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Plastic Process Piping

Rev1
IssuedOct 12, 2026
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1 Scope

NOTE This standard covers the pipe, fittings, flanges, joints, and installation of thermoplastic and fiberglass-reinforced plastic piping that carries process fluids and chemicals within a treatment plant or industrial process facility, from the first joint downstream of a tank, pump, or metering skid to the connection at the next item of equipment or structure. (1.1)
NOTE The boundary with the site standards is the plant fence. Yard piping that runs between plant structures inside the fence, whether a 24 in. HDPE filtered-water main in a trench or a 1 in. PVC hypochlorite line in a duct bank, is process piping under this standard. The plant's finished-water main once it leaves the fence, and site water service to buildings beyond it, are governed by Water Distribution PipingSite Water Distribution PipingResolves to the current adopted revision.sync/water-distribution-piping; sewers and force mains beyond the fence are governed by Sanitary Sewer SystemsSanitary Sewer Systems (Site)Resolves to the current adopted revision.sync/sanitary-sewer-systems, and lift stations beyond it by Packaged Pump StationsPackaged Pump and Lift StationsResolves to the current adopted revision.sync/packaged-pump-stations. (1.2)
NOTE Three sibling standards divide the process piping family by what the pipe is made of, and each owns its own pipe, fittings, joints, pressure test, and installation: Ductile Iron Process PipingDuctile Iron Process PipingResolves to the current adopted revision.sync/ductile-iron-process-piping, Steel And Stainless Process PipingSteel and Stainless Steel Process PipingResolves to the current adopted revision.sync/steel-and-stainless-process-piping, and this one for every thermoplastic and fiberglass product. Where a plastic line meets a metallic line, the transition fitting is governed here and the metallic side by its own sibling. (1.3)
NOTE Plastic piping is selected in a treatment plant because it is the material the chemical cannot attack, and it fails in service for reasons that have nothing to do with the chemical: a solvent joint pressurized before it cured, a threaded joint that cracked at the thread root, a run that was clamped at both ends and could not expand, a pipe left in the sun that turned chalky and brittle. This standard is prescriptive about those mechanisms and leaves the engineering selection among the materials to the datasheet and the piping schedule. (1.4)
1.5 Plastic process piping shall be designed, fabricated, installed, and tested in accordance with the design code selected in the datasheet, the material codes named in this standard, and the requirements of the Authority Having Jurisdiction.
1.6 The pipe size, pressure class or dimension ratio, material, fluid service, and design pressure and temperature of each line shall be as indicated on the piping schedule.
NOTE The following are outside this scope and are governed by the companion standards named. (1.7)
  • Ductile iron pipe and fittings, flanged and restrained-joint ductile iron, wall pipes with waterstop collars, and dismantling joints: Ductile Iron Process PipingDuctile Iron Process PipingResolves to the current adopted revision.sync/ductile-iron-process-piping.
  • Carbon steel and stainless steel process piping, including aeration air headers: Steel And Stainless Process PipingSteel and Stainless Steel Process PipingResolves to the current adopted revision.sync/steel-and-stainless-process-piping.
  • The process-discipline submittal procedures, trade coordination, and startup sequence inherited by every process standard: Common Work Results ProcessCommon Work Results for Process EquipmentResolves to the current adopted revision.sync/common-work-results-process.
  • Rubber-seated butterfly valves and eccentric plug valves: Butterfly ValvesButterfly ValvesResolves to the current adopted revision.sync/butterfly-valves and Eccentric Plug ValvesEccentric Plug ValvesResolves to the current adopted revision.sync/eccentric-plug-valves. Resilient-seated gate valves, process check valves, air release and vacuum valves, and valve and gate actuators: Resilient Seated Gate ValvesResilient-Seated Gate ValvesResolves to the current adopted revision.sync/resilient-seated-gate-valves, Process Check ValvesProcess Check ValvesResolves to the current adopted revision.sync/process-check-valves, Air Release And Vacuum ValvesAir Release and Vacuum ValvesResolves to the current adopted revision.sync/air-release-and-vacuum-valves, and Valve And Gate ActuatorsValve and Gate ActuatorsResolves to the current adopted revision.sync/valve-and-gate-actuators. Thermoplastic ball, diaphragm, and check valves for chemical service are not yet owned by a SynC standard.
  • Hanger and support hardware, structural attachments, and seismic bracing: Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current adopted revision.sync/hangers-and-supports.
  • Pipe markers, flow arrows, and valve tags: Mechanical IdentificationMechanical IdentificationResolves to the current adopted revision.sync/mechanical-identification.
  • Field painting of exposed piping: High Performance CoatingsHigh-Performance CoatingsResolves to the current adopted revision.sync/high-performance-coatings.
  • Electric heat tracing and pipe insulation: Electric Heat TracingElectric Heat TracingResolves to the current adopted revision.sync/electric-heat-tracing and Mechanical InsulationMechanical InsulationResolves to the current adopted revision.sync/mechanical-insulation.
  • Instrument process connections, root valves, and impulse tubing: Instrument Installation And TubingInstrument Installation and Impulse TubingResolves to the current adopted revision.sync/instrument-installation-and-tubing; analyzer sample lines: Analytical InstrumentationAnalytical InstrumentationResolves to the current adopted revision.sync/analytical-instrumentation.
  • Building domestic water, sanitary waste and vent, and hydronic piping in plastic: Domestic Water PipingDomestic Water PipingResolves to the current adopted revision.sync/domestic-water-piping, Sanitary Waste And Vent PipingSanitary Waste and Vent PipingResolves to the current adopted revision.sync/sanitary-waste-and-vent-piping, and Hydronic PipingHydronic PipingResolves to the current adopted revision.sync/hydronic-piping.
  • Disinfection of building domestic water systems: Disinfection Of Water SystemsDisinfection of Domestic Water SystemsResolves to the current adopted revision.sync/disinfection-of-water-systems.
  • Trench excavation, dewatering, shoring, and backfill above the pipe zone: EarthworkEarthworkResolves to the current adopted revision.sync/earthwork.
  • Chemical feed systems with their metering pumps, skids, and calibration columns; bulk chemical storage tanks; and building laboratory and chemical waste and vent piping, none of which is yet owned by a SynC standard; the water-retaining concrete structures the piping penetrates are under Water Retaining Concrete StructuresWater-Retaining Concrete StructuresResolves to the current adopted revision.sync/water-retaining-concrete-structures.

2 Referenced Standards

2.1 Materials, fabrication, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2 Where the Contract Documents, the adopted code, or a referenced standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
Standard Title
ASME B31.3 Process Piping
ASME B31.9 Building Services Piping
ASME NM.1 Thermoplastic Piping Systems
ASME NM.2 Glass-Fiber-Reinforced Thermosetting-Resin Piping Systems
ASME A13.1 Scheme for the Identification of Piping Systems
ASME B16.5 Pipe Flanges and Flanged Fittings, NPS 1/2 through NPS 24
ASME B16.21 Nonmetallic Flat Gaskets for Pipe Flanges
ASTM D1784 Rigid Poly(Vinyl Chloride) (PVC) Compounds and Chlorinated Poly(Vinyl Chloride) (CPVC) Compounds
ASTM D1785 Poly(Vinyl Chloride) (PVC) Plastic Pipe, Schedules 40, 80, and 120
ASTM D2241 Poly(Vinyl Chloride) (PVC) Pressure-Rated Pipe (SDR Series)
ASTM D2464 Threaded Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80
ASTM D2466 Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 40
ASTM D2467 Poly(Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80
ASTM D2564 Solvent Cements for Poly(Vinyl Chloride) (PVC) Plastic Piping Systems
ASTM F656 Primers for Use in Solvent Cement Joints of Poly(Vinyl Chloride) (PVC) Plastic Pipe and Fittings
ASTM D2855 Two-Step (Primer and Solvent Cement) Method of Joining Poly(Vinyl Chloride) (PVC) or Chlorinated Poly(Vinyl Chloride) (CPVC) Pipe and Piping Components with Tapered Sockets
ASTM F437 Threaded Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Pipe Fittings, Schedule 80
ASTM F438 Socket-Type Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Pipe Fittings, Schedule 40
ASTM F439 Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Pipe Fittings, Schedule 80
ASTM F441 / F441M Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Pipe, Schedules 40 and 80
ASTM F493 Solvent Cements for Chlorinated Poly(Vinyl Chloride) (CPVC) Plastic Pipe and Fittings
ASTM F1498 Taper Pipe Threads 60° for Thermoplastic Pipe and Fittings
ASTM F1970 Special Engineered Fittings, Appurtenances or Valves for use in Poly(Vinyl Chloride) (PVC) or Chlorinated Poly(Vinyl Chloride) (CPVC) Systems
ASTM D3139 Joints for Plastic Pressure Pipes Using Flexible Elastomeric Seals
ASTM F477 Elastomeric Seals (Gaskets) for Joining Plastic Pipe
AWWA C900 Polyvinyl Chloride (PVC) Pressure Pipe and Fabricated Fittings, 4 In. Through 60 In.
AWWA C605 Underground Installation of Polyvinyl Chloride (PVC) and Molecularly Oriented Polyvinyl Chloride (PVCO) Pressure Pipe and Fittings
AWWA M23 PVC Pipe: Design and Installation
ASTM D3350 Polyethylene Plastics Pipe and Fittings Materials
ASTM F714 Polyethylene (PE) Plastic Pipe (DR-PR) Based on Outside Diameter
ASTM D3035 Polyethylene (PE) Plastic Pipe (DR-PR) Based on Controlled Outside Diameter
AWWA C906 Polyethylene (PE) Pressure Pipe and Fittings, 4 In. Through 65 In., for Waterworks
AWWA M55 PE Pipe: Design and Installation
ASTM D3261 Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE) Plastic Pipe and Tubing
ASTM F1055 Electrofusion Type Polyethylene Fittings for Outside Diameter Controlled Polyethylene and Crosslinked Polyethylene Pipe and Tubing
ASTM F2206 Fabricated Fittings of Butt-Fused Polyethylene (PE)
ASTM F2880 Lap-Joint Type Flange Adapters for Polyethylene Pressure Pipe in Nominal Pipe Sizes 3/4 to 65
ASTM F2620 Heat Fusion Joining of Polyethylene Pipe and Fittings
ASTM F1290 Electrofusion Joining Polyolefin Pipe and Fittings
ASTM F3190 Heat Fusion Equipment (HFE) Operator Qualification on Polyethylene (PE) and Polyamide (PA) Pipe and Fittings
ASTM F3124 Data Recording the Procedure used to Produce Heat Butt Fusion Joints in Plastic Piping Systems
ASTM F2164 Field Leak Testing of Polyethylene (PE) and Crosslinked Polyethylene (PEX) Pressure Piping Systems Using Hydrostatic Pressure
PPI TR-4 HDB/HDS/SDB/PDB/MRS Listed Materials
PPI TR-33 Generic Butt Fusion Joining Procedure for Field Joining of Polyethylene Pipe
ASTM F2389 Pressure-Rated Polypropylene (PP) Piping Systems
ASTM D3222 Unmodified Poly(Vinylidene Fluoride) (PVDF) Molding, Extrusion and Coating Materials
ASTM D2310 Classification for Machine-Made "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
ASTM D2996 Filament-Wound "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
ASTM D2997 Centrifugally Cast "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
ASTM D6041 Contact-Molded "Fiberglass" (Glass-Fiber-Reinforced Thermosetting Resin) Corrosion Resistant Pipe and Fittings
ASTM D5685 "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pressure Pipe Fittings
ASTM D4024 Machine Made "Fiberglass" (Glass-Fiber-Reinforced Thermosetting Resin) Flanges
ASTM D5421 Contact Molded "Fiberglass" (Glass-Fiber-Reinforced Thermosetting Resin) Flanges
ASTM D2992 Obtaining Hydrostatic or Pressure Design Basis for "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe and Fittings
ASTM D3839 Underground Installation of "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
ASTM D4161 "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe Joints Using Flexible Elastomeric Seals
ASTM C581 Determining Chemical Resistance of Thermosetting Resins Used in Glass-Fiber-Reinforced Structures Intended for Liquid Service
ASTM D2321 Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications
ASTM D2774 Underground Installation of Thermoplastic Pressure Piping
ASTM D2837 Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis for Thermoplastic Pipe Products
NSF/ANSI/CAN 61 Drinking Water System Components: Health Effects
NSF/ANSI/CAN 372 Drinking Water System Components: Lead Content
NSF/ANSI 14 Plastics Piping System Components and Related Materials
AWWA C651 Disinfecting Water Mains
AWWA C655 Field Dechlorination
MSS SP-58 Pipe Hangers and Supports: Materials, Design, Manufacture, Selection, Application, and Installation

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following for the Engineer of Record's review and return before any plastic pipe, fitting, joining material, or containment component is procured:
  • Pipe product data for each material and service, identifying the material standard, cell classification or resin, schedule or dimension ratio, pressure rating at 73°F and the derated rating at the design temperature, and the potable-contact certification where the line carries finished or potable water
  • Fitting, flange, and flange adapter product data for each material and joining method, identifying the governing standard, pressure class, and the pipe wall or dimension ratio each fitting is matched to
  • A chemical compatibility tabulation listing every chemical service on the piping schedule with its concentration and design temperature, and for each the pipe, fitting, gasket, sealant, cement, and lining materials with the manufacturer's published resistance rating and the chemical supplier's recommendation
  • Solvent cement, primer, and thread sealant product data with the cure-time schedule for the pipe sizes, ambient temperatures, and test pressures of the project
  • Heat fusion procedure, fusion machine data, and the qualification record of each fusion operator under ASTM F3190
  • FRP pipe and fitting fabrication drawings identifying the resin, catalyst system, corrosion barrier construction, structural wall laminate, and joint construction for each line
  • Double-containment system product data covering carrier, containment, support spacers, termination and closure fittings, and the leak detection sensors and panel, with the system manufacturer's installation and testing procedure
  • Expansion compensation calculations and the proposed locations of offsets, loops, expansion joints, anchors, and guides for each exposed run
  • Thrust restraint calculations and restrained lengths for each buried gasketed or mechanical joint fitting
  • A pressure test plan identifying test boundaries, staging, test pressure, hold duration, isolation method, gauge selection, and the sequence that tests each portion before it is concealed, buried, or enclosed in containment
  • Piping coordination drawings for galleries, chemical rooms, and yard piping corridors showing routing, sizes, joint types, supports, anchors, and connections to equipment and wall pipes
Action Submittals Requiredcheckbox
☑ Pipe product data by material and service
☑ Fitting, flange, and flange adapter product data
☑ Chemical compatibility tabulation
☑ Solvent cement, primer, and thread sealant data with cure schedule
☑ Heat fusion procedure, machine data, and operator qualifications
☐ FRP fabrication drawings
☐ Double-containment system product data
☑ Expansion compensation calculations and layout
☐ Thrust restraint calculations
☑ Pressure test plan
☑ Piping coordination drawings
3.1.2 Work on a line shall not proceed until the submittals covering that line have been returned by the Engineer of Record.
3.1.3 Each submittal shall be internally consistent across pipe, fittings, joints, flanges, and gaskets for the same line, and the Contractor shall bear the cost of resubmission caused by internal inconsistency in its own submittal.

3.2 Closeout Submittals

3.2.1 The Contractor shall submit the following at substantial completion, before the plastic process piping work is accepted:
  • Signed and dated pressure test reports for every test boundary, recording the test pressure, hold duration, make-up water or pressure loss, and the pass determination
  • Fusion joint records listing each heat fusion and electrofusion joint by location, the operator, the machine, and the recorded fusion parameters where data logging is required
  • A solvent cement joint log recording the date, ambient temperature, and cement lot for each day's joints and the time each section was first pressurized
  • FRP field joint records listing each adhesive-bonded or butt-and-wrap joint, the bonder, the resin lot, and the cure verification
  • Leak detection system commissioning report demonstrating alarm response from every sensor and the signal received at the plant control system
  • Bacteriological clearance results and chlorine residual records for every plant potable or finished-water line disinfected under this standard
  • As-built drawings recording the installed routing, sizes, joint types, anchor, guide, and expansion joint locations, tracer wire termination points, and the locations of concealed and buried joints and fittings
  • Tracer wire continuity test results for every buried run
Closeout Submittals Requiredcheckbox
☑ Signed pressure test reports for every test boundary
☑ Fusion joint records
☐ Solvent cement joint log
☐ FRP field joint records
☐ Leak detection commissioning report
☐ Bacteriological clearance and residual records
☑ As-built drawings
☑ Tracer wire continuity test results

4 Quality Assurance

4.1 Installer and Joiner Qualification

4.1.1 The contractor installing plastic process piping shall have completed at least three treatment plant or industrial process piping installations comparable to this project in material, scope, and complexity within the preceding five years, and shall submit those project references on request.
4.1.2 Where the parties disagree whether a submitted reference project is comparable in material, scope, and complexity, the Engineer of Record shall make the initial determination.
4.1.3 Personnel making heat fusion or electrofusion joints in polyethylene, polypropylene, or PVDF shall hold a current qualification under ASTM F3190 for the fusion process, the machine, and the pipe size range in use, issued within the preceding twelve months.
4.1.4 Personnel making solvent-cemented joints shall have completed the cement manufacturer's training in the two-step joining procedure of ASTM D2855 before making a production joint.
4.1.5 Personnel making adhesive-bonded or butt-and-wrap joints in FRP piping shall have been trained and certified by the FRP pipe manufacturer for the joint type and resin system in use.
4.1.6 Personnel installing double-containment piping shall have completed the containment system manufacturer's installation training for the system in use.
4.1.7 Joints made by personnel who were not qualified at the time the joint was made shall be cut out and remade, and the Contractor shall bear the cost of the removal, the replacement material, the remake, the retest, and the repair of any other trade's work disturbed by that removal.
NOTE A qualification requirement for every joining process exists because none of these joints can be inspected after it is made. A fused joint with the wrong heat soak, a solvent joint made without primer, and an FRP bond laid up on an unsanded surface all look complete, hold a short test, and fail in service. The only control available is the person and the procedure. (4.1.8)
NOTE Material Certification and Listing (4.2)
4.2.1 Every thermoplastic pipe and fitting shall bear the manufacturer's name, the material standard, the nominal size, the schedule or dimension ratio, the material designation code, and the mark of the certifying body under NSF/ANSI 14.
4.2.2 Pipe, fittings, gaskets, cements, and linings in contact with plant potable or finished water shall be certified to NSF/ANSI/CAN 61 and NSF/ANSI/CAN 372.
4.2.3 Polyethylene pipe and fitting compound shall carry a current listing in PPI TR-4 for the hydrostatic design basis the pressure rating is derived from.
4.2.4 FRP pipe shall be manufactured by a fabricator who has produced pipe of the same construction and resin system under ASME NM.2 or ASTM D2996, D2997, or D6041 for at least five years, and the fabricator shall certify each shipment to the submitted fabrication drawings.
4.2.5 The Contractor shall keep a copy of the selected design code and of ASME NM.1 and NM.2 at the site throughout installation.

5 Design Basis and Service Conditions

5.1 Governing Code and Fluid Service

5.1.1 The design code governing plastic process piping shall be as indicated in the datasheet.
Design Coderadio
● ASME B31.3 Process Piping
○ ASME B31.9 Building Services Piping, within its pressure and temperature limits
NOTE ASME B31.3 is the code written for piping that carries chemicals, carries fluid service categories that distinguish a harmless utility line from a toxic one, and references the nonmetallic material codes ASME NM.1 and NM.2 directly, which is why it is the baseline for a plant. ASME B31.9 covers building services within its limits and is selected where the plastic piping is confined to utility water inside a building on a project that has adopted B31.9 for its mechanical work and has no chemical service to classify. (5.1.2)
5.1.3 Thermoplastic piping shall comply with ASME NM.1 and FRP piping with ASME NM.2 as the material and fabrication codes under the selected design code.
5.1.4 The fluid service category of each chemical line under ASME B31.3 shall be as indicated on the process and instrumentation diagrams.
5.1.5 A line in Category M fluid service shall be double contained regardless of any other designation.

5.2 Pressure and Temperature Rating

5.2.1 Every pipe, fitting, flange, gasket, joint, and transition component shall be rated by its manufacturer for not less than the design pressure of the line at the design temperature of the line.
5.2.2 The pressure rating of thermoplastic pipe and fittings at the design temperature shall be the rating at 73°F multiplied by the manufacturer's published temperature derating factor, and the derated rating shall govern.
NOTE A rating derated for temperature is the central fact of plastic piping design. PVC loses about 40% of its pressure rating at 100°F and about 78% at 140°F, where its service ends; polyethylene loses about 22% at 100°F and half at 140°F; CPVC and PVDF hold their ratings to higher temperatures, which is why they appear on the schedule for hot or heat-traced lines. A line rated from the catalog at 73°F and installed next to a heat-traced line, under a roof, or in the sun is a line whose true rating nobody checked. (5.2.3)
5.2.4 Exposed outdoor piping shall be rated at the pipe wall temperature that results from solar exposure at Site Ambient Temperature MaximumSite Ambient Temperature MaximumParameterEach project supplies its own value.site-ambient-temperature-maximum, or at the fluid design temperature, whichever is greater.
5.2.5 The pressure rating of a solvent-cemented, fused, or bonded joint shall be not less than the rating of the pipe it joins, and the rating of a threaded joint shall be the pipe manufacturer's published rating for threaded pipe of that schedule.
5.2.6 Thermoplastic and FRP pipe and fittings shall not be used in compressed air or other compressed gas service unless the pipe manufacturer publishes a rating for compressed gas service and the line is designated for that service on the piping schedule.
NOTE A thermoplastic pipe that fails under compressed gas does not split and leak as it does under water; it shatters, because the gas stores elastic energy that water does not and the material has little ductility at the strain rate of a burst. The pipe standards, the manufacturers, and the federal occupational safety authority have each warned against PVC in compressed air service since the 1980s, which is why the prohibition is unconditional for a material not rated for gas and why a line that is rated for it must be identified on the schedule. (5.2.7)

5.3 Chemical Compatibility

5.3.1 For each chemical service, the pipe, fittings, gaskets, sealants, cements, linings, and transition components shall be rated by their manufacturers as resistant to the chemical at the concentration and the design temperature indicated on the piping schedule.
5.3.2 Chemical compatibility shall be demonstrated against both the piping manufacturer's published chemical resistance data and the chemical supplier's materials-of-construction recommendation, and where the two differ, the more restrictive rating shall govern.
5.3.3 Where the parties disagree whether a material is compatible with a chemical service, the Engineer of Record shall make the initial determination.
NOTE Compatibility is a property of the chemical, its concentration, and its temperature together, which is why this standard carries no single material rating for any chemical. Sodium hypochlorite at 12.5% attacks materials that resist it at 0.5%; concentrated sulfuric acid is carried in materials that dilute sulfuric acid destroys; a ferric chloride line at 70°F and the same line heat-traced to 100°F have different acceptable gaskets. The piping schedule names the chemical and its concentration for each line, and the compatibility tabulation in the action submittal is where the pairing is proved. (5.3.4)
NOTE Sodium hypochlorite decomposes continuously and releases oxygen as it does, so a hypochlorite line closed at both ends builds pressure with no flow, and the stress on every joint rises while the chemical is attacking it. Threaded plastic joints in hypochlorite service are the most frequent leak point in a chemical feed room, because the thread root concentrates stress in a material the chemical is already weakening and the sealant between the threads is the first material to go. (5.3.5)
5.3.6 Thermoplastic pipe in a chemical service identified on the piping schedule as a stress-cracking or environmental-stress-cracking agent for that material shall not be threaded, bent, or clamped in a manner that introduces sustained tensile stress at the wetted surface.

5.4 Site Service Conditions

5.4.1 Exposed outdoor piping shall be selected and supported for continuous service across the range from Site Ambient Temperature MinimumSite Ambient Temperature MinimumParameterEach project supplies its own value.site-ambient-temperature-minimum to Site Ambient Temperature MaximumSite Ambient Temperature MaximumParameterEach project supplies its own value.site-ambient-temperature-maximum.
5.4.2 Seismic bracing of plastic process piping shall be provided under Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current adopted revision.sync/hangers-and-supports wherever the adopted building code requires it for Seismic Design CategorySeismic Design CategoryParameterEach project supplies its own value.seismic-design-category.
NOTE PVC becomes markedly less resistant to impact below about 32°F and polyethylene stays ductile well below that, which is one of the reasons a buried or outdoor line that sees a northern winter is more often specified in polyethylene while an indoor chemical line is more often specified in PVC. The ambient range also sets whether solvent cement can be used outdoors in winter at all, because below the cement manufacturer's minimum temperature the solvent does not soften the pipe wall enough to fuse. (5.4.3)

6 Polyvinyl Chloride and Chlorinated Polyvinyl Chloride Piping

6.1 PVC Pipe and Fittings

6.1.1 PVC pipe and fittings shall be manufactured from compound conforming to ASTM D1784, cell classification 12454.
6.1.2 Exposed PVC pipe shall conform to ASTM D1785, with socket fittings conforming to ASTM D2466 for Schedule 40 and ASTM D2467 for Schedule 80, and threaded fittings conforming to ASTM D2464.
6.1.3 The minimum wall schedule for exposed PVC piping shall be as indicated in the datasheet, and a heavier wall shall be used where the piping schedule requires it for a particular line.
Minimum Wall Schedule for Exposed PVC Pipingselect
Schedule 40
Schedule 80
Schedule 120
6.1.5 Special engineered fittings, saddles, and appurtenances in PVC and CPVC shall conform to ASTM F1970.
6.1.6 All pipe and fittings shall be new, shall bear the markings required by their standards, and shall be free of cracks, gouges, chalking, and discoloration.

6.2 CPVC Pipe and Fittings

6.2.1 CPVC pipe and fittings shall be manufactured from compound conforming to ASTM D1784, cell classification 23447.
6.2.2 CPVC pipe shall conform to ASTM F441 / F441M, with socket fittings conforming to ASTM F438 for Schedule 40 and ASTM F439 for Schedule 80, and threaded fittings conforming to ASTM F437.
6.2.3 The minimum wall schedule for CPVC piping shall be as indicated in the datasheet.
Minimum Wall Schedule for CPVC Pipingradio
○ Schedule 40
● Schedule 80
NOTE CPVC is selected over PVC where the design temperature exceeds the point at which PVC has lost most of its rating, roughly 120°F to 140°F, and it carries a useful rating to about 200°F. It costs more than PVC, requires its own cement, and in some oxidizing chemical services is less resistant than PVC at the same concentration, which is why the material is a line-by-line selection on the piping schedule rather than a plant-wide one. (6.2.4)
6.2.5 PVC pipe, PVC fittings, and PVC solvent cement shall not be used in a CPVC line, and CPVC cement shall not be used to join PVC.

6.3 Solvent-Cemented Joints

6.3.1 Solvent-cemented joints in PVC shall be made with primer conforming to ASTM F656 and cement conforming to ASTM D2564, and joints in CPVC with primer conforming to ASTM F656 and cement conforming to ASTM F493, by the procedure of ASTM D2855.
6.3.2 The solvent cement system shall be as indicated in the datasheet.
Solvent Cement Systemradio
● Two-step system, a primer followed by a separate solvent cement
○ One-step solvent cement without a separate primer
NOTE The primer in a two-step system softens the pipe and socket surfaces before the cement is applied, so the cement fuses two softened surfaces rather than coating two hard ones, and the two-step method is the one ASTM D2855 describes and the one plant specifications almost always require for pressure and chemical service. A one-step cement carries its own softening solvents and is accepted by some jurisdictions and some manufacturers for the smaller sizes and lower pressures; it is selected where the pipe manufacturer lists it for the size, schedule, and pressure of the line. (6.3.3)
6.3.4 Solvent cement and primer shall be the products listed by the pipe manufacturer for the pipe material, schedule, and size, and shall be within their marked shelf life and stored within the temperature range their manufacturer publishes.
6.3.5 Solvent cement that has thickened, gelled, or separated shall be discarded and shall not be thinned for use.
6.3.6 Pipe shall be cut square, deburred inside and out, and chamfered on the outside edge before the joint is made.
6.3.7 Each joint shall be assembled with the pipe inserted to the full socket depth with a quarter turn, held until the cement sets, and left with a continuous bead of cement at the mouth of the socket.
NOTE A joint assembled without the quarter turn, or without the pipe bottomed in the socket, has cement spread unevenly across the interference fit and an unbonded band at the socket bottom that becomes the leak path after a year of thermal cycling. The bead at the socket mouth is the only visible evidence that enough cement was applied, which is why it is required rather than wiped off. (6.3.8)
6.3.9 A solvent-cemented joint shall not be moved, pressurized, or tested until the cure time published by the cement manufacturer for the pipe size, the ambient temperature, and the intended test pressure has elapsed.
6.3.10 Solvent cementing shall not be performed at an ambient temperature outside the range the cement manufacturer publishes, nor in rain, nor where the joint surfaces are wet.
6.3.11 Where the ambient temperature is below 40°F, the Contractor shall follow the cement manufacturer's published cold-weather procedure and shall extend the cure time to the published cold-weather value.
6.3.12 The area in which solvent cementing is performed shall be ventilated as the cement safety data sheet requires, and open flame and hot work shall be excluded from it while cement is in use.

6.4 Threaded Joints in PVC and CPVC

6.4.1 Threaded joints in PVC and CPVC shall be permitted as indicated in the datasheet.
Threaded Joints in PVC and CPVCradio
● Not permitted except at a threaded connection on an item of equipment or an instrument
○ Permitted in Schedule 80 pipe up to the maximum size indicated
NOTE Threading removes roughly half the wall of a Schedule 80 pipe and leaves a notch at every thread root, so a threaded plastic joint carries about half the pressure rating of the pipe and concentrates every bending and thermal stress at the point the material can least afford it. Most plant specifications confine threads to the few places a threaded equipment or instrument port leaves no alternative; projects that permit them more widely are those with small, low-pressure utility lines where the repeated disassembly a threaded joint allows is worth the margin it costs. (6.4.2)
6.4.3 Where the datasheet permits threaded joints, they shall be limited to Schedule 80 pipe and to pipe sizes not exceeding the size indicated in the datasheet.
Pipe Size for Threaded Plastic Jointsrange
in. NPS
0.50.7511.251.5234
Default: Not more than 2 in. NPS
6.4.4 Threads in thermoplastic pipe and fittings shall conform to ASTM F1498, and a plastic male thread shall be engaged into a metallic female thread rather than a metallic male into a plastic female.
NOTE A metal male thread driven into a plastic female fitting wedges the fitting outward with every turn and with every thermal cycle, and the fitting splits along the thread. Plastic male into metal female puts the plastic in compression, which it tolerates. (6.4.5)
6.4.6 Thread sealant shall be a polytetrafluoroethylene tape or a paste sealant listed by its manufacturer for the plastic material and the chemical service, and petroleum-based or solvent-based thread compounds shall not be used.
6.4.7 Threaded plastic joints shall be made up by hand plus no more than one additional turn with a strap wrench, and pipe wrenches shall not be used on plastic pipe or fittings.

6.5 Buried PVC Pressure Pipe

6.5.1 Buried PVC pressure pipe shall be the product and joint indicated in the datasheet.
Buried PVC Pressure Pipeselect
AWWA C900 with gasketed push-on joints
ASTM D2241 SDR pipe with gasketed joints
ASTM D2241 SDR pipe with solvent-cemented joints
ASTM D1785 Schedule 80 pipe with solvent-cemented joints
Not applicable (no buried PVC pressure pipe on the project)
NOTE AWWA C900 pipe is the waterworks product, dimensioned to the ductile iron outside diameter so it takes ductile iron fittings and valves directly, joined with a gasketed bell that flexes with the trench and needs no cure time, and it is the usual selection for the 4 in. and larger yard mains between plant structures. ASTM D2241 SDR pipe is dimensioned to iron pipe size and fits the solvent-weld fitting range, so it is selected where a buried line continues a Schedule 80 exposed system of the same size; its gasketed form gives the same trench flexibility as C900 in the sizes C900 does not cover. A buried solvent-cemented line is rigid, needs no thrust restraint at fittings, and has to cure in the trench before it can be tested or backfilled, which suits the small chemical lines and is a liability on a long main. (6.5.2)
6.5.3 Gasketed joints in PVC shall conform to ASTM D3139, with elastomeric gaskets conforming to ASTM F477 and of a compound rated for the fluid in the line.
6.5.4 Gasketed joints shall be assembled with the gasket lubricant furnished by the pipe manufacturer, to the insertion mark, and shall not be inserted past the mark.
NOTE A spigot driven past the insertion mark bottoms in the bell and leaves no room for the thermal and settlement movement the gasketed joint was selected to absorb, so the next cold night or the first trench settlement loads the bell in a way it was not designed for. (6.5.5)
6.5.6 Fittings for AWWA C900 pipe shall be ductile iron mechanical joint or push-on fittings furnished under Ductile Iron Process PipingDuctile Iron Process PipingResolves to the current adopted revision.sync/ductile-iron-process-piping, or fabricated PVC fittings conforming to AWWA C900.

7 Polyethylene Piping

7.1 HDPE Pipe and Fittings

7.1.1 Polyethylene pipe and fittings shall be manufactured from compound conforming to ASTM D3350 with the material designation indicated in the datasheet, and the compound shall include carbon black for ultraviolet protection.
Polyethylene Material Designationselect
PE 4710
PE 3608
PE 2708
NOTE PE 4710 is the high-density, high-performance compound that current waterworks and process pipe is extruded from; it carries a higher hydrostatic design stress than the older designations, so the same dimension ratio yields a higher pressure rating, and it is what AWWA C906 pipe is normally supplied in. PE 3608 is the previous generation of high-density compound, still produced and still listed, and it is selected where an existing plant system in that material is being extended with matching pipe. PE 2708 is a medium-density compound with greater flexibility and slow-crack-growth resistance, used mainly in small-diameter and gas-service pipe, and it is selected for a process line only where that flexibility is wanted and the lower pressure rating is acceptable. (7.1.2)
7.1.3 Polyethylene pipe 4 in. and larger shall conform to AWWA C906 or ASTM F714, and pipe smaller than 4 in. shall conform to ASTM D3035.
7.1.4 The outside diameter basis of polyethylene pipe shall be as indicated in the datasheet.
Polyethylene Outside Diameter Basisradio
○ Iron pipe size (IPS)
○ Ductile iron pipe size (DIPS)
NOTE Iron pipe size polyethylene matches the fitting, flange adapter, and valve range of steel and PVC process piping and is the usual choice for an exposed or process-building system. Ductile iron pipe size matches the outside diameter of ductile iron pipe, so a buried polyethylene yard main in that size connects to ductile iron fittings, valves, and mechanical joint adapters with no transition, and it is the usual choice for a main that ties into a ductile iron system. The two are not interchangeable in fittings or in fusion, and a project that mixes them has to carry both fitting inventories. (7.1.5)
7.1.6 The maximum dimension ratio of polyethylene pipe on the project shall be as indicated in the datasheet, and a thicker wall shall be used where the piping schedule requires it for a particular line.
Polyethylene Dimension Ratiorange
77.391113.515.517212632.5
NOTE A lower dimension ratio is a thicker wall for the same outside diameter. DR 11 in PE 4710 is rated 200 psi at 73°F and is the wall most plant yard piping and process lines are written around; DR 17 and higher carry the lower ratings of gravity and low-pressure service at less material; DR 9 and below buy pressure rating or surge margin at a smaller bore and a slower fusion cycle. Each line's own DR follows its design pressure on the piping schedule, and the project maximum here is the floor on wall thickness the engineer sets for handling and surge regardless of pressure. (7.1.7)
7.1.8 Butt fusion fittings shall conform to ASTM D3261, electrofusion fittings to ASTM F1055, and fabricated fittings to ASTM F2206, and every fitting shall carry a pressure rating not less than the pipe it joins.
7.1.9 A fabricated fitting of lower pressure rating than the pipe shall not be used unless the piping schedule indicates a design pressure the fitting rating satisfies.
7.1.10 Polyethylene pipe shall not be bent to a radius less than the pipe manufacturer's published minimum for its dimension ratio, and not less than 100 times the outside diameter where a fitting, flange, or fusion joint lies within the bend.

7.2 Heat Fusion Joints

7.2.1 The field joint for polyethylene pipe shall be as indicated in the datasheet.
Polyethylene Field Jointselect
Butt fusion
Electrofusion
Socket fusion
Restrained mechanical coupling with internal stiffener
NOTE Butt fusion makes a joint as strong as the pipe, fully restrained, and leak-free for the life of the material, which is why it is the baseline for polyethylene; it needs a fusion machine at every joint and clear space to swing the pipe into the clamps. Electrofusion needs no machine beyond a control box and is the joint for tie-ins, repairs, and places the pipe cannot be moved, at a higher cost per fitting and a stricter surface-preparation discipline. Socket fusion serves the small sizes a butt machine does not handle well. A restrained mechanical coupling is made with a wrench, is selected for a connection that has to be taken apart or made where fusion equipment cannot reach, and depends on an internal stiffener to keep the polyethylene from creeping away from the coupling's grip. (7.2.2)
7.2.3 Butt fusion joints shall be made in accordance with ASTM F2620 and PPI TR-33 using the heater temperature, interfacial pressure, heat soak, and cooling time published for the pipe material, dimension ratio, and size.
7.2.4 Pipe ends shall be faced square and clean immediately before fusion, aligned to within ten percent of the wall thickness, and the heater plate shall be clean and within its temperature range at every joint.
7.2.5 The fused joint shall not be removed from the machine clamps or stressed until the published cooling time has elapsed.
7.2.6 Each butt fusion joint shall be visually inspected for a uniform, symmetrical double bead rolled back to the pipe surface with no voids, misalignment, or unfused areas, and a joint that fails inspection shall be cut out and remade.
7.2.7 The recording of butt fusion parameters shall be as indicated in the datasheet.
Butt Fusion Data Recordingradio
○ Required for every butt fusion joint, by a data logger in accordance with ASTM F3124
○ Not required beyond the fusion joint record
7.2.9 The external fusion bead shall be treated as indicated in the datasheet.
External Butt Fusion Beadradio
○ Left in place
○ Removed and retained for inspection of the bead cross-section
NOTE The bead itself is not a weakness and most joints leave it in place. Removing the external bead with a bead-removal tool lets the inspector bend the bead strip back on itself and look for the voids and cold-fusion lines that a joint fused outside its parameters produces, and a run of beads retained by joint number is a record that supplements or substitutes for data logging. Bead removal is also required where the pipe is pulled through a casing or a bore that the bead would hang on. (7.2.10)
7.2.11 Fusion shall not be performed in rain, in standing water, or in wind that cools the heater plate or the joint faces, unless the joint is sheltered.

7.3 Electrofusion and Mechanical Joints

7.3.1 Electrofusion joints shall be made in accordance with ASTM F1290 using the fitting manufacturer's control box, with the pipe surface scraped to remove the oxidized layer over the full fusion zone, cleaned, and clamped in alignment through the fusion and cooling cycles.
NOTE An electrofusion fitting fuses to the pipe surface it touches, and the oxidized skin a polyethylene pipe grows in storage does not fuse. A joint made on an unscraped pipe looks identical to a good one and parts under pressure along the oxide line. The scraped band is the only visible evidence, which is why the scraping tool, not a sanding cloth, is specified. (7.3.2)
7.3.3 Electrofusion joints shall be made with a mechanical scraping tool that removes a measured depth of pipe surface, and abrasive cloth or paper shall not be used in its place.
7.3.4 Mechanical couplings on polyethylene pipe shall be restrained against pullout, rated for the design pressure, and fitted with an internal stiffener where the coupling grips the outside of the pipe.
NOTE Polyethylene creeps under a sustained radial load, so a compression coupling that bites the outside of the pipe loses its grip over months unless a stiffener inside the pipe holds the wall against the coupling. An unrestrained coupling on a fused system also removes the restraint the fused joints provided, and the line walks out of the coupling under pressure thrust. (7.3.5)

7.4 Polyethylene Flange Connections

7.4.1 Flanged connections in polyethylene piping shall be made with butt-fused flange adapters conforming to ASTM F2880 and loose backing rings drilled to the ASME B16.5 Class 150 bolt pattern.
7.4.2 The backing ring material shall be as indicated in the datasheet.
Polyethylene Flange Backing Ring Materialselect
Ductile iron, fusion-bonded epoxy coated
Carbon steel, coated
Stainless steel, Type 304
Stainless steel, Type 316
Not applicable (no flanged polyethylene connections)
7.4.4 Flange bolting on polyethylene flange adapters shall be tightened in a crossing pattern in stages to the torque published by the adapter manufacturer, and shall be retightened after the published relaxation interval before the line is placed in service.
NOTE Polyethylene relaxes under the bolt load for the first hours after assembly, and a flange torqued once to the published value is below it by the next morning. The retightening is not optional maintenance; it is the second half of making the joint. (7.4.5)
7.4.6 A polyethylene flange adapter mated to a metallic raised-face flange shall be assembled with a full-face gasket and shall not be used against a raised face without one.

8 Polyvinylidene Fluoride and Polypropylene Piping

8.1 PVDF pipe and fittings shall be manufactured from unpigmented resin conforming to ASTM D3222, in the schedule or standard dimension ratio indicated on the piping schedule, with a pressure rating at 73°F of not less than 150 psi.
8.2 Polypropylene pipe and fittings shall conform to ASTM F2389, in the standard dimension ratio indicated on the piping schedule.
NOTE PVDF is the thermoplastic selected where the chemical defeats PVC and CPVC: concentrated and heated sodium hypochlorite, chlorine solutions, hydrofluoric and nitric acids, and the halogenated and oxidizing services, and it holds a pressure rating to about 250°F. It is attacked by strong caustics and by some ketones and amines, so a sodium hydroxide line is not a PVDF line. Polypropylene resists caustics and many organic solvents, costs far less than PVDF, and is attacked by strong oxidizers, so the two materials tend to divide the chemical room between them rather than compete for the same line. (8.3)
8.4 PVDF and polypropylene piping shall be joined by the method indicated in the datasheet.
PVDF and Polypropylene Joining Methodselect
Socket fusion
Butt fusion
Infrared butt fusion without contact between the heater and the pipe
Bead-and-crevice-free fusion
Not applicable (no PVDF or polypropylene piping on the project)
NOTE Socket fusion is the joint for the small sizes and is made with hand tooling; butt fusion serves the larger sizes with the same discipline as polyethylene. Infrared fusion heats the ends without touching them, so no material is transferred from a heater plate and the bead is smaller and more repeatable, which is why it is selected for high-purity and for the most aggressive chemical services. Bead-and-crevice-free fusion leaves a smooth bore with no bead and no crevice for solids or chemical to lodge in, at the highest tooling cost, and is selected where the fluid is a slurry that packs behind a bead or a chemical that concentrates in a crevice. (8.5)
8.6 Fusion joints in PVDF and polypropylene shall be made with the tooling, heater temperature, and dwell and cooling times published by the pipe manufacturer for the material, size, and wall, by operators qualified under this standard.
8.7 Threaded joints shall not be used in PVDF or polypropylene pressure piping except at a threaded connection on an item of equipment or an instrument, where a transition fitting with a molded thread shall be used.
8.8 PVDF exposed to sunlight shall be protected under the Ultraviolet and Weather Protection article of this standard unless the pipe manufacturer publishes an ultraviolet rating for the unprotected product.

9 Fiberglass-Reinforced Plastic Piping

9.1 FRP Pipe Construction

9.1.1 FRP pipe shall be manufactured by the method indicated in the datasheet, and shall conform to ASTM D2996 for filament-wound pipe, ASTM D2997 for centrifugally cast pipe, or ASTM D6041 for contact-molded pipe.
FRP Pipe Manufacturing Methodselect
Filament wound
Centrifugally cast
Contact molded
Not applicable (no FRP piping on the project)
NOTE Filament-wound pipe carries continuous glass at a controlled winding angle, so it has the highest hoop and axial strength for its wall and is the usual construction for pressure piping in the standard sizes. Centrifugally cast pipe is formed inside a rotating mold, which gives it a smooth, resin-rich outside and a wall that is reliably round and uniform, and it is selected for buried and gravity service and where the exterior is the corrosion face. Contact-molded pipe is laid up by hand against a mandrel to whatever laminate the service needs, so it is the construction for large diameters, odd fittings, and the heavy corrosion barriers of the most aggressive services, at the highest cost and the widest dimensional tolerance. (9.1.2)
9.1.3 FRP pipe shall be classified under ASTM D2310 and shall carry a pressure rating derived from a hydrostatic design basis established under ASTM D2992 for the resin and construction supplied.
9.1.4 FRP fittings shall conform to ASTM D5685 and shall be manufactured with the same resin system and corrosion barrier as the pipe they join.
9.1.5 FRP flanges shall conform to ASTM D4024 for machine-made flanges or ASTM D5421 for contact-molded flanges, drilled to the ASME B16.5 Class 150 bolt pattern, and flat faced.

9.2 FRP Resin and Corrosion Barrier

9.2.1 The resin system of FRP pipe and fittings shall be as indicated in the datasheet, and the resin selected shall be rated by its manufacturer for the chemical service of the line under ASTM C581.
FRP Resin Systemselect
Isophthalic polyester
Bisphenol A fumarate polyester
Vinyl ester
Novolac vinyl ester
Aromatic amine-cured epoxy
Furan
Not applicable (no FRP piping on the project)
NOTE Isophthalic polyester is the least costly resin and serves water, mild acids, and salt solutions to moderate temperatures. Bisphenol A fumarate polyester extends the chemical range into stronger acids and some caustics. Vinyl ester is the general chemical-service resin, resisting most acids, hypochlorite, and caustics with better toughness than the polyesters, and it is the resin most treatment plant FRP is written around; novolac vinyl ester buys higher temperature and solvent resistance over it. Epoxy carries the highest strength and the best resistance to caustics and solvents, at the highest cost and with a cure that is sensitive to field conditions. Furan is the resin for solvents and mixed acid and solvent services that defeat the others, and it is black, brittle, and seldom stocked. (9.2.2)
9.2.3 The corrosion barrier on the inside surface of FRP pipe and fittings shall be a resin-rich layer of not less than the thickness indicated in the datasheet, reinforced with the surfacing veil indicated in the datasheet and backed by chopped-strand mat.
FRP Corrosion Barrier Thicknessrange
mils
102050100120150200
FRP Inner Surface Veilradio
○ C-glass veil
○ Synthetic polyester veil
○ Carbon veil
○ Not applicable (no FRP piping on the project)
NOTE The corrosion barrier is the part of an FRP pipe that meets the chemical, and the structural wall behind it is designed on the assumption that the barrier keeps the chemical out. A 100 mil barrier with a 10 to 20 mil veil layer is the construction most chemical service pipe is built to; thinner barriers serve water and mild service where the resin itself is not under attack, and thicker barriers are specified for hot or strongly oxidizing service where the barrier is consumed over the design life. The veil sets what the chemical first touches: C-glass resists most acids and is attacked by hydrofluoric acid and strong caustics; a synthetic veil has no glass to attack and is selected for hypochlorite, caustic, and fluoride services; a carbon veil is conductive and is selected where a flammable fluid requires the pipe to dissipate static charge. (9.2.4)
9.2.5 The exterior surface of FRP pipe installed outdoors shall be a resin-rich layer with an ultraviolet absorber or a pigmented topcoat applied by the pipe manufacturer.

9.3 FRP Joints

9.3.1 Field joints in FRP piping shall be of the type indicated in the datasheet.
FRP Field Jointselect
Adhesive-bonded bell and spigot
Butt-and-wrap
Flanged
Gasketed bell and spigot
Not applicable (no FRP piping on the project)
NOTE An adhesive-bonded bell and spigot is the joint of the standard sizes: the spigot is machined to a taper, the bell is matched, and a thin adhesive bond line carries the load with no laminating in the field. A butt-and-wrap joint is laid up in the field with the same laminate as the pipe wall and is the joint of large diameters, contact-molded pipe, and any place the pipe cannot be pushed into a bell; it needs a trained laminator and a cure, and it is the strongest of the four. Flanged joints are made wherever the line has to come apart, at every valve and every item of equipment, and nowhere else, because each flange is a thick, costly, stress-concentrating component. A gasketed bell and spigot under ASTM D4161 is a buried joint, unrestrained, that absorbs ground movement and needs thrust restraint at every fitting. (9.3.2)
9.3.3 Adhesive-bonded joints shall be made with the adhesive supplied by the pipe manufacturer for the resin system, on surfaces sanded to fresh laminate within the working time of the adhesive, and shall be cured at the temperature and for the duration the manufacturer publishes before the joint is loaded.
9.3.4 Butt-and-wrap joints shall be laid up with the resin, veil, mat, and woven roving sequence of the pipe manufacturer's joint drawing, over a surface sanded to fresh laminate for the full wrap width, and shall be cured and checked for hardness before the joint is loaded.
NOTE An adhesive or a laminate applied over the glossy, resin-rich surface of an FRP pipe does not bond to it; it bonds to the mold release and the surface resin, and peels with them. Sanding to expose fresh laminate is the entire difference between a joint and a sleeve, and a sanded surface left overnight has to be sanded again. (9.3.5)
9.3.6 Field cure of FRP joints shall be accelerated by heat where the ambient temperature is below the adhesive or resin manufacturer's minimum, using the heating blanket or method the manufacturer publishes, and a joint shall not be made where the surfaces are wet or below the dew point.

10 Flanged Connections and Transitions to Metallic Piping

10.1 Plastic Flanges and Gaskets

10.1.1 Flanges in PVC, CPVC, PVDF, and polypropylene piping shall be of the construction indicated in the datasheet, drilled to the ASME B16.5 Class 150 bolt pattern, and rated for the design pressure of the line at the design temperature.
Thermoplastic Flange Constructionradio
○ One-piece solid flange
○ Two-piece flange with a loose ring over a stub end
NOTE A one-piece flange is the simpler and stronger component, and once it is solvent cemented or fused on, its bolt holes are where they are, so the mating flange has to be rotated to meet it. A two-piece flange carries a loose ring that turns on the stub end, so bolt holes align without rotating a run of rigid pipe, and it is selected wherever a flange is made up against an item of equipment or a valve whose bolt pattern cannot be moved. (10.1.2)
10.1.3 Flange gaskets on plastic flanges shall be full faced, conforming to ASME B16.21, of the material indicated in the datasheet.
Plastic Flange Gasket Materialselect
EPDM
Fluoroelastomer (FKM)
Expanded polytetrafluoroethylene
Polytetrafluoroethylene envelope over an elastomer core
Neoprene
Nitrile
Derived — the chemical, concentration, and design temperature of each line on the piping schedule and the gasket manufacturer's chemical resistance data (by default)
10.1.4 Full-face gaskets shall be used on every plastic flange, and ring gaskets shall not be used on a plastic flange.
NOTE A ring gasket inside the bolt circle of a plastic flange loads the flange as a lever: the bolts pull the outer edge down while the gasket holds the inner edge up, and the flange cracks across the bolt holes. A full-face gasket distributes the bolt load across the whole face so the flange is in compression everywhere. (10.1.5)
10.1.6 Flange bolts shall be tightened in a crossing pattern in at least three passes to the torque published by the flange manufacturer, with a flat washer under every bolt head and nut bearing on plastic, and bolts shall not be used to pull misaligned flanges together.
10.1.7 Where a plastic flange mates to a metallic raised-face flange, the raised face shall be removed, a flat-face flange substituted, or a spacer ring of the raised-face height installed outside the gasket, so that the plastic flange bears on a flat surface.

10.2 Transition Fittings

10.2.1 Every connection between plastic piping and metallic piping, a valve, or an item of equipment shall be made with a transition fitting rated for the design pressure at the design temperature, of the type indicated in the datasheet.
Transition Fitting at Plastic-to-Metallic Connectionsselect
Flanged (plastic flange or polyethylene flange adapter to a metallic flange)
Mechanical joint adapter
Restrained transition coupling
NOTE A flanged transition is the one that comes apart for maintenance, is made in every material, and is the usual connection at a valve or a pump; it takes the most space and costs the most per joint. A mechanical joint adapter fuses or cements to the plastic pipe and presents a ductile iron mechanical joint to the metallic side, which is the natural transition on a buried yard main to a ductile iron valve or fitting. A restrained transition coupling joins two plain ends of different outside diameters with a single sleeve and is selected for repairs and for exposed connections where neither side carries a flange. (10.2.2)
10.2.3 Where plastic pipe is joined to metallic pipe by a threaded transition, the plastic component shall carry the male thread.
10.2.4 Transition fittings on polyethylene pipe shall be restrained, and the polyethylene side shall be fitted with an internal stiffener where the fitting grips the outside of the pipe.
10.2.5 The weight and the thermal movement of the metallic piping, valve, or equipment on one side of a transition shall be supported and anchored independently so that neither is carried by the plastic piping.
NOTE A cast iron valve body hung from the PVC line it is cemented into is the single most common cause of a cracked plastic fitting in a chemical room. The plastic can carry the fluid; it cannot carry the valve. (10.2.6)

11 Double-Containment Piping

11.1 Containment Construction

11.1.1 Double containment shall be provided on the lines designated for it on the piping schedule.
11.1.2 Double-containment piping shall be a factory-engineered system in which the carrier pipe, the containment pipe, the support spacers, the fittings, and the termination and closure fittings are the products of one manufacturer, designed as a system for the carrier material and the containment material selected.
11.1.3 The carrier pipe of a double-containment line shall comply with every requirement of this standard for its material as if it were a single-wall line.
11.1.4 The containment pipe material shall be as indicated in the datasheet.
Containment Pipe Materialselect
PVC
Clear PVC
CPVC
Polyethylene
Polypropylene
PVDF
FRP
Not applicable (no double-containment piping on the project)
NOTE The containment pipe meets the chemical only when the carrier has failed, so it is selected for resistance over the hours or days until the leak is found rather than for the design life, which is why a containment pipe is often a less costly material than its carrier. Containment in the same material as the carrier fuses or cements with the same tooling and lets the carrier and containment joints be made by one crew; a dissimilar containment, polyethylene around PVDF or PVC around CPVC, pairs the carrier the chemical needs with the containment the budget allows and requires a system engineered for the two materials' different expansion. Clear PVC containment lets a leak be seen through the wall and is selected for exposed chemical room runs where a sensor system is not justified. (11.1.5)
11.1.6 The containment pipe shall be rated for not less than the design pressure of the carrier pipe unless the piping schedule indicates a lower containment design pressure for the line.
11.1.7 The annular space shall be sized by the system manufacturer for the carrier pipe's thermal expansion and for free drainage to the leak detection points, and support spacers shall hold the carrier concentric without restraining its axial movement.
11.1.8 Carrier pipe joints shall be made, inspected, and pressure tested under this standard before the containment pipe is closed over them.
NOTE A carrier joint closed inside its containment before it is tested is a joint that cannot be seen again. The containment system makes a carrier leak survivable; it does not make it findable, and a carrier that leaks on the day it is filled empties into the annulus and announces itself as a containment failure. (11.1.9)
11.1.10 Where the carrier and containment pipe are of the same material, the containment joint shall be of the same type as the carrier joint, and closure fittings shall be the system manufacturer's split or slip-over closures engineered for the joint.
11.1.11 Fittings in a double-contained line shall be contained fittings of the same system, and single-wall fittings shall not be inserted between contained runs.

11.2 Leak Detection

11.2.1 The leak detection method for double-containment piping shall be as indicated in the datasheet.
Containment Leak Detection Methodselect
Low-point leak sensors with an alarm panel
Continuous sensing cable in the annulus with an alarm panel
Pressure or vacuum monitoring of a sealed annulus with an alarm panel
Visual inspection at termination fittings and clear containment, without sensors
Not applicable (no double-containment piping on the project)
NOTE A low-point sensor detects liquid where the annulus drains to it, so it depends on the containment being pitched and on every low point having a sensor, and it tells the operator that a leak exists but not where. A continuous sensing cable runs the full length of the annulus and locates the leak to within a few feet, at a higher cost per foot and with a cable that has to be replaced after it is wetted by some chemicals. Pressure or vacuum monitoring of a sealed annulus detects a breach of either wall, including a containment breach that would let a leak escape, and it is the method of underground fuel systems carried over to chemical lines that are buried or inaccessible; it needs a gas-tight annulus and closure fittings rated for it. Visual inspection through clear containment or at termination sight glasses is the least costly method and relies on an operator walking the line, which suits a short exposed run inside a chemical room and nothing buried. (11.2.2)
11.2.3 Leak detection sensors shall be located at every low point of the annulus, at every termination fitting, and at the intervals the system manufacturer publishes for the sensor type, and the locations shall be shown on the coordination drawings.
11.2.4 Leak detection sensors and the sensing cable shall be of materials rated for the chemical in the carrier pipe.
11.2.5 The leak detection panel shall annunciate each sensor individually by location, and the alarm shall be reported as indicated in the datasheet.
Containment Leak Alarm Reportingselect
Dry contact per zone to the plant control system
Networked leak detection panel on the plant control network
Local audible and visual alarm at the panel only
11.2.7 The leak detection panel enclosure shall be of the rating indicated in the datasheet.
Leak Detection Panel Enclosureselect
Type 1
Type 12
Type 4
Type 4X
Type 3R
NOTE A leak detection panel is installed in or next to the chemical room its piping serves, and a chemical room is a corrosive, washdown environment whatever the drawings call it, which is why Type 4X is the norm for this one panel even though the plant's other control panels are Type 12. Type 1 and Type 12 are selected where the panel sits in a dry electrical room away from the chemical, and Type 3R where it is mounted outdoors at a buried line's termination. (11.2.8)
11.2.9 A leak detection panel installed in a chemical feed room, a washdown area, or outdoors shall be rated Type 4X regardless of the datasheet selection.
11.2.10 The leak detection system shall be commissioned by wetting or actuating every sensor in turn and confirming the alarm at the panel and at the plant control system, and the result shall be recorded in the commissioning report.

11.3 Annulus Termination and Drainage

11.3.1 The annulus shall be pitched continuously toward its leak detection and drain points at not less than 1/8 in. per foot unless the system manufacturer publishes a lesser slope for the sensor type.
11.3.2 Each annulus shall be terminated at both ends with the system manufacturer's termination fitting, with a drain valve at each low point that discharges to a point where the leaked chemical can be collected without exposure to personnel.
11.3.3 The annulus of a contained line in a chemical service that off-gasses shall be vented at its high point through the termination fitting to a location indicated on the process and instrumentation diagrams.
NOTE An annulus is a closed volume between two pipes, and the chemical that leaks into it has the same vapor pressure it had in the carrier. A sealed annulus on a hypochlorite line builds the same pressure the carrier would, which is why the annulus is vented where the chemical off-gasses, and why the vent has to go somewhere the gas can be tolerated. (11.3.4)

12 Exposed Installation

12.1 Support Interface

12.1.1 Hanger and support hardware, structural attachments, and seismic bracing for plastic process piping shall be furnished and installed in accordance with Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current adopted revision.sync/hangers-and-supports and MSS SP-58.
12.1.2 Horizontal plastic piping shall be supported at intervals not exceeding the pipe manufacturer's published spacing for the material, size, wall, and design temperature, with the fluid specific gravity of the line taken into account.
12.1.3 Continuous support of horizontal plastic piping shall be provided as indicated in the datasheet.
Continuous Support of Horizontal Plastic Pipingselect
Required for all sizes NPS 1 and smaller
Required for all sizes in chemical service
Required where the published spacing at the design temperature is less than 4 ft
Not required where the published spacing is met
NOTE Small plastic pipe sags between hangers at any spacing a hanger crew will tolerate, and sag in a chemical line pockets the chemical, pockets gas, and loads the solvent joints in bending, so many plants carry everything NPS 1 and smaller in a continuous channel or angle. Requiring continuous support for every chemical line removes the spacing calculation from every heat-traced and sun-exposed run at the cost of a channel under all of it. A threshold on the published spacing puts continuous support only where the derated spacing has become impractical, and relying on the published spacing alone is the least costly policy where the piping is large, cool, and short. (12.1.4)
12.1.5 Hangers in contact with plastic pipe shall have a bearing width not less than the pipe manufacturer publishes, shall have no sharp edges, and shall not compress, clamp, or point-load the pipe.
12.1.6 Plastic pipe shall not be supported from a fitting, a flange, or a valve, and a valve or other concentrated load on a plastic line shall be supported independently on both sides.
12.1.7 Where a hanger must allow the pipe to move axially for thermal expansion, it shall be a guide or a sliding support that does not grip the pipe, and the hanger shall not be used as an anchor unless it is designated as one on the expansion layout.
12.1.8 Where the parties disagree whether a support arrangement is adequate for a plastic line, the Engineer of Record shall make the initial determination.

12.2 Thermal Expansion

12.2.1 Thermal expansion of every exposed plastic run shall be accommodated by the method indicated in the datasheet, at the locations shown on the expansion layout submitted under this standard.
Expansion Compensation Method for Exposed Plastic Pipingselect
Offsets and changes of direction
Fabricated expansion loops
Expansion joints rated for the pipe material and the chemical service
NOTE Plastic pipe expands several times more than steel for the same temperature change: PVC about 3 × 10⁻⁵ in. per inch per °F and polyethylene about 1 × 10⁻⁴, so a 100 ft PVC line that warms 50°F grows about 1.8 in. and the same line in polyethylene about 6 in. An offset or a change of direction absorbs the growth in the bending of the legs and costs nothing beyond the fittings already in the run, which is why it is the method of first resort wherever the routing already turns. A fabricated loop is the same mechanism added to a straight run that does not turn. An expansion joint absorbs the movement in a bellows or a piston, takes the least space, introduces an elastomer or a sliding seal into the chemical service, and needs anchors and guides on both sides to make it work. (12.2.2)
12.2.3 Anchors and guides shall be installed at the locations shown on the expansion layout, and shall not be relocated or omitted without the written approval of the Engineer of Record.
12.2.4 Expansion joints in plastic piping shall be rated by their manufacturer for the pipe material, the design pressure and temperature, the chemical service, and the movement at the location, and shall be installed with the guides and anchors the manufacturer requires.
12.2.5 Plastic piping shall not be anchored at both ends of a straight run without expansion compensation between the anchors.

12.3 Ultraviolet and Weather Protection

12.3.1 Plastic piping exposed to sunlight after installation shall be protected by the method indicated in the datasheet.
Ultraviolet Protection of Exposed Outdoor Plastic Pipingselect
Pipe compound rated by its manufacturer for ultraviolet exposure
Field-applied coating under the high-performance coatings standard
Insulation with a weatherproof jacket
Not applicable (no plastic piping exposed to sunlight)
NOTE Sunlight degrades the surface of unprotected PVC and CPVC: the pipe chalks, loses impact resistance, and over years loses wall. Polyethylene compounded with carbon black and the ultraviolet-rated grades of the other materials carry their own protection and need nothing more, which is the simplest selection where the material already has it. A field-applied coating under High Performance CoatingsHigh-Performance CoatingsResolves to the current adopted revision.sync/high-performance-coatings protects PVC and CPVC and has to be a latex or acrylic that the pipe manufacturer accepts, because a solvent-borne coating attacks the pipe. Insulation with a jacket protects the pipe, keeps the fluid cooler than a sun-exposed bare pipe, and is the selection where the line needs insulation or heat tracing in any case. (12.3.2)
12.3.3 Field-applied coatings on plastic pipe shall be of a type the pipe manufacturer accepts for the material, and solvent-borne coatings shall not be applied to PVC or CPVC.
12.3.4 Plastic piping shall be protected from open flame, hot work, welding spatter, and contact with heated surfaces during and after installation.

12.4 Freeze Protection

12.4.1 Exposed plastic piping that can fall below 35°F and holds liquid shall be freeze protected by heat tracing under Electric Heat TracingElectric Heat TracingResolves to the current adopted revision.sync/electric-heat-tracing and insulation under Mechanical InsulationMechanical InsulationResolves to the current adopted revision.sync/mechanical-insulation, or shall be drained for the season, as shown on the process mechanical plans.
12.4.2 Heat tracing on plastic pipe shall be a self-regulating cable whose maximum sheath temperature is below the pipe manufacturer's maximum continuous temperature for the material, applied over the aluminum foil tape the cable manufacturer requires on plastic pipe.
NOTE A constant-wattage cable on a plastic pipe keeps heating when the pipe stops conducting the heat away, and a PVC line heat traced with a cable rated for steel has been found softened and sagging between hangers. The foil tape spreads the cable's heat around the circumference of a material that conducts it poorly, which is why the tape is part of the installation rather than an option. (12.4.3)
12.4.4 Where heat tracing raises the pipe wall temperature, the pressure rating of the line shall be derated at the maximum sheath temperature of the cable.

12.5 Penetrations and Sleeves

12.5.1 Plastic piping passing through a wall, floor, or slab that does not retain liquid shall pass through a sleeve with a modular mechanical seal or a sealed annulus, with the pipe centered and independently supported on both sides so that it does not bear on the sleeve.
12.5.2 Plastic piping passing through a water-retaining concrete wall or floor shall connect to a flanged wall pipe with a waterstop collar furnished under Ductile Iron Process PipingDuctile Iron Process PipingResolves to the current adopted revision.sync/ductile-iron-process-piping or Steel And Stainless Process PipingSteel and Stainless Steel Process PipingResolves to the current adopted revision.sync/steel-and-stainless-process-piping, and the plastic pipe shall not itself be cast into a liquid-retaining wall.
NOTE A plastic pipe cast into a concrete wall is restrained by the concrete at the point it expands most, and the bond between the plastic and the concrete is the leak path through the wall. The metallic wall pipe with its collar is cast in, restrained, and sealed by the concrete; the plastic line flanges to it on each face. (12.5.3)
12.5.4 The annular space at a penetration through a fire-resistance-rated assembly shall be closed with a firestop system listed for the plastic pipe material, size, and annular dimension, furnished under FirestoppingFirestoppingResolves to the current adopted revision.sync/firestopping.
12.5.5 Modular seals and sleeve seals at penetrations in chemical service shall be of an elastomer rated for the chemical in the line.

12.6 Valve, Equipment, and Identification Interfaces

12.6.1 Rubber-seated butterfly valves and eccentric plug valves in plastic process piping shall be furnished under Butterfly ValvesButterfly ValvesResolves to the current adopted revision.sync/butterfly-valves and Eccentric Plug ValvesEccentric Plug ValvesResolves to the current adopted revision.sync/eccentric-plug-valves, and every other valve type shall be furnished under the standard governing it on the valve schedule; process check valves shall be furnished under Process Check ValvesProcess Check ValvesResolves to the current adopted revision.sync/process-check-valves; thermoplastic ball, diaphragm, and check valves for chemical service are not yet owned by a SynC standard and shall be as indicated on the valve schedule until one exists.
12.6.2 The piping shall provide a removable flanged or union connection on each side of every valve and at every item of equipment so that the component can be removed without cutting pipe.
12.6.3 Connections to chemical feed equipment, metering pumps, and calibration columns shall be made at the equipment connection shown on the process and instrumentation diagrams, and the equipment itself is outside this standard.
12.6.4 Pipe markers, flow direction arrows, and valve tags shall be furnished and installed under Mechanical IdentificationMechanical IdentificationResolves to the current adopted revision.sync/mechanical-identification and ASME A13.1, and the legend on every chemical line shall state the chemical name and its concentration.
12.6.5 Field painting of exposed plastic piping, where required for identification or ultraviolet protection, shall be performed under High Performance CoatingsHigh-Performance CoatingsResolves to the current adopted revision.sync/high-performance-coatings with a coating the pipe manufacturer accepts.

13 Buried Installation

13.1 Trench, Bedding, and Embedment

13.1.1 Buried thermoplastic pressure piping shall be installed in accordance with ASTM D2774, buried PVC pressure pipe in accordance with AWWA C605, buried polyethylene pipe in accordance with AWWA M55, and buried FRP pipe in accordance with ASTM D3839.
13.1.2 Trench excavation, dewatering, shoring, and backfill above the pipe zone shall be performed under EarthworkEarthworkResolves to the current adopted revision.sync/earthwork, and this standard governs the pipe zone from the trench bottom to 12 in. above the top of the pipe.
13.1.3 Embedment material in the pipe zone shall be of the class indicated in the datasheet, as classified in ASTM D2321.
Pipe Zone Embedment Material Class (ASTM D2321)select
Class I, angular crushed stone
Class II, clean sand and gravel
Class III, coarse-grained soil with fines
NOTE Crushed stone gives the stiffest side support with the least compaction effort and drains, so it is the embedment for wet trenches and for the larger, more flexible pipes whose deflection is controlled by the soil; it also has the sharp edges that gouge a plastic pipe if it is dumped on it. Clean sand and gravel compact to a uniform support that does not point-load the pipe and are the embedment most yard piping is laid in. A coarse soil with fines is often the native material, costs least, and reaches its support stiffness only when compacted at the right moisture, which a wet trench does not allow. (13.1.4)
13.1.5 Embedment shall be placed and compacted in lifts on both sides of the pipe simultaneously to the density indicated in the datasheet, and shall be worked under the haunches of the pipe by hand or with hand-guided equipment.
Pipe Zone Embedment Compactionrange
% of standard Proctor maximum dry density
859095
13.1.6 The trench bottom shall be shaped or bedded so that the pipe bears uniformly along its length and not on the bells, couplings, or flanges, with bell holes excavated at each joint.
13.1.7 Rock, debris, frozen material, and organic material shall not be placed within the pipe zone, and embedment shall not be dropped onto the pipe from the trench edge.
13.1.8 The deflection of buried flexible pipe 12 in. and larger shall not exceed five percent of the inside diameter when measured after backfill is complete, and a run exceeding that deflection shall be re-excavated and re-embedded at the Contractor's cost.

13.2 Depth of Cover and Buoyancy

13.2.1 Buried plastic piping shall be installed with not less than the depth of cover indicated in the datasheet, measured from finished grade to the top of the pipe.
Depth of Cover over Buried Plastic Pipingrange
in.
12182430364248607296
Derived — Frost DepthFrost DepthParameterEach project supplies its own value.frost-depth and the surface loading on the yard piping routes (by default)
NOTE Cover does two jobs: it keeps the pipe below the depth the ground freezes to, and it spreads a wheel load before it reaches the pipe. The first is a fact about the site, the second a fact about where the trench runs, and together they determine the cover rather than leaving it to a project-wide number. A plastic pipe under a plant roadway needs the cover that keeps truck loading within its deflection limit, and the same pipe in a lawn needs only to clear the frost. (13.2.2)
13.2.3 Where the required cover cannot be achieved, the pipe shall be protected by a casing, a concrete cap, or insulation as shown on the yard piping plan, and shall not be installed with less cover without the Engineer of Record's written approval.
13.2.4 Where any portion of buried plastic piping lies below Seasonal High Groundwater ElevationSeasonal High Groundwater ElevationParameterEach project supplies its own value.seasonal-high-groundwater-elevation, the pipe shall be weighted, backfilled, or filled with water before dewatering is discontinued so that the empty pipe does not float.
NOTE An empty polyethylene or PVC pipe is lighter than the water it displaces, and a 24 in. main in a flooded trench lifts its embedment and comes up through the backfill. The pipe does not float once the backfill above it weighs more than its buoyancy, which is why the sequence of backfill and dewatering is a requirement and not a site preference. (13.2.5)

13.3 Thrust Restraint

13.3.1 Thrust at every fitting, valve, and change in direction in buried piping with gasketed or mechanical joints shall be restrained by the method indicated in the datasheet.
Thrust Restraint for Buried Gasketed and Mechanical Jointsradio
○ Restrained joints
○ Concrete thrust blocks
NOTE A restrained joint carries the thrust through the pipe wall to the soil friction along a calculated length on each side of the fitting, so it needs no concrete, does not depend on undisturbed soil behind the fitting, and leaves the trench free for the next utility; it costs more per joint and the restrained length has to be calculated and installed. A thrust block transfers the thrust to undisturbed soil through a mass of concrete poured against the fitting, costs little, and fails when a later excavation removes the soil it bears on or when the soil was never as stiff as assumed. (13.3.2)
13.3.3 Where restrained joints are selected, the restrained length on each side of each fitting shall be calculated for the test pressure, the soil, and the depth of cover in accordance with AWWA M23 for PVC and AWWA M55 for polyethylene, and the calculation shall be submitted under this standard.
13.3.4 Where thrust blocks are selected, they shall bear against undisturbed soil, shall be sized for the test pressure and the soil bearing value, and shall be formed so that concrete does not encase the joint or the bolts.
13.3.5 Fused polyethylene and solvent-cemented joints are self-restrained, and thrust restraint shall be provided only at their transitions to gasketed or mechanical joints and at the fittings on those joints.

13.4 Tracer Wire and Warning Tape

13.4.1 Tracer wire shall be installed on buried plastic piping as indicated in the datasheet.
Tracer Wire on Buried Plastic Pipingradio
● Required on every buried plastic run
○ Not required
13.4.2 Where tracer wire is required, it shall be 12 AWG copper-clad steel with high-density polyethylene insulation not less than 30 mils thick, laid along the top of the pipe, spliced only with waterproof connectors made for tracer wire, and brought to grade at every valve box, structure wall, and the end of every run in a test station.
13.4.3 Tracer wire continuity shall be tested over the full length of every run after backfill and before acceptance, and a run without continuity shall be excavated and repaired at the Contractor's cost.
NOTE A plastic pipe cannot be located from the surface by any instrument, so the tracer wire is the only record of where the line is once the trench is closed. A splice made with a wire nut and tape corrodes open in a season, and a wire that was buried with the pipe and never brought to grade cannot be connected to a locator. (13.4.4)
13.4.5 Detectable warning tape shall be installed 12 in. above the top of every buried plastic run, with the legend naming the fluid in the line.

14 Pressure Testing

14.1 Test Medium and Pressure

14.1.1 Every portion of the plastic process piping shall be hydrostatically tested with clean water before it is insulated, buried, enclosed in containment, or concealed.
14.1.2 Compressed air or any other gas shall not be used to pressure test thermoplastic piping.
14.1.3 The hydrostatic test pressure shall be the multiple of the design pressure indicated in the datasheet, and shall not exceed 1.5 times the pressure rating of the lowest-rated component in the boundary at the test temperature.
Hydrostatic Test Pressurerange
× design pressure
11.251.5
NOTE A test at 1.5 times the design pressure is what ASME B31.3 requires and what the waterworks standards for PVC and polyethylene expect, so it is the norm. The multiple is lowered where a component in the boundary cannot take it and cannot be isolated, and the test is then a test of that component's rating rather than of the design pressure; a lower multiple is a decision the schedule records, not a field adjustment. (14.1.4)
14.1.5 Where the calculated test pressure exceeds the rating of a component within the intended boundary, that component shall be isolated or removed from the boundary and tested separately at its own rated pressure.
14.1.6 Solvent-cemented piping shall not be tested until every joint in the boundary has cured for the time the cement manufacturer publishes for the pipe size, the ambient temperature, and the test pressure.
14.1.7 Polyethylene piping shall be tested in accordance with ASTM F2164, with the initial expansion phase completed and make-up water added before the test phase begins, and the total time at test pressure shall not exceed the limit that standard sets.
NOTE Polyethylene expands under pressure for the first hours of a test, so the pressure falls and water has to be added before the drop means anything; ASTM F2164 separates that expansion phase from the test phase and sets the make-up water a sound system is allowed during the test. A polyethylene test read like a steel test fails every sound line. (14.1.8)
14.1.9 Buried piping shall be tested with the joints exposed and the pipe barrel partially backfilled to hold it in place, and the trench shall not be fully backfilled over a joint until the test boundary containing it has passed.
14.1.10 A test boundary shall not include a section of double-containment piping whose carrier test has not been completed and recorded.

14.2 Test Procedure and Acceptance

14.2.1 The boundary shall be filled from its lowest point with air vented continuously from every high point until the boundary is full of water, and the test pressure shall be applied and held for not less than the duration indicated in the datasheet.
Test Hold Durationrange
hours
124824
Default: Not less than 2 hours
14.2.2 A solvent-cemented, fused, bonded, or flanged boundary shall show no pressure loss and no visible leakage over the hold period.
14.2.3 A buried boundary with gasketed joints shall show no visible leakage, and the make-up water added to restore the test pressure shall not exceed the allowance calculated under AWWA C605 for the length, diameter, and test pressure of the boundary.
NOTE A fused, cemented, or bonded joint is a continuous wall, and a boundary made of them either holds or has a joint that did not fuse, cement, or bond, which is why zero loss is the criterion. A gasketed joint seats under pressure and weeps a measurable but tiny volume across the elastomer, and the waterworks allowance exists to keep that weep from failing a sound main. (14.2.4)
14.2.5 Every joint, fitting, flange, and transition within the boundary shall be visually inspected during the hold period, and visible leakage at any joint shall fail the test regardless of the measured loss.
14.2.6 A failed test shall be followed by repair of the cause, restoration of the boundary, the cure or cooling time of the repair, and a complete repeat of the test from the beginning.
14.2.7 A leaking solvent-cemented joint shall be cut out and remade with a coupling, and shall not be repaired by applying cement to the outside of the joint.
14.2.8 The Contractor shall bear the cost of the repair, the retest, the test water, and the repair of any other trade's work damaged by the failure or by the water released.
14.2.9 Test gauges shall be calibrated within the preceding twelve months, shall have a full-scale range between 1.5 and 2 times the test pressure, and shall be graduated finely enough to resolve a change of 2 psi.
14.2.10 The test gauge shall be located at the low point of the boundary, and the temperature of the test water shall be recorded at the start and end of the hold on any boundary exposed to sunlight.
NOTE A plastic pipe in the sun warms its contents through the hold, and the pressure rises or falls with the water temperature rather than with a leak. Recording the temperature is what lets the reading be interpreted; a gauge in the shade at the low point is what keeps the reading honest. (14.2.11)

14.3 Testing of Double-Containment Piping

14.3.1 The carrier pipe of a double-contained line shall be tested under this standard with the containment open at every carrier joint, and the carrier test shall be recorded before any containment closure is made.
14.3.2 The containment pipe shall be tested hydrostatically after closure at the containment design pressure, with the carrier depressurized, and shall show no pressure loss and no leakage at any closure fitting or termination over the hold period.
14.3.3 Where pressure or vacuum monitoring of the annulus is selected, the annulus shall additionally be proved gas-tight at the monitoring pressure for the duration the system manufacturer publishes.
14.3.4 The annulus shall be drained and dried after the containment test, and every leak detection sensor shall be confirmed dry and in its normal state before the line is placed in service.

14.4 Test Documentation

14.4.1 The pressure test shall be witnessed by the party indicated in the datasheet.
Pressure Test Witnessselect
Engineer of Record or the Engineer's representative
Owner's commissioning authority
Authority Having Jurisdiction inspector
Contractor's quality control representative
NOTE The Engineer of Record's representative is the witness on most plant projects because the test is the one acceptance act on a piping system that cannot be inspected afterward, and the record has to satisfy the engineer who signs the project off. An Owner's commissioning authority is the witness where the Owner runs a formal commissioning program that includes piping. The Authority Having Jurisdiction witnesses where a permit condition requires it, typically on a potable line. A Contractor's quality control representative is the witness where the Owner has accepted a contractor-run quality program, and the record then stands on that program. (14.4.2)
14.4.3 The Contractor shall give the witnessing party not less than three business days' notice of a scheduled test.
14.4.4 A signed and dated test report shall be prepared for every test boundary, recording the date, the boundary, the pipe material and joint type, the test pressure, the hold duration, the starting and ending pressure, the make-up water added where an allowance applies, the water temperature where required, and the names and signatures of the Contractor's representative and the witness.
14.4.5 A test report shall not record a conditional or qualified pass, and a boundary in which a repair was made shall be recorded on a new report covering the complete repeat test.

15 Disinfection of Plant Potable Water Piping

15.1 Every plastic line within the plant that will carry finished or potable water shall be disinfected in accordance with AWWA C651 after it has passed its pressure test and before it is placed in service.
NOTE Disinfection of building domestic water piping inside plant buildings is governed by Disinfection Of Water SystemsDisinfection of Domestic Water SystemsResolves to the current adopted revision.sync/disinfection-of-water-systems, and this section applies to the plant process and yard piping that carries finished water. (15.2)
15.3 The disinfection method shall be as indicated in the datasheet.
Disinfection Method for Plant Potable Linesselect
Continuous-feed method
Slug method
Tablet method
Not applicable (no plant potable or finished-water lines in plastic)
NOTE The continuous-feed method fills the line with chlorinated water at a controlled concentration and holds it, and it is the method for a main that can be filled from one end and isolated, which describes most plant yard piping. The slug method moves a high-concentration slug through a long line that cannot be held full for the contact time, and it is selected for long or large mains where the chlorinated water volume of the continuous method is impractical. The tablet method places hypochlorite tablets in the pipe as it is laid and is the simplest for a short line that is laid clean and filled slowly, and it is unavailable where the line cannot be kept dry and clean during installation. (15.4)
15.5 The disinfecting agent, its concentration, and the contact time shall be those AWWA C651 prescribes for the method selected, and the Contractor shall record the free chlorine residual at the start and the end of the contact period.
15.6 Chlorinated water shall be flushed from the line to a point of disposal indicated on the yard piping plan and shall be dechlorinated in accordance with AWWA C655 before it reaches any watercourse, storm drain, or treatment process not designed to receive it.
15.7 Bacteriological samples shall be collected and analyzed as AWWA C651 requires for the method selected, and the line shall not be placed in service until the results are satisfactory and have been submitted under this standard.
15.8 A line that fails bacteriological clearance shall be re-disinfected and re-sampled at the Contractor's cost.

16 Delivery, Storage, and Handling

16.1 Pipe, fittings, and containment components shall be delivered with the manufacturer's markings intact and legible, and with the ends capped or covered.
16.2 Pipe shall be stored on continuous supports or on the manufacturer's dunnage spacing, stacked no higher than the manufacturer publishes, and shall not be stored where it bears on a point, a fitting, or a bell.
16.3 PVC, CPVC, and FRP pipe stored outdoors for more than the period the manufacturer publishes shall be covered with an opaque, ventilated cover that keeps the pipe out of direct sunlight without trapping heat.
16.4 Plastic pipe shall not be dragged over the ground, dropped, or struck, and pipe with a gouge deeper than ten percent of the wall thickness, a crack, or a chalked surface shall be rejected.
NOTE A gouge in a polyethylene or PVC pipe is a stress concentration the pipe carries for its life, and the standards set the ten percent limit because a deeper gouge in a pressure pipe grows under sustained stress until it is a crack. The dragged pipe looks fine from the trench edge and the gouge is on the side that was down. (16.5)
16.6 Solvent cements, primers, adhesives, resins, and gaskets shall be stored within the temperature range their manufacturer publishes, away from heat and open flame, and shall not be used after their marked expiration date.
16.7 FRP pipe and fittings shall be handled with slings or padded supports and shall not be lifted with hooks, chains, or cables in contact with the laminate.
16.8 Fusion machines and heater plates shall be protected from contamination and shall be stored with the heater surfaces covered.
16.9 Open pipe ends shall be capped or covered whenever work on them is not in progress.
16.10 The Contractor shall bear the cost of replacing material that was damaged or degraded by improper storage or handling.

17 Warranty

17.1 The Contractor shall warrant the plastic process piping work, including pipe, fittings, flanges, every joint of every type, transition fittings, containment piping, and the leak detection system, against defects in materials and workmanship for the period indicated in the datasheet, measured from the date of substantial completion.
Contractor Installation Warranty Periodrange
years
1235
Default: Not less than 1 years
17.2 Where the contract General Conditions specify a longer warranty period than the datasheet, the longer period shall govern.
17.3 Any leak, joint failure, cracking, or chemical attack attributable to a material or installation defect discovered within the warranty period shall be repaired by the Contractor at no cost to the Owner.
17.4 The Contractor shall bear the cost of excavating, draining, decontaminating, and reinstating the work required to reach a warranted repair, and the cost of repairing damage caused by the failure or by the repair itself.
NOTE A warranted repair on a chemical line carries a cost no mechanical warranty names: the line has to be drained and flushed before anyone can work on it, and the chemical that leaked has to be cleaned up. Naming those costs here is what keeps the warranty from being argued over the one thing that makes a chemical line different. (17.5)
17.6 A repaired or replaced portion of the piping shall carry a warranty running for a full new term from the date the repair is accepted, or for the remainder of the original term, whichever ends later.
17.7 The Contractor shall pressure test any repaired portion in accordance with this standard before the repair is accepted.

18 Spare Parts

18.1 The Contractor shall furnish the spare parts indicated in the datasheet, delivered to the Owner before substantial completion, packaged, labeled with the line and material they serve, and listed on a receipt signed by the Owner's representative.
Spare Parts Furnishedcheckbox
☑ One full set of flange gaskets for each gasket material and size installed
☑ One leak detection sensor of each type installed
☐ Solvent cement and primer, one unopened container of each type, within shelf life
☐ Two couplings of each size and material for repair of solvent-cemented lines
☐ One electrofusion coupling of each polyethylene size installed

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