
16.3.4.1 Using a clean, dry, cotton rag, wipe away all loose dirt and moisture from the inside diameter and outside diameter of the pipe end and the inside diameter of the fitting. DO NOT ATTEMPT TO SOLVENT-WELD WET SURFACES.
DANGER – Solvent cements and primers are extremely flammable and produce harmful vapors. Keep them away from heat, sparks, and open flame. Use only with adequate ventilation.
Harmful if swallowed. Avoid prolonged breathing of vapor. Avoid contact with eyes, skin, and clothing. Causes eye irritation. Repeated or prolonged skin contact causes skin irritation. Close container after each use.
FIRST AID
In case of skin contact, flush with water; for eyes, flush with water for at least 15 minutes and seek medical attention. Wash contaminated clothing before reuse. If swallowed, DO NOT INDUCE VOMITING; call a physician immediately.
16.4 Joining
16.4.1 The joining process includes priming, solvent cement application, insertion of pipe into adjacent socket, and removal of excess cement. Follow manufacturer’s instructions for joining the pipe.
16.5 Joint Integrity
16.5.1 CPVC piping joint integrity depends greatly upon following exactly the manufacturer’s instructions regarding specific handling, inspection, storage, shipping, fabrication, installation, testing, and operating instructions. The contractor shall obtain from the manufacturer the product and environmental conditions that go into determining the length of joint drying times before it may be moved and handled and the drying times after which pressure testing may be done.
16.6 DO’S AND DON’TS
16.6.1 DO THIS:
Use the proper applicator (see chart for specific recommendations).
Use the proper type of solvent cement for the job.
Apply the cement while the primer is still wet.
Follow the instructions completely.
16.6.2 DON’T DO THIS:
Don’t attempt to solvent‑weld under the following conditions:
If it is raining
If atmospheric temperature is below 4°C (40F)
If directly exposed to sun at atmospheric temperature above 90°F
Don’t discard empty cans of solvent, primer, or rags in trench or near piping.
Concentrated fumes of dripping cement or primer can cause piping failure.
16.7 Hot Weather Cementing
16.7.1 Since cement contains a solvent, certain precautions or steps shall be taken when the atmospheric temperature is above 32C (90°F) to avoid excessive evaporation of the solvent from the cement just before joining. Such evaporation will cause the cement to prematurely set before joining, thus adversely affecting the joint integrity. Follow the manufacturer’s recommendations for hot weather cementing procedures.
16.8 Cold Weather Cementing
16.8.1 Because the solvents in the cement will not evaporate as readily when the temperature is below 4°C (40F), the pipe joints will not set up as rapidly in cold weather. If solvent‑cementing must be done when the temperature is below 4°C (40F) follow the manufacturer’s recommendations.
CAUTION
DO NOT ATTEMPT TO SPEED THE SETTING OR DRYING OF THE CEMENT BY APPLYING DIRECT HEAT TO THE SOLVENT‑WELDED JOINT. Forced rapid drying by heating will cause the cement solvents to boil off, forming porosity, bubbles, and blisters in the cement film.
16.8.2 Handling of Primer and Cement
16.8.2.1 Observe the “use prior to” date. Cement has a limited shelf life. Do not permit a solvent cement can to stand open. Do not use cement that has dried to the point at which it becomes lumpy and stringy. Throw it away. Do not attempt to thin out sluggish cement with thinner or primer.
17. THREADED JOINTS
17.1 Threading of piping is not permitted in underground plastic pipe.
18. FLANGED JOINTS
18.1 When it is necessary to bolt plastic and metal flanges, use flat‑face metal flanges (not raised face) and use recommended torques shown in Table 1.
18.2 Dimensions
18.2.1 Bolt circle and number of bolt holes for the flanges are the same as Class 150 metal flanges per ASME B16.5. Threads are tapered, iron pipe‑size threads per ASME B1.20.1. The socket dimensions conform to ASTM F439 for Schedule 80 CPVC which gives dimensional data for 13 through 150 mm (1/2 through 6 in) nominal. Internal Chemtrol specifications have been established for the eight-inch CPVC design.
18.2.2 Installation Tips (The method for joining two flanges together.)
18.2.2.1 Make sure that all the bolt holes of the mating flanges match up. It is not advisable to twist the flanges to achieve this.
18.2.2.2 Use flat washers under bolt heads and nuts.
18.2.2.3 Insert all bolts. (Lubricate bolts.)
18.2.2.4 Make sure that the faces of the flanges mate snugly and are not drawn together by the bolts.
18.2.2.5 The following tightening pattern is suggested for the flange bolts:
The bolts on the plastic flanges shall be tightened by pulling down the nuts diametrically opposite each other using a torque wrench. Complete tightening shall be accomplished in stages. The final torque values are shown in Table 1. Uniform stress across the flange will prevent leaky gaskets.
18.2.2.6 If the flange is mated to a rigid and stationary flanged object or to a metal flange, the adjacent plastic pipe must be supported or anchored to eliminate excessive stress on the flange joint.
Table 1 – Torque Table
| Flange Size | Recommended Torque* | |
| mm | Inches | Foot Pounds |
| 13–38 | 1/2–1 1/2 | 10 15 |
| 50–100 | 2–4 | 20 30 |
| 150–200 | 6–8 | 33 50 |
| 250 | 10 | 53 75 |
| 300 | 12 | 80 110 |
*For a well-lubricated bolt with flat washers under bolt head and nut.
19. CLEANING
19.1 All pipe and fittings shall be cleaned to the level specified in the contract drawings. Care shall be taken to use methods which are not harmful to the pipe materials.
20. INSPECTION, EXAMINATION, AND TESTING
20.1 Inspection, examination, and testing shall be in accordance with ASME B31.3, Part 10, paragraphs A340 through A346 for nonmetallic piping, and the procedures set forth in the engineering design.
21. PRESSURE TESTING
21.1 Testing shall be done as directed by the Air Products field representative in accordance with 4WPI-EW44001. Hydrostatic testing (not pneumatic) shall be done for all systems unless otherwise specified in the engineering design.
21.2 Tests are to be conducted for tightness of lines and joints, valve bonnets, valve packing, and other fittings. Refer to 4WPI-EW44001 and QC200B (part of 4WPI-EW44001) for testing media and test pressures. See paragraph 21.6 of this specification for pressure testing of fire protection systems.
21.3 All tests shall be performed in the presence of and to the satisfaction of the Air Products representative. The contractor shall notify the Air Products representative in advance of any test performance.
21.4 Due regard for safety shall be constantly observed.
21.5 Special Requirements for CPCV Pressure Testing
21.5.1 Initial Joint Testing: Initial joint testing of CPVC pipe shall be done by introducing ten percent of its hydrostatic pressure rating after the drying times furnished by the manufacturer.
21.5.2 High Pressure Testing: The CPVC pipe can be pressure tested up to 100 percent of its hydrostatic pressure rating after the drying times furnished by the manufacturer.
21.5.3 Full Time Working Pressure: CPVC joints may be introduced to maximum working pressure on a full-time basis after the drying time furnished by the manufacturer.
21.6 Pressure Testing Fire Protection Systems
21.6.1 Prior to obtaining final approval of the fire protection system by the local and/or state inspector, the contractor shall furnish a written statement, countersigned by the Air Products representative, to the effect that the work has been completed in accordance with the approved specifications and plans. Tests shall be made before the joints are covered so that any leaks may be readily detected. No leaks are allowed.
21.6.2 All underground pipelines in this system shall be tested at a pressure of 13 bar g (200 psig) for a period of not less than two hours (or for the length of time specified by the local authority), or at a pressure which exceeds by 3 bar g (50 psig) the prevailing maximum static pressures above
10 bar g (150 psig).
21.6.3 All tests shall be made in the presence of the local and/or state inspector and the Air Products representative.
21.6.4 Prior to conducting the leak test, every hydrant shall be opened, flushed, and closed to produce water hammer simulating actual fire-fighting conditions.
21.6.5 After the system testing has been completed and before it is permanently filled with water, the contractor shall thoroughly flush out the system through the hydrants. Water velocities of
1.5–2 meters/sec (5–6 ft/sec) must be maintained to move the larger obstructing materials from the underground piping. To obtain these velocities, the following flows shall be established:
DN150 (6 in NPS) Pipe – 31.5 liters/sec (500 gpm)
DM200 (8 in NPS) Pipe – 63 liters/sec (1000 gpm)
21.6.6 The contractor shall be responsible for completion and verification of Form QC-200A (found in specification 4WPI-EW44001) after testing and repairing of all piping and/or vessels, as required. These forms will be supplied by the Air Products representative. After the completion of all tests, they shall be signed by both parties and retained in their respective files.
22. DISINFECTION OF POTABLE WATER SYSTEM
22.1 Potable water systems shall be disinfected prior to use. The system shall be disinfected as required by state and local regulations using AWWA C651 as a guide.
22.1.1 The pipe system shall be flushed with clean, potable water until dirty water does not appear at the points of outlet.
22.1.2 Following the first flushing, a treatment with chlorine is recommended.
22.1.3 Following the treatment, the system shall be flushed with clean, potable water until chlorine does not remain in the water coming from the system, or until the chlorine residual is no greater than the local water source.
22.1.4 The procedure shall be repeated until a bacteriological examination in accordance with AWWA C651, Section 7 shows that contamination does not exist in the system.
22.1.5 Documentation indicating that a bacteriological examination has shown the system to be properly disinfected shall be given to the Air Products representative. The documentation shall include the bacterial test results certifying the water sampled from the new pipe to be free of coliform bacteria contamination, and to be equal or better than the bacteriologic water quality in the distribution system feeding the new pipe.
23. MISCELLANEOUS
23.1 See 4WCE-670200.
24. PATCHING, REPLACEMENT, AND MODIFICATION OF EXISTING WORK
24.1 See 4WCE-670200.
24.2 Repair of Damaged Sections
Segments of pipe having cuts or gouges in excess of 10% of the wall thickness of the pipe shall be cut out and removed. Follow manufacturer’s instructions for repair of damaged sections of pipe.
24.2.1 The undamaged portions of the HDPE pipe shall be rejoined using the butt fusion joining method.
24.2.2 The acceptable method for repairing faulty and leaking joints in solvent welded CPVC pipe is cutting out the faulty joint and replacing with a new section of pipe. Any proposed alternative method requires the approval of Air Products Engineering and the Air Products representative.
24.2.3 All repair work shall be approved by the Air Products representative.
24.3 Repair Tools and Materials
24.3.1 The tools and materials to do the job properly can be obtained from the pipe manufacturer.
24.4 Repair Area Preparation
24.4.1 Wipe all dirt, oil, and moisture from the joint area. A very mild solvent may be necessary to remove oil.
CAUTION
Make sure that all liquid has been removed from the portion of the piping system where the repair is to be made.
25. HIGHWAY AND RAILROAD CROSSINGs
25.1 Casings
25.1.1 Casings, where specified on contract drawings, shall be supplied to the size and wall thickness as specified in Figure 1.
25.1.2 Casings need not have a special protective coating unless specified in the project scope. Mill lacquer is acceptable when no protective coating has been specified.
25.1.3 Mill reject pipe is acceptable unless new and/or coated pipe is specified in the project scope.
25.1.4 The minimum required number of pipeline casing insulators shall be calculated by the following equation and rounded off to the next higher number:
N = + 3
Where: N = Number of casing insulators
L = Length of casing pipe (feet)
The insulators shall be installed in accordance with Figure 1.
25.2 Crossings
25.2.1 The pipeline construction at all highways, railroads, and principal access road crossings (including all details incidental to the installation of such crossings) shall comply with such specifications as may be required by the authority having jurisdiction and such specifications herein as may be applicable.
25.2.2 Comply with all city, county, state, or local railroad regulations relative to the maintenance of traffic, placing of danger signals, flares, and barricades. All costs of compliance shall be borne by the contractor.
25.2.3 All crossings of roads having a paved surface shall be accomplished by jacking or boring unless otherwise indicated on contract drawings. Slick boring is permitted for uncased crossings.
25.2.4 All casings shall have insulators (as required), end seals, and vent pipe(s) as required on contract drawings with a vent cap as shown in Figure 1.
Figure 1
Casing Details – Crossing Under Railroad or Railway
Notes:
- When noted on the contract drawings, casings shall have one low point and one high point vent pipe as shown.
- Insulators and seals shall be as shown in Appendix 1.
- Casing vent pipes shall be painted above grade in accordance with 4WEQ-6804.
- Unless otherwise noted on the pipeline drawings and/or as determined by governing authority.
- Mitered weld joints are not acceptable.
Table 2 – Casing Size and Wall Thickness
|
Pipeline Size mm (Inches) |
Casing
Size for Railroad mm (Inches) |
Casing
Size for Roadway mm (Inches) |
Minimum Wall Thickness for Railroad Casings
mm (Inches) |
Minimum Wall Thickness for Road Casings
mm (Inches) |
| 50 (2) | 150 (6) | 150 (6) | 5.0 (.188) | 6.4 (.250) |
| 75 (3) | 150 (6) | 150 (6) | 5.0 (.188) | 6.4 (.250) |
| 100 (4) | 200 (8) | 200 (8) | 5.0 (.188) | 6.4 (.250) |
| 200 (8) | 300 (12) | 300 (12) | 6.4 (.250) | 6.4 (.250) |
| 250 (10) | 400 (16) | 350 (14) | 7.2 (.281) | 6.4 (.250) |
| 300 (12) | 450 (18) | 400 (16) | 8.0 (.312) | 6.4 (.250) |
| 350 (14) | 500 (20) | 450 (18) | 8.8 (.344) | 8.0 (.312) |
| 400 (16) | 550 (22) | 500 (20) | 9.5 (.375) | 9.5 (.375) |
| 450 (18) | 600 (24) | 550 (22) | 10.4 (.407) | 10.4 (.407) |
| 500 (20) | 650 (26) | 600 (24) | 11.2 (.438) | 11.2 (.438) |
Appendix 1 – Miscellaneous Materials
| Item | Trade Name or Model | Manufacturer and Home Office |
| Casing End Seals
(Figure 1) |
Link-Seal Model Pl
(Preferred)
“Z” Seals
Model S |
Thundeline Corp.
Wayne, MI 48104
T.D. Williamson, Inc. Tulsa, OK 74101
PSI Industries, Inc. Burbank, CA 91504 |
| Casing Insulators
(Figure 1) |
Thinsulators M-2
Model PE |
T.D. Williamson, Inc.
Tulsa, OK 74101
PSI Industries, Inc. Burbank, CA 91504 |