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SynC · Editorial revision

Domestic Water Piping

Revision7
EditedAug 29, 2026
StatusCurrent
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Current revision. This is editorial revision 7, the current text of this standard. Read it on the standard's page.

SynC Standards Team — Specifier (Platform Standards) ✓ OfficialDiscloses employment SynC (SynC Platform Team)
Neutrality remake batch: from-scratch field derivation with project parameters and derived fields

1 Scope

NOTE This standard governs the piping that carries potable water through a building — the pipe and tube itself, the fittings and joints that connect it, the valves and specialties installed in the line, and everything that supports, insulates, protects, tests, and disinfects it. (1.1)
NOTE The scope begins at the discharge connection of the building water service assembly and ends at the stop, union, or rough-in connection serving each fixture and each item of equipment. (1.2)
NOTE The following are governed elsewhere and are outside this standard: (1.3)
  • the water service, the meter assembly, and the backflow assembly protecting the building supply
  • water heating equipment, storage vessels, master mixing valves, thermal expansion vessels, and the recirculation pump with its controls and its balancing devices at the equipment
  • the fixtures, faucets, stops, supplies, and fixture-mounted temperature limiting devices the system serves
  • water softening, filtration, and chemical treatment equipment installed as a treatment train
  • fire protection piping, hydronic piping, sanitary drainage and vent piping, and laboratory and process water piping
  • site water mains outside the building footprint, exterior irrigation distribution, and exterior site hydrants
1.4 Pipe sizes, routing, riser arrangement, and fixture rough-in dimensions shall be as indicated on the plumbing plans, riser diagrams, and rough-in schedules.
NOTE This standard sets what the piping must be and what it must do; the drawings set where it goes and how large it is. (1.5)
1.6 Every component of the piping system that contacts potable water shall be certified to NSF/ANSI/CAN 61 for health effects.
1.7 Every pipe, fitting, valve, solder, flux, gasket, lubricant, and appurtenance that contacts potable water shall be certified to NSF/ANSI/CAN 372 for lead content.
NOTE The NSF/ANSI/CAN 372 limit of 0.25 percent lead as a weighted average of the wetted surfaces is a federal requirement under the Reduction of Lead in Drinking Water Act and shall not be waived at the project level. (1.8)

2 Referenced Standards

2.1 Materials, components, 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 Authority Having Jurisdiction, or two referenced standards impose conflicting requirements, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
2.3 The adopted plumbing code shall take precedence over every other reference on any matter that code addresses directly.
Standard Title
IPC International Plumbing Code
UPC Uniform Plumbing Code
IBC International Building Code
IECC International Energy Conservation Code
ASHRAE 90.1 Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings
ASHRAE 188 Legionellosis: Risk Management for Building Water Systems
ASCE 7 Minimum Design Loads and Associated Criteria for Buildings and Other Structures
NFPA 70 National Electrical Code
ASME B31.9 Building Services Piping
ASME A13.1 Scheme for the Identification of Piping Systems
ASME B16.18 Cast Copper Alloy Solder Joint Pressure Fittings
ASME B16.22 Wrought Copper and Copper Alloy Solder Joint Pressure Fittings
ASME B16.26 Cast Copper Alloy Fittings for Flared Copper Tubes
ASME B16.51 Copper and Copper Alloy Press-Connect Pressure Fittings
ASTM B88 Seamless Copper Water Tube
ASTM B32 Solder Metal
ASTM B813 Liquid and Paste Fluxes for Soldering Applications of Copper and Copper Alloy Tube
ASTM B828 Making Capillary Joints by Soldering of Copper and Copper Alloy Tube and Fittings
AWS A5.8/A5.8M Filler Metals for Brazing and Braze Welding
ASTM D2846/D2846M Chlorinated Poly(Vinyl Chloride) Plastic Hot- and Cold-Water Distribution Systems
ASTM F441/F441M Chlorinated Poly(Vinyl Chloride) Plastic Pipe, Schedules 40 and 80
ASTM F442/F442M Chlorinated Poly(Vinyl Chloride) Plastic Pipe, SDR-PR
ASTM F437 Threaded Chlorinated Poly(Vinyl Chloride) Plastic Pipe Fittings, Schedule 80
ASTM F438 Socket-Type Chlorinated Poly(Vinyl Chloride) Plastic Pipe Fittings, Schedule 40
ASTM F439 Socket-Type Chlorinated Poly(Vinyl Chloride) Plastic Pipe Fittings, Schedule 80
ASTM F493 Solvent Cements for Chlorinated Poly(Vinyl Chloride) Plastic Pipe and Fittings
ASTM F876 Crosslinked Polyethylene Tubing
ASTM F877 Crosslinked Polyethylene Hot- and Cold-Water Distribution Systems
ASTM F1807 Metal Insert Fittings Utilizing a Copper Crimp Ring for SDR9 PEX and PE-RT Tubing
ASTM F1960 Cold Expansion Fittings with PEX Reinforcing Rings for Use with PEX and PE-RT Tubing
ASTM F2080 Cold-Expansion Fittings with Metal Compression-Sleeves for PEX and PE-RT Pipe
ASTM F2098 Stainless Steel Clamps for Securing SDR9 PEX Tubing to Metal Insert Fittings
ASTM F2159 Plastic Insert Fittings Utilizing a Copper Crimp Ring for SDR9 PEX Tubing
ASTM F1281 Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene Pressure Pipe
ASTM F2434 Metal Insert Fittings for SDR9 Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene Pipe
ASTM F2769 Polyethylene of Raised Temperature Plastic Hot- and Cold-Water Tubing and Distribution Systems
ASTM F2389 Pressure-Rated Polypropylene Piping Systems
ASTM A312/A312M Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
ASTM A269/A269M Seamless and Welded Austenitic Stainless Steel Tubing for General Service
ASTM A53/A53M Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless
ASTM E84 Surface Burning Characteristics of Building Materials
ASTM C547 Mineral Fiber Pipe Insulation
ASTM C534/C534M Preformed Flexible Elastomeric Cellular Thermal Insulation in Sheet and Tubular Form
ASTM C552 Cellular Glass Thermal Insulation
ASTM C591 Unfaced Preformed Rigid Cellular Polyisocyanurate Thermal Insulation
ASTM C1136 Flexible Low Permeance Vapor Retarders for Thermal Insulation
ASTM C1729 Aluminum Jacketing for Insulation
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
ASSE 1010 Water Hammer Arresters
ASSE 1061 Push-Fit Fittings
ASSE 1079 Dielectric Pipe Unions
PDI WH 201 Water Hammer Arresters
MSS SP-58 Pipe Hangers and Supports — Materials, Design, Manufacture, Selection, Application, and Installation
MSS SP-67 Butterfly Valves
MSS SP-69 Pipe Hangers and Supports — Selection and Application
MSS SP-80 Bronze Gate, Globe, Angle, and Check Valves
MSS SP-110 Ball Valves Threaded, Socket-Welding, Solder Joint, Grooved and Flared Ends
AWWA C651 Disinfecting Water Mains
AWWA C105/A21.5 Polyethylene Encasement for Ductile-Iron Pipe Systems
IEEE 515.1 Testing, Design, Installation, and Maintenance of Electrical Resistance Heat Tracing for Commercial Applications

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following for review before any piping material is procured:
  • product data for each pipe and tube furnished, giving the material, the ASTM designation, the wall series or dimension ratio, the pressure and temperature rating, and the potable-contact certification
  • product data for each fitting and joining component, giving the material, the ASME or ASTM designation, the pressure and temperature rating, and the potable-contact certification
  • product data for each valve, giving the body, trim, seat, and stem seal materials, the pressure and temperature rating, the end connections, the operator, and the potable-contact certification
  • product data for the water hammer arrestors, giving the certification listing, the size designation, and the rated discharge capacity in fixture units
  • product data for the pipe insulation, giving the thermal conductivity at the mean service temperature, the flame spread and smoke developed indices, the water vapor permeance of the facing or jacket, the service temperature range, and the jacketing proposed for each location
  • product data for the hangers, supports, guides, anchors, saddles, and insulation protection shields, with the attachment method proposed for each structure type
  • product data for the dielectric fittings and transition couplings proposed at each dissimilar-material joint
  • product data for the temperature maintenance heat trace, giving the output rating, the maximum circuit length, the control method, and the electrical characteristics
  • shop drawings of the expansion loops, offsets, anchors, and guides, showing the movement each provision accommodates
  • shop drawings of the hot water return piping showing each branch balancing device and the flow it is to be set to
  • a valve schedule listing every valve by tag number, service, size, type, and location
Action Submittal Packagecheckbox
☐ Pipe and tube product data
☐ Fitting and joining component product data
☐ Valve product data
☐ Water hammer arrestor product data
☐ Pipe insulation product data
☐ Hanger and support product data
☐ Dielectric fitting product data
☐ Temperature maintenance heat trace product data
☐ Expansion provision shop drawings
☐ Hot water return balancing shop drawings
☐ Valve schedule
3.1.2 Piping fabrication and installation shall not begin until the corresponding action submittals have been reviewed and returned.

3.2 Informational Submittals

3.2.1 The Contractor shall submit the following supporting calculations and records with, or before, the action submittals:
  • the pipe sizing calculation, identifying the sizing method used and the demand it is based on
  • an evaluation of the incoming water analysis against the published water chemistry limits of every piping material proposed
  • the water hammer arrestor sizing calculation for each protected fixture group
  • the insulation thickness determination for each service and pipe size, citing the governing table or the calculation performed
  • the condensation control determination for cold water piping in each space where the design dew point exceeds the calculated pipe surface temperature
  • seismic restraint calculations sealed by a registered design professional, or the pre-approved restraint detail the Contractor intends to use with its listing identified
  • the qualification records of every person who will make brazed, fusion, or press joints
  • written confirmation from the pipe manufacturer that each sealant, adhesive, coating, firestop material, and insulation adhesive proposed for use in contact with plastic piping is compatible with that piping
  • the proposed flushing, disinfection, and bacteriological sampling procedure, with the sample points identified
Informational Submittal Packagecheckbox
☐ Pipe sizing calculation
☐ Water chemistry evaluation
☐ Water hammer arrestor sizing calculation
☐ Insulation thickness determination
☐ Condensation control determination
☐ Seismic restraint calculations or pre-approved detail
☐ Joining personnel qualification records
☐ Plastic piping chemical compatibility confirmation
☐ Flushing and disinfection procedure

3.3 Closeout Submittals

3.3.1 The Contractor shall submit the following before the domestic water system is accepted:
  • as-built drawings recording the installed routing and the location of every valve, drain, arrestor, air vent, expansion provision, and access panel, with the valve tag numbers as fitted
  • operation and maintenance manuals for the valves, arrestors, heat trace, and specialties furnished, with the recommended maintenance tasks and their intervals tabulated
  • the valve chart, framed under glass or rigid laminate, listing every valve by tag number, service, and location
  • pressure test reports for every test section, recording the test medium, the test pressure, the start and end times, the gauge readings, the gauge identification number and calibration date, and the result, signed by the person who witnessed the test
  • flushing and disinfection reports recording the disinfectant used, the dose, the contact time, the residual measured at each sample point, and the final flush result
  • the certified laboratory report for every bacteriological sample taken
  • warranty documentation for each product carrying a manufacturer warranty, identifying the coverage period and the date coverage begins
  • a signed receipt from the Owner for the spare parts delivered
Closeout Submittal Packagecheckbox
☐ As-built drawings with valve tag numbers
☐ Operation and maintenance manuals
☐ Framed valve chart
☐ Pressure test reports
☐ Flushing and disinfection reports
☐ Certified bacteriological laboratory reports
☐ Warranty documentation
☐ Spare parts receipt

4 Quality Assurance

4.1 Installer Qualifications

4.1.1 Piping work shall be performed by personnel holding the license the Authority Having Jurisdiction requires for that trade in the jurisdiction where the work is performed.
4.1.2 Brazed joints shall be made only by personnel qualified in the brazing procedure being used, and the qualification records shall be on site before brazing begins.
4.1.3 Heat fusion joints shall be made only by personnel who have completed the pipe manufacturer's training for the fusion method and equipment being used.
4.1.4 Press and cold expansion joints shall be made only by personnel who have completed the fitting manufacturer's training for the tool and fitting system being used.
4.1.5 The Contractor shall keep the tools used to make press, crimp, clamp, cold expansion, and fusion joints within the calibration or service interval the tool manufacturer publishes, and shall keep the calibration records on site.

4.2 Product Marking and Certification

4.2.1 Every length of pipe and tube shall carry a continuous, legible marking giving the manufacturer, the material designation, the size, the wall series or dimension ratio, the applicable ASTM designation, and the potable-contact certification mark.
4.2.2 Every fitting shall carry a legible marking giving the manufacturer, the material or alloy designation, the size, the applicable standard, and the potable-contact certification mark.
4.2.3 Material that does not carry the required markings shall not be incorporated into the work.
4.2.4 The Contractor shall keep the certification listings for every potable-contact product on site for the duration of the work.
4.2.5 The Contractor shall make the certification listings available for inspection by the Authority Having Jurisdiction, the Engineer of Record, and the Owner's representative on request.

4.3 Inspection and Concealment

4.3.1 The rough piping, the pressure test, and the disinfection shall each be made available for inspection by the Authority Having Jurisdiction before the next stage of work proceeds.
4.3.2 Piping shall not be concealed, insulated, backfilled, or covered until the inspections applicable to that portion of the work are complete and the work has been released.
4.3.3 Work concealed before the applicable inspection is complete shall be uncovered at the Contractor's cost, and the concealing construction shall be reinstated at the Contractor's cost.

5 Water Chemistry and Service Conditions

5.1 Incoming Water Chemistry

NOTE Every candidate piping material has a published water chemistry envelope, and the same supply that is benign for one material can be aggressive to another: soft, low-alkalinity, low-pH water attacks copper; high chloride attacks austenitic stainless steel; free chlorine and chloramine oxidize the inner wall of some polymers over time; and hardness deposits scale on whatever surface runs hottest. (5.1.1)
5.1.2 The Engineer of Record shall establish the design water chemistry from Site Water Supply SourceSite Water Supply SourceParameterEach project supplies its own value.site-water-supply-source and Site Water Supply HardnessSite Water Supply HardnessParameterEach project supplies its own value.site-water-supply-hardness.
5.1.3 The Contractor shall evaluate the incoming water analysis against the published water chemistry limits of every piping material proposed and shall report any exceedance before that material is ordered.
5.1.4 The Contractor shall not be held responsible for material failure caused by water chemistry outside the pipe manufacturer's published limits where the exceedance was reported under this article and the piping was installed as specified.
NOTE Treatment equipment installed to condition the incoming supply is the subject of a separate standard and is not furnished under this standard. (5.1.5)

5.2 Incoming Water Temperature

NOTE The coldest incoming water temperature sets the lowest surface temperature the cold water piping will reach, and that surface temperature is what condensation control is designed against. (5.2.1)
5.2.2 Cold water piping shall be evaluated for condensation using a pipe surface temperature derived from Site Water Supply Temperature MinimumSite Water Supply Temperature MinimumParameterEach project supplies its own value.site-water-supply-temperature-minimum and the design dew point of each space the piping passes through.

5.3 Ambient Conditions Along the Route

5.3.1 The Contractor shall identify every portion of the route that passes through an unconditioned space, an exterior wall cavity, a ventilated attic, a crawl space, a loading dock, or any other location subject to freezing.
5.3.2 Piping in those locations shall be freeze-protected as specified in this standard.
5.3.3 The Contractor shall identify every portion of the route exposed to direct sunlight or to artificial ultraviolet sources.
5.3.4 Polymer piping in those locations shall be shielded from ultraviolet exposure or shall be a material listed for continuous ultraviolet exposure.

6 System Pressure and Flow Velocity

6.1 Pressure Control

NOTE The pressure the utility delivers is a site fact, not a design choice, and it is often well above what fixtures, appliance fill valves, and pipe joints are rated to see continuously. (6.1.1)
6.1.2 The pressure reducing arrangement for the building shall be as indicated in the datasheet.
Pressure Reducing Arrangementselect
None because the supply pressure is within the permitted range
A single pressure reducing valve on the building supply
Parallel pressure reducing valves sized for high and low demand
A pressure reducing valve on the building supply with additional zone valves on upper floors
Zone pressure reducing valves only
Derived — Site Water Supply Pressure MaximumSite Water Supply Pressure MaximumParameterEach project supplies its own value.site-water-supply-pressure-maximum compared against the maximum static pressure the adopted plumbing code permits at a fixture supply (by default)
6.1.3 Where a pressure reducing valve is provided, the assembly shall include an isolation valve upstream, a strainer upstream, an isolation valve downstream, a pressure gauge downstream, and a union or flange permitting removal of the valve without cutting pipe.
6.1.4 The system working pressure downstream of the pressure reducing arrangement shall be as indicated in the datasheet.
System Working Pressurerange
psi
2030405060657080100125150160
NOTE Closing the building supply with a pressure reducing valve, a check valve, or a backflow assembly turns the system into a closed vessel, and water heated in a closed vessel raises system pressure until something relieves it. (6.1.5)
NOTE Thermal expansion control for the closed system is provided under Water HeatersCommercial Water HeatersResolves to the current adopted revision.sync/water-heaters and is not furnished under this standard. (6.1.6)
6.1.7 Air vent valves shall be provided at every high point of the distribution piping that cannot be purged through a fixture outlet.

6.2 Flow Velocity Limits

NOTE Velocity is the design lever that governs erosion at fittings, the strength of the pressure wave a fast-closing valve produces, and how much noise the pipe radiates into the space around it; the limit that governs at a given point is whichever of those three is most sensitive there. (6.2.1)
NOTE In copper tube, sustained high velocity strips the protective oxide film at elbows, tees, and partly closed valves, and hot water is more aggressive in this respect than cold, which is why the hot water limit is the lower one. (6.2.2)
6.2.3 The maximum design velocity in cold water piping shall be as indicated in the datasheet.
Maximum Design Velocity — Cold Waterrange
ft/s
23456781012
6.2.4 The maximum design velocity in hot water supply piping shall be as indicated in the datasheet.
Maximum Design Velocity — Hot Water Supplyrange
ft/s
234567810
6.2.5 The maximum design velocity in hot water return piping shall be as indicated in the datasheet.
Maximum Design Velocity — Hot Water Returnrange
ft/s
123456
6.2.6 The maximum design velocity in piping serving or passing through acoustically sensitive spaces shall be as indicated in the datasheet.
Maximum Design Velocity — Acoustically Sensitive Areasrange
ft/s
1234568
6.2.7 The spaces to which the acoustically sensitive velocity limit applies shall be as indicated on the plumbing plans.

6.3 Pipe Sizing Basis

6.3.1 The basis on which the distribution piping is sized shall be as indicated in the datasheet.
Pipe Sizing Basisselect
The fixture unit method in the adopted plumbing code
A statistical peak demand analysis
A measured or metered demand profile for a comparable facility
A process or equipment demand schedule established by the Owner
NOTE The fixture unit tables in the plumbing codes were built on fixture flow rates far higher than current water-conserving fixtures deliver, so on a building full of low-flow fixtures the fixture unit method returns larger pipe than the demand justifies, and oversized pipe lengthens the time water sits in the building. (6.3.2)
6.3.3 Where the sizing basis produces a size smaller than the adopted plumbing code minimum for that fixture or branch, the code minimum shall govern.

7 Distribution Arrangement

7.1 The distribution arrangement shall be as indicated in the datasheet.
Distribution Arrangementselect
Trunk and branch with tees taken off a main
Central manifold with an individual run to each fixture
Remote submanifolds fed from a main, with individual runs to the fixtures each submanifold serves
Trunk and branch mains with submanifolds serving fixture groups
NOTE A trunk-and-branch arrangement puts fittings inside the wall and ceiling cavities and shares a main between fixtures; a manifold arrangement moves the fittings to one accessible location and gives every fixture its own uninterrupted run, at the cost of more total tubing and a dedicated space for the manifold. (7.2)
NOTE Smaller individual runs also hold less water, so the volume that must be purged before hot water arrives at a fixture is lower on a manifold arrangement than on a branch of the same length. (7.3)
7.4 Where a manifold or submanifold arrangement is used, the manifold shall be installed in an accessible location and shall be provided with an isolating valve on each outlet port.
7.5 Where a manifold or submanifold arrangement is used, each outlet port shall be permanently labeled with the fixture it serves.
7.6 Manifold locations shall be as indicated on the plumbing plans.
7.7 The manifold material shall be as indicated in the datasheet.
Manifold Materialselect
Copper
Cast or forged copper alloy
Stainless steel
Engineered polymer listed for potable water

7.8 Dead Legs and Stagnation

NOTE Water that is not moved does not stay potable: disinfectant residual decays, biofilm establishes on the pipe wall, and in the warm part of the temperature band the organisms that colonize building water systems multiply. (7.8.1)
7.8.2 Branches serving fixtures that are removed, capped, or taken out of service shall be cut back to the active main and capped at the main.
7.8.3 Branch piping serving a fixture shall not exceed the maximum length the datasheet indicates between the active main and the fixture outlet.
Maximum Branch Length from an Active Main to a Fixture Outletrange
ft
24681015202530405060
7.8.4 Capped stub-outs provided for future fixtures shall be valved at the main and shall be left drained.

8 Piping Material Selection by Service

NOTE Cold water distribution, hot water supply, hot water return, and buried or below-slab piping each see a different combination of temperature, duty cycle, and external environment, so each is selected on its own rather than inheriting one building-wide answer. (8.1)
NOTE Every piping material offered in this standard is permitted by the model plumbing codes for potable water distribution in at least some jurisdictions, and the adopted code and the Authority Having Jurisdiction determine which of them may be used on a given project. (8.2)
8.3 The cold water distribution piping material shall be as indicated in the datasheet.
Cold Water Distribution Piping Materialselect
Copper tube
CPVC
PEX
PE-RT
PEX-AL-PEX
Polypropylene
Stainless steel
Galvanized steel
8.4 The hot water supply piping material shall be as indicated in the datasheet.
Hot Water Supply Piping Materialselect
Copper tube
CPVC
PEX
PE-RT
PEX-AL-PEX
Polypropylene
Stainless steel
8.5 The hot water return piping material shall be as indicated in the datasheet.
Hot Water Return Piping Materialselect
The same material as the hot water supply piping
Copper tube
CPVC
PEX
PE-RT
Polypropylene
Stainless steel
NOTE Hot water return piping runs hot continuously and moves water the whole time, whereas the supply piping is hot but largely still between draws, so the return sees the higher time-at-temperature and the higher cumulative flow of the two. (8.6)
8.7 The hot water return piping material shall be rated for continuous service at the maximum return temperature the system is controlled to.
8.8 The buried and below-slab piping material shall be as indicated in the datasheet.
Buried and Below-Slab Piping Materialselect
Copper tube
Copper tube with a continuous polyethylene encasement
PEX in a continuous sleeve
PE-RT in a continuous sleeve
CPVC
Polypropylene
Stainless steel
NOTE Piping under a slab or in soil is reached only by breaking the floor, so the material choice there is being made against a repair cost the same failure would not carry above the ceiling. (8.9)
8.10 Where two different materials are used on the same system, the transition shall be made with a fitting listed for that specific combination.
8.11 The Engineer of Record shall confirm that every material selected is permitted by the adopted plumbing code for the service, the location, and the pipe sizes involved.

9 Copper Tube and Copper Alloy Fittings

9.1 Copper Tube

9.1.1 Requirements in this section apply where the datasheet selects copper tube for a service.
9.1.2 Copper water tube shall conform to ASTM B88.
NOTE ASTM B88 tube is made in three wall series that share the same outside diameter: Type K is the heaviest, Type L is intermediate, and Type M is the lightest, so the same fittings serve all three and the choice is a wall thickness and pressure rating decision rather than a dimensional one. (9.1.3)
9.1.4 The copper tube wall series for above-ground piping shall be as indicated in the datasheet.
Copper Tube Wall Series — Above-Ground Pipingselect
Type K
Type L
Type M
9.1.5 The copper tube wall series for buried and below-slab piping shall be as indicated in the datasheet.
Copper Tube Wall Series — Buried and Below-Slab Pipingselect
Type K
Type L
9.1.6 The copper tube temper shall be as indicated in the datasheet.
Copper Tube Temperselect
Drawn temper in straight lengths
Annealed temper in coils
Drawn temper above grade and annealed temper below grade
NOTE Annealed tube bends without fittings and can be pulled through a slab or trench in a continuous length, which removes the buried joints; drawn tube is stiffer, holds a straight line between supports, and carries a higher rated working pressure in the same wall series. (9.1.7)
9.1.8 Type M tube shall be used only where the adopted plumbing code permits it for the service and the location in which it is installed.
9.1.9 Copper tube shall not be used where the water analysis falls outside the pH, alkalinity, or dissolved oxygen limits published for copper without the corrosion control measures the Engineer of Record directs.

9.2 Copper Alloy Fittings

9.2.1 The copper fitting type shall be as indicated in the datasheet.
Copper Fitting Typeselect
Wrought copper solder joint fittings to ASME B16.22
Cast copper alloy solder joint fittings to ASME B16.18
Press-connect fittings to ASME B16.51
Flared fittings to ASME B16.26
Grooved mechanical couplings listed for copper tube
Push-fit fittings listed to ASSE 1061
NOTE Wrought fittings are drawn from tube stock and hold a tighter socket tolerance than cast fittings, which affects capillary fill on a soldered joint; cast fittings are made in configurations that cannot be drawn, so the two are commonly used together on the same system. (9.2.2)
9.2.3 Fittings shall carry a pressure and temperature rating not less than that of the tube they join.
9.2.4 Cast copper alloy fittings shall be a dezincification-resistant alloy where the water analysis indicates dezincification potential.
9.2.5 Press-connect fittings shall carry a sealing element listed for the service temperature of the piping in which they are installed.
9.2.6 Press-connect fittings shall incorporate a feature that causes an unpressed joint to leak visibly at the test pressure.
NOTE Without that feature, an unpressed joint can hold static pressure through the test and separate later under a surge or a thermal cycle. (9.2.7)
9.2.8 Push-fit fittings shall be listed to ASSE 1061 and shall be installed only where the joint remains accessible.
9.2.9 Flared joints shall be made only in annealed tube.

10 CPVC Pipe, Tubing, and Fittings

10.1 CPVC Pipe and Fittings

10.1.1 Requirements in this section apply where the datasheet selects CPVC for a service.
10.1.2 The CPVC dimension system shall be as indicated in the datasheet.
CPVC Dimension Systemselect
Copper tube size tubing to ASTM D2846
Iron pipe size Schedule 40 pipe to ASTM F441/F441M
Iron pipe size Schedule 80 pipe to ASTM F441/F441M
Iron pipe size SDR-PR pipe to ASTM F442/F442M
NOTE Copper tube size CPVC is made in sizes through 2 in. and iron pipe size CPVC continues above that, so a building with mains larger than 2 in. will normally carry both dimension systems and needs a transition fitting where they meet. (10.1.3)
10.1.4 CPVC fittings shall conform to ASTM D2846 for copper tube size systems, to ASTM F438 for Schedule 40 socket fittings, to ASTM F439 for Schedule 80 socket fittings, and to ASTM F437 for Schedule 80 threaded fittings.
10.1.5 PVC pipe, PVC fittings, and PVC solvent cement shall not be used in a CPVC system.
NOTE CPVC and PVC fittings are visually similar and are stocked side by side, so the marking on the fitting is the only reliable way to tell them apart at the point of installation. (10.1.6)
10.1.7 The pressure rating of CPVC falls as temperature rises, and the published rating at the system's maximum operating temperature shall be used rather than the rating at 73°F.
10.1.8 CPVC piping shall not be operated above the maximum continuous service temperature published for the dimension system installed.
10.1.9 CPVC shall not be installed in a location exposed to direct sunlight or to an artificial ultraviolet source unless it is shielded by an opaque covering or coated with a product the pipe manufacturer lists for that purpose.

10.2 CPVC Chemical Compatibility

NOTE CPVC is susceptible to environmental stress cracking from contact with incompatible plasticizers and solvents, and the products that cause it are ordinary construction materials — some firestop sealants, some pipe thread compounds, some spray-applied insulation and adhesives, some cutting oils, and some leak detection sprays. (10.2.1)
NOTE A stress-cracking failure typically appears weeks or months after installation, at a fitting shoulder where the residual stress is highest, so the contact that caused it is usually concealed by then. (10.2.2)
10.2.3 The Contractor shall obtain written confirmation from the CPVC manufacturer that each sealant, adhesive, coating, firestop material, thread compound, insulation product, and leak detection product proposed for use in contact with the piping is compatible with CPVC.
10.2.4 Products for which that confirmation is not obtained shall not be used in contact with, or adjacent to, CPVC pipe and fittings.
10.2.5 Where an incompatible product has contacted CPVC pipe or fittings, the affected pipe and fittings shall be removed and replaced at the Contractor's cost.

11 PEX and PE-RT Tubing and Fittings

11.1 PEX and PE-RT Tubing

11.1.1 Requirements in this section apply where the datasheet selects PEX, PE-RT, or PEX-AL-PEX for a service.
11.1.2 PEX tubing shall conform to ASTM F876 and shall be furnished as a system conforming to ASTM F877.
11.1.3 PE-RT tubing shall conform to ASTM F2769.
11.1.4 PEX-AL-PEX pipe shall conform to ASTM F1281.
NOTE PEX is crosslinked by one of three production methods — peroxide, silane, or irradiation — and all three meet ASTM F876; they differ in the degree of crosslinking, in how much expansion memory the tube retains, and therefore in which fitting systems the tube can be used with. (11.1.5)
11.1.6 The PEX crosslinking method shall be as indicated in the datasheet.
PEX Crosslinking Methodselect
Peroxide crosslinked, designated PEX-a
Silane crosslinked, designated PEX-b
Irradiation crosslinked, designated PEX-c
Not applicable because PE-RT is selected
11.1.7 Cold expansion fittings rely on the tube recovering its shape after being stretched, so a tube used with that fitting system shall be one the fitting manufacturer lists for it.
11.1.8 The chlorine resistance classification of the tubing shall be as indicated in the datasheet.
Tubing Chlorine Resistance Classificationselect
Class 1 end use
Class 3 end use
Class 5 end use
NOTE The end use classification printed on the tube states the combination of temperature, pressure, and disinfectant exposure the tube is rated for over its design life, so it is the marking that governs whether a given tube may carry recirculated hot water. (11.1.9)
11.1.10 Tubing selected for hot water supply or hot water return service shall carry an end use classification covering continuous service at the maximum system temperature.
11.1.11 PEX, PE-RT, and PEX-AL-PEX shall not be installed in a location exposed to direct sunlight or to an artificial ultraviolet source beyond the exposure period the tube manufacturer publishes.
11.1.12 Tubing shall not be installed where the surface temperature can exceed the maximum the tubing is rated for, including locations adjacent to flues, vents, recessed luminaires, and uninsulated hot piping.
11.1.13 Tubing shall be installed with the bend radius the manufacturer publishes, and a bend support shall be used where the routing requires a tighter radius.
11.1.14 A kinked section shall be cut out and replaced, and shall not be repaired by heating and re-rounding unless the tube manufacturer publishes that repair for the specific product.

11.2 PEX and PE-RT Mechanical Fittings

11.2.1 The fitting system shall be as indicated in the datasheet.
PEX and PE-RT Fitting Systemselect
Cold expansion with a reinforcing ring to ASTM F1960
Cold expansion with a metal compression sleeve to ASTM F2080
Metal insert with a copper crimp ring to ASTM F1807
Plastic insert with a copper crimp ring to ASTM F2159
Metal insert with a stainless steel clamp to ASTM F2098
Metal insert fittings to ASTM F2434 for PEX-AL-PEX
Push-fit fittings listed to ASSE 1061
NOTE A cold expansion joint is made by stretching the tube and a reinforcing ring over the fitting and letting the material recover onto it, which leaves the full tube bore at the fitting; an insert joint places the fitting body inside the tube and squeezes a ring down onto it, which reduces the bore at each fitting by the wall thickness of the insert. (11.2.2)
11.2.3 Fitting bodies shall be a dezincification-resistant alloy, a polymer listed for the service, or stainless steel where the water analysis indicates dezincification potential.
11.2.4 Fittings, rings, sleeves, and tools shall be used only in the combinations the fitting manufacturer lists.
11.2.5 A tool from one fitting system shall not be used to make a joint in another fitting system.
11.2.6 Joints made with a tool and fitting combination the manufacturer does not list shall be cut out and remade at the Contractor's cost.
11.2.7 Crimp and clamp joints shall be verified with the go/no-go gauge the tool manufacturer supplies, and the gauge shall be applied to every joint.
11.2.8 A tool that fails the gauge check shall be removed from service until it has been recalibrated, and every joint made since the last successful check shall be re-gauged.
11.2.9 Cold expansion joints shall be allowed to recover fully before the assembly is moved or loaded.
NOTE Recovery time lengthens as ambient temperature falls, and a joint disturbed before it has recovered will not develop its full grip. (11.2.10)
11.2.11 PEX, PE-RT, and PEX-AL-PEX shall not be joined by solvent cement, adhesive, or threading.

12 Polypropylene Pipe and Fittings

12.1 Requirements in this section apply where the datasheet selects polypropylene for a service.
12.2 Polypropylene pipe and fittings shall conform to ASTM F2389.
12.3 The polypropylene pipe construction shall be as indicated in the datasheet.
Polypropylene Pipe Constructionselect
Solid wall
Faser composite with a fiber-reinforced middle layer
Multilayer with an aluminum middle layer
NOTE The fiber-reinforced and aluminum-layered constructions carry a lower coefficient of thermal expansion than solid wall pipe, which changes how much movement the routing has to absorb on a long hot run. (12.4)
12.5 Polypropylene joints shall be made by socket fusion, butt fusion, or electrofusion using the equipment and the time and temperature parameters the pipe manufacturer publishes.
12.6 The fusion method shall be as indicated in the datasheet.
Polypropylene Fusion Methodselect
Socket fusion
Butt fusion
Electrofusion
Socket fusion in smaller sizes and butt fusion in larger sizes
NOTE A fusion joint is a homogeneous weld rather than a mechanical seal, so it has no gasket or sealing element to age, and it also cannot be disassembled or adjusted after it is made. (12.7)
12.8 Fusion joints shall be made only at ambient temperatures within the range the pipe manufacturer publishes for the fusion method being used.
12.9 Fusion joints shall be allowed to cool undisturbed for the period the pipe manufacturer publishes before the assembly is moved or loaded.
12.10 Transitions from polypropylene to threaded or flanged connections shall be made with the manufacturer's transition fittings incorporating a metal insert.
12.11 Polypropylene shall not be installed in a location exposed to direct sunlight or to an artificial ultraviolet source unless the pipe carries a factory ultraviolet-protective layer or is shielded by an opaque covering.

13 Stainless Steel Pipe and Fittings

13.1 Requirements in this section apply where the datasheet selects stainless steel for a service.
13.2 Stainless steel pipe shall conform to ASTM A312/A312M and stainless steel tubing shall conform to ASTM A269/A269M.
13.3 The stainless steel grade shall be as indicated in the datasheet.
Stainless Steel Gradeselect
Type 304
Type 304L
Type 316
Type 316L
A duplex grade listed for potable water
NOTE The molybdenum in Type 316 raises its resistance to chloride pitting relative to Type 304, so on a supply with elevated chloride the two grades behave differently in service even though both are austenitic stainless. (13.4)
NOTE The low-carbon grades reduce carbide precipitation in the heat-affected zone, which matters where joints are welded and matters much less where they are pressed or grooved. (13.5)
13.6 The stainless steel joining method shall be as indicated in the datasheet.
Stainless Steel Joining Methodselect
Press-connect fittings listed for stainless steel
Orbital or manual gas tungsten arc welding with an inert backing gas
Grooved mechanical couplings listed for stainless steel
Threaded and flanged connections
13.7 Welded joints shall be made with an inert backing gas maintained inside the pipe until the weld has cooled below the temperature at which oxidation occurs.
NOTE A weld made without backing gas forms an oxide scale on the inside of the joint that both roughens the surface and depletes chromium locally, which is where crevice corrosion starts. (13.8)
13.9 Welded joints shall be cleaned of heat tint and passivated after welding.
13.10 Sealing elements in press-connect and grooved stainless steel joints shall be listed for the service temperature and for potable water contact.
13.11 Stainless steel shall not be brought into contact with carbon steel tools, brushes, or wool, and tools used on stainless steel shall be dedicated to stainless steel.
NOTE Iron particles embedded from carbon steel tooling rust on the stainless surface and initiate pitting under the rust deposit. (13.12)

14 Galvanized Steel Pipe

14.1 Requirements in this section apply where the datasheet selects galvanized steel piping, or where existing galvanized steel piping is extended, altered, or tied into.
14.2 Where galvanized steel is selected or extended, the pipe shall conform to ASTM A53/A53M, Type E or Type S, hot-dip galvanized, and shall carry the potable-contact certification.
14.3 Where galvanized steel is selected or extended, fittings shall be galvanized malleable iron or galvanized cast iron carrying the potable-contact certification.
14.4 Where galvanized steel is selected or extended, threads shall be cut clean and full, and the thread compound or tape shall carry the potable-contact certification.
14.5 Where galvanized steel is selected or extended, cut ends shall be reamed to full bore before assembly.
14.6 Where galvanized steel is joined to copper or to a copper alloy, a dielectric separation shall be provided as specified in this standard.
NOTE The zinc coating protects the steel sacrificially and is consumed over time, at a rate that depends on the water chemistry and the temperature; hot water lines consume it faster than cold, and once the coating is gone the exposed steel corrodes and the corrosion product reduces the bore. (14.7)
14.8 Where an existing galvanized system is being extended, the Contractor shall report the internal condition of the existing pipe at each tie-in point before the connection is made.

15 Dissimilar Material Transitions

NOTE Two different metals in contact with a common electrolyte form a galvanic cell, and the less noble metal corrodes preferentially at the junction; the water in the pipe is the electrolyte, so the cell operates on the inside of the joint where nothing can be seen. (15.1)
15.2 A dielectric separation shall be provided at every joint between copper or a copper alloy and a ferrous material.
15.3 The dielectric separation method shall be as indicated in the datasheet.
Dielectric Separation Methodselect
Dielectric unions listed to ASSE 1079
Dielectric flange kits with an insulating gasket, sleeves, and washers
A dielectric nipple with an inert internal lining
A brass or copper alloy nipple of sufficient length to separate the metals
15.4 Dielectric fittings shall be rated for the pressure and temperature of the service in which they are installed.
15.5 Dielectric fittings shall be installed in an accessible location.
NOTE The insulating components of a dielectric fitting are the part that wears out, and a fitting concealed in a chase cannot be replaced without opening the construction around it. (15.6)
15.7 Transitions between plastic and metal piping shall be made with a fitting the pipe manufacturer lists for that transition.
15.8 A threaded plastic male adapter shall not be threaded into a metal female fitting where the manufacturer's instructions call for the opposite arrangement.
NOTE Threading a plastic male end into a metal socket puts the plastic in hoop tension as the joint is tightened, and that is where a threaded plastic adapter splits. (15.9)

16 Valves

16.1 Valve Certification and Construction

16.1.1 Every valve installed in potable water service shall be certified to NSF/ANSI/CAN 61 and NSF/ANSI/CAN 372 across every wetted surface, including the body, the trim, the seat, the stem seal, and the packing.
16.1.2 Valves shall carry a pressure and temperature rating not less than that of the piping in which they are installed.
16.1.3 Valve end connections shall be compatible with the piping material in which the valve is installed and shall be made by a method this standard permits for that material.
16.1.4 Valves in hot water and hot water return service shall carry seat and seal materials rated for continuous service at the maximum system temperature.
16.1.5 Copper alloy valve bodies shall be a dezincification-resistant alloy where the water analysis indicates dezincification potential.

16.2 Isolation Valves

16.2.1 The isolation valve type for sizes 2 in. and smaller shall be as indicated in the datasheet.
Isolation Valve Type — 2 in. and Smallerselect
Full port ball valve with a copper alloy body
Full port ball valve with a stainless steel body
Full port ball valve with a polymer body listed for potable water
Gate valve to MSS SP-80
Globe valve to MSS SP-80
16.2.2 The isolation valve type for sizes 2-1/2 in. and larger shall be as indicated in the datasheet.
Isolation Valve Type — 2-1/2 in. and Largerselect
Full port ball valve
Lug or grooved body butterfly valve to MSS SP-67
Wafer body butterfly valve to MSS SP-67
Resilient seated gate valve
Gate valve to MSS SP-80
NOTE A quarter-turn valve reaches full closure in one motion and holds its seat by compression, while a multi-turn valve closes gradually and can be throttled; the quarter-turn motion is also what makes a hand-closed quarter-turn valve capable of generating a surge on a long run. (16.2.3)
NOTE A gate valve left in one position for long periods can seize on its stem or corrode at the wedge seating faces, and a gate valve held part-open erodes at the seat faces where the flow accelerates past the partly withdrawn wedge. (16.2.4)
16.2.5 Butterfly valves shall be installed with the straight pipe upstream and downstream that the valve manufacturer publishes.
16.2.6 Butterfly valves 6 in. and larger, and butterfly valves in any size where the differential pressure exceeds the manual operating limit, shall be furnished with a gear operator.
16.2.7 Valves 2-1/2 in. and larger shall be furnished with a means of locking the valve in position.
16.2.8 Isolation valves shall be provided at each of the following locations, and additional isolation valves shall be provided where indicated on the valve schedule:
  • immediately downstream of the building water service assembly
  • at the base of each riser and at the top of each downfeed riser
  • at the take-off of each branch main from a riser or a horizontal main
  • at the inlet and the outlet of each item of equipment connected to the system
  • at each manifold and at each outlet port of a manifold
  • at the branch serving each group of fixtures within a single tenant space, restroom group, or department
  • at each fixture, where the adopted plumbing code requires a fixture stop
  • on the hot water return at each branch take-off and at each riser base
NOTE The fixture stops, supplies, and escutcheons at the fixture connection are furnished under Plumbing FixturesPlumbing FixturesResolves to the current adopted revision.sync/plumbing-fixtures; this standard governs the branch piping up to that connection. (16.2.9)
16.2.10 Isolation valves concealed in construction shall be provided with an access panel sized to permit operation and removal of the valve.
16.2.11 Access panel locations shall be as indicated on the architectural drawings and the plumbing plans.

16.3 Check Valves

16.3.1 The check valve type shall be as indicated in the datasheet.
Check Valve Typeselect
Spring loaded center guided silent check valve
Dual plate wafer check valve
Swing check valve to MSS SP-80
Lift check valve
In-line spring check cartridge
NOTE A spring loaded check begins to close as soon as flow decelerates, so the disc is nearly seated when flow reverses; a swing check waits for reverse flow to move the disc, and the disc slams into the seat against a column of water that is already moving backward. (16.3.2)
16.3.3 Check valves shall be provided at each pump discharge and at each point where reverse flow could carry water from one system or one zone into another.
16.3.4 Check valves shall be installed in the orientation the valve manufacturer publishes.
16.3.5 Check valves shall not be installed immediately downstream of an elbow, a tee, or a valve unless the valve manufacturer publishes that arrangement.

16.4 Drain and Vent Valves

16.4.1 The drain valve type shall be as indicated in the datasheet.
Drain Valve Typeselect
Full port ball valve with a hose thread outlet and a cap
Hose bibb with a cap
Stop and waste valve
16.4.2 Drain valves shall be provided at every low point of the system and at every zone, branch, riser, or section that can be isolated and cannot drain back through the main.
16.4.3 Drain valve outlets shall be furnished with a cap or plug secured to the valve.
16.4.4 Automatic air vents installed on potable water piping shall be certified for potable water contact and shall discharge to a location where a discharge will be observed.
16.4.5 Air vent discharge locations shall be as indicated on the plumbing plans.

16.5 Valve Access and Operation

16.5.1 Every valve shall be installed so that its operator can be reached and turned through its full travel without removing permanent construction.
16.5.2 Valves shall be installed with the stem at or above the horizontal.
NOTE A valve installed with its stem below the horizontal collects sediment in the bonnet and traps air in the body. (16.5.3)
16.5.4 Valves installed more than 8 ft above the finished floor shall be furnished with a chain operator or shall be located where a permanent platform or ladder gives access.

17 Water Hammer Arrestors

NOTE When a valve closes faster than the pressure wave can travel to the end of the pipe and back, the moving column of water stops against the closed valve and its momentum converts to a pressure spike that travels the system; solenoid valves, self-closing faucets, flush valves, and appliance fill valves all close that fast. (17.1)
NOTE The spike does not stay where it was generated — it reflects off closed ends and tees and fatigues joints, valve seats, and fixture connections throughout the connected piping. (17.2)
17.3 Water hammer arrestors shall be certified to ASSE 1010 and shall carry a size designation to PDI WH 201.
17.4 The water hammer arrestor type shall be as indicated in the datasheet.
Water Hammer Arrestor Typeselect
Sealed piston arrestor with a permanent gas charge
Sealed bellows arrestor with a permanent gas charge
Diaphragm arrestor with a permanent gas charge
17.5 An air chamber formed from a capped length of pipe shall not be used as a water hammer arrestor.
NOTE A capped pipe air chamber loses its air cushion as the air dissolves into the water, and once the chamber is water-filled it provides no attenuation and gives no outward sign that it has stopped working. (17.6)
17.7 The arrestor sizing method shall be as indicated in the datasheet.
Water Hammer Arrestor Sizing Methodselect
The fixture unit method in PDI WH 201
A surge analysis of the system
The fixture manufacturer's published arrestor selection for the specific fixture
17.8 The extent of arrestor coverage shall be as indicated in the datasheet.
Water Hammer Arrestor Coverageselect
At every quick-closing valve in the system
At every fixture group containing a quick-closing valve
At the locations the adopted plumbing code requires
At the locations a surge analysis identifies
17.9 Arrestors shall be installed within the maximum distance from the quick-closing valve that the arrestor manufacturer publishes.
17.10 Arrestors shall be installed in an orientation the arrestor manufacturer permits for the model furnished.
17.11 Arrestors concealed in construction shall be provided with an access panel sized to permit removal and replacement of the arrestor.

18 Hot Water Temperature Maintenance

18.1 Maintenance Method

NOTE Hot water that has cooled in the pipe has to be run to drain before usable water reaches the outlet, which wastes the water, wastes the energy already spent heating it, and leaves the branch sitting in the temperature band where building water organisms grow. (18.1.1)
18.1.2 The method by which hot water delivery temperature is maintained in the distribution piping shall be as indicated in the datasheet.
Hot Water Temperature Maintenance Methodselect
None because every run is within the permitted uncirculated volume
A circulated return loop
Electric heat trace on the supply piping
A circulated return loop on the mains with heat trace on the branches
Demand-initiated circulation using the cold water piping as the return path
Derived — the volume of water contained between the source of hot water and the farthest fixture outlet, compared against the maximum uncirculated volume Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code permits (by default)
NOTE The recirculation pump, its control, and the balancing devices at the equipment are specified in Water HeatersCommercial Water HeatersResolves to the current adopted revision.sync/water-heaters; the return piping, the branch balancing devices in that piping, and the heat trace are furnished under this standard. (18.1.3)
18.1.4 The maximum volume of water permitted between the circulated main or heat-traced main and the fixture outlet shall be as indicated in the datasheet.
Maximum Uncirculated Volume to a Fixture Outletrange
gal
0.10.250.50.7511.5234
Derived — the maximum volume Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code permits between the source of hot water and the fixture served (by default)
NOTE Energy codes state this limit as a water volume rather than a pipe length because the same length of larger pipe holds several times the water, and it is the volume that has to be purged before hot water arrives. (18.1.5)

18.2 Return Loop Piping

18.2.1 Requirements in this section apply where the datasheet selects a circulated return loop.
18.2.2 Where a circulated return loop is selected, the return piping shall be arranged so that every hot water main and riser served is included in a circulating path.
18.2.3 Where a circulated return loop is selected, a balancing device shall be provided in the return of each branch and each riser.
NOTE Without balancing, the return flow takes the path of least resistance through the shortest circuit, and the long circuits — which are the ones that most need the flow — receive almost none of it. (18.2.4)
18.2.5 The branch balancing device type shall be as indicated in the datasheet.
Hot Water Return Branch Balancing Deviceselect
A manual balancing valve with a memory stop and flow measurement ports
An automatic flow limiting valve with a fixed cartridge
A thermostatic balancing valve that modulates on return temperature
A pressure independent balancing valve
18.2.6 Balancing device locations shall be as indicated on the plumbing riser diagrams.
18.2.7 Where a circulated return loop is selected, the return piping shall be insulated to the same requirements as the hot water supply piping.
18.2.8 Where a circulated return loop is selected, the Contractor shall record the flow or the temperature each balancing device is set to and shall include the record in the closeout submittals.

18.3 Heat Trace

18.3.1 Requirements in this section apply where the datasheet selects electric heat trace.
18.3.2 Where heat trace is selected, the heat trace type shall be as indicated in the datasheet.
Temperature Maintenance Heat Trace Typeselect
Self-regulating parallel resistance cable
Zoned parallel resistance cable
Series resistance cable
Mineral insulated cable
18.3.3 Where heat trace is selected, it shall be listed for potable water pipe temperature maintenance and shall be installed, tested, and commissioned in accordance with IEEE 515.1 and NFPA 70.
18.3.4 Where heat trace is selected, it shall be applied to the pipe before the insulation is installed and shall be covered by the full specified insulation thickness.
18.3.5 Where heat trace is selected, each circuit shall be protected by a ground-fault equipment protection device.
18.3.6 Where heat trace is selected, the insulation jacket shall be permanently labeled to identify the presence of electric heat trace beneath it at intervals not exceeding 10 ft and at every access point.
18.3.7 Where heat trace is selected, insulation resistance shall be tested before the insulation is installed, after the insulation is installed, and again before acceptance, and each result shall be recorded.
NOTE Heat trace damaged during insulation work is invisible once the jacket is on, which is why the resistance test is repeated after insulating rather than only before. (18.3.8)

19 Hangers and Supports

19.1 Support Materials and Attachment

19.1.1 Piping shall be supported in accordance with ASME B31.9, MSS SP-58, MSS SP-69, and the adopted plumbing code.
19.1.2 The hanger and support material shall be as indicated in the datasheet.
Hanger and Support Materialselect
Carbon steel, hot-dip galvanized
Carbon steel, electroplated zinc
Carbon steel with a factory-applied epoxy or polymer coating
Type 304 stainless steel
Type 316 stainless steel
Copper plated carbon steel
19.1.3 Bare carbon steel or bare galvanized steel shall not bear directly against copper tube.
NOTE The galvanic cell that forms where a steel hanger touches wet copper tube consumes the zinc coating first and then the steel, and the assembly fails at the hanger rather than at the pipe. (19.1.4)
19.1.5 An isolating liner, an isolating insert, or a coated clamp shall be provided between the pipe and every hanger, support, guide, clamp, and sleeve where the hanger material and the pipe material differ.
19.1.6 Plastic and polymer piping shall be supported with hangers that provide a continuous bearing surface without sharp edges.
19.1.7 Hangers shall not restrain axial movement of the piping except at points designated as anchors.
19.1.8 Support attachments to the building structure shall be made only at points and by methods the structural drawings permit.
19.1.9 Support attachment methods shall be as indicated on the structural drawings and their attachment details.
19.1.10 Piping shall not be supported from another pipe, from ductwork, from conduit, from cable tray, from suspended ceiling framing, or from equipment.

19.2 Horizontal Support Spacing

19.2.1 The Contractor shall not exceed the following support spacings.
Piping Material Nominal Size Maximum Horizontal Spacing Maximum Vertical Spacing
Copper tube, drawn temper 1-1/4 in. and smaller 6 ft 10 ft
Copper tube, drawn temper 1-1/2 in. and larger 10 ft 10 ft
Copper tube, annealed temper All sizes Continuous support 10 ft
CPVC 1 in. and smaller 3 ft 10 ft
CPVC 1-1/4 in. and larger 4 ft 10 ft
PEX and PE-RT All sizes 32 in. 10 ft
PEX-AL-PEX All sizes 8 ft 10 ft
Polypropylene 1 in. and smaller 32 in. 10 ft
Polypropylene 1-1/4 in. and larger 4 ft 10 ft
Stainless steel pipe All sizes 12 ft 15 ft
Galvanized steel pipe All sizes 12 ft 15 ft
NOTE Thermoplastics creep under sustained load, so an unsupported span that looks acceptable at installation sags progressively over the years under the weight of the pipe and its water, which is why the plastic spacings are a fraction of the metal ones. (19.2.2)
19.2.3 Support spacing shall be reduced where the adopted plumbing code, the pipe manufacturer, or the operating temperature requires a shorter span than the table gives.
19.2.4 A support shall be provided within 12 in. of each change of direction and within 12 in. of each valve, arrestor, or in-line specialty.
19.2.5 A support shall be provided at each side of a flexible connector, an expansion joint, and a fixture connection assembly.

19.3 Vertical Support

19.3.1 The vertical support method shall be as indicated in the datasheet.
Vertical Riser Support Methodselect
A riser clamp at every floor carrying the weight at each level
A base support carrying the riser weight with guides at every floor above
A base support with a spring hanger at the top of the riser and guides between
Riser clamps at alternating floors with guides at the intervening floors
NOTE Riser support methods differ in where the weight lands and in how much axial movement is permitted: clamping at every floor divides the weight but also restrains expansion at every floor, while supporting at the base and guiding above lets the riser grow along its length. (19.3.2)
19.3.3 Risers shall be supported at the base and at every floor penetration or guide point the selected method requires.
19.3.4 Riser clamps bearing on the structure shall bear on a surface the structural drawings permit them to load.
19.3.5 Plastic and polymer risers shall be guided at each floor penetration so that axial movement is permitted and lateral deflection is not.

19.4 Seismic Restraint

NOTE A gravity hanger carries load in one direction only, so in a seismic event the pipe swings on its rods until it strikes something or until a joint takes the bending; a restraint adds the lateral and longitudinal capacity the hanger does not have. (19.4.1)
19.4.2 The scope of seismic restraint on the domestic water piping shall be as indicated in the datasheet.
Seismic Restraint Scopeselect
None because the piping falls below the threshold at which restraint is required
Piping above the code threshold size, restrained laterally and longitudinally
All distribution piping regardless of size, restrained laterally and longitudinally
All distribution piping, restrained laterally and longitudinally, with the additional bracing an essential facility requires
Derived — Seismic Design CategorySeismic Design CategoryParameterEach project supplies its own value.seismic-design-category, the component importance factor the project assigns to domestic water service, and the pipe size threshold IBC and ASCE 7 apply at that category (by default)
19.4.3 Where seismic restraint is required, it shall be designed and installed in accordance with IBC and ASCE 7.
19.4.4 Seismic restraint shall be designed by a registered design professional, or shall use a pre-approved detail listed for the loads, the pipe size, and the attachment condition in which it is installed.
19.4.5 Seismic restraint attachments to the structure shall be made only at points and by methods the structural drawings permit.
19.4.6 Seismic restraint shall not restrain the axial thermal movement the expansion provisions in this standard depend on.
19.4.7 Flexible connections shall be provided where piping crosses a building seismic joint, and shall accommodate the differential movement in every direction the structural drawings state.
19.4.8 Flexible connections shall be provided where piping enters a building through a foundation wall or a slab and where it connects to seismically isolated equipment.

20 Thermal Expansion

NOTE Piping grows when it is heated, and the growth is a property of the material and the temperature change rather than of the pressure or the flow, so a hot water run expands by the same amount whether it is full-flow or idle. (20.1)
NOTE Copper tube expands about 9.4 × 10⁻⁶ in./in./°F, austenitic stainless about 9.6 × 10⁻⁶, CPVC about 3.4 × 10⁻⁵, polypropylene about 8 × 10⁻⁵, and PEX about 9 × 10⁻⁵, so over a 100 ft run heated 70°F above its installed temperature the movement ranges from roughly 0.8 in. in copper to roughly 7-1/2 in. in PEX. (20.2)
20.3 The expansion compensation method shall be as indicated in the datasheet.
Thermal Expansion Compensation Methodselect
Direction changes inherent in the routing, with anchors and guides positioned to use them
Fabricated expansion loops
Fabricated expansion offsets
Axial bellows expansion joints
Slip type expansion joints
Flexible expansion compensators listed for the piping material
20.4 Expansion provision locations shall be as indicated on the plumbing riser diagrams and the expansion details.
20.5 Anchors shall be provided where the shop drawings show them and shall be constructed to transfer the anchor load into the structure at a point the structural drawings permit.
20.6 Guides shall be provided on each side of every expansion loop, offset, and joint, at the spacing the expansion joint manufacturer publishes.
20.7 A long straight run shall not be anchored at both ends without an expansion provision between the anchors.
20.8 Piping shall pass through sleeves, penetrations, and firestop assemblies with enough clearance for the calculated movement.
20.9 Piping shall not be restrained by insulation, by firestop material, or by contact with the structure at any point that is not a designated anchor.
NOTE An expansion provision that cannot move because the pipe is pinched at a penetration transfers the whole load to the nearest joint, and that joint is where the failure appears. (20.10)

21 Pipe Insulation

21.1 Insulation Materials and Ratings

NOTE Pipe insulation does two different jobs on the two services: on hot piping it keeps heat in the water, and on cold piping it keeps the pipe surface above the dew point of the air around it. (21.1.1)
NOTE Insulation on cold piping fails in a way hot insulation does not — once vapor reaches the cold surface it condenses inside the insulation, and the wet insulation both loses its thermal value and holds water against the pipe. (21.1.2)
21.1.3 Pipe insulation, its facing, its jacket, and its adhesives and sealants shall have a flame spread index not exceeding 25 and a smoke developed index not exceeding 50 when tested to ASTM E84.
21.1.4 Insulation used inside an air plenum shall be listed for plenum use.
21.1.5 The hot water pipe insulation material shall be as indicated in the datasheet.
Hot Water Pipe Insulation Materialselect
Mineral fiber to ASTM C547 with an all-service jacket
Closed cell elastomeric to ASTM C534
Rigid cellular polyisocyanurate to ASTM C591 with a jacket
Cellular glass to ASTM C552 with a jacket
Flexible aerogel blanket with a jacket
21.1.6 The cold water pipe insulation material shall be as indicated in the datasheet.
Cold Water Pipe Insulation Materialselect
Closed cell elastomeric to ASTM C534
Mineral fiber to ASTM C547 with a sealed vapor retarder jacket
Rigid cellular polyisocyanurate to ASTM C591 with a sealed vapor retarder jacket
Cellular glass to ASTM C552 with a sealed vapor retarder jacket
Flexible aerogel blanket with a sealed vapor retarder jacket
NOTE A closed cell material carries its vapor resistance in the insulation itself, so the vapor path is broken along the whole run; a fibrous material carries it in the jacket, so the vapor path is only as good as the last seam that was sealed. (21.1.7)
21.1.8 Where a jacket provides the vapor retarder, the jacket shall have a water vapor permeance not exceeding 0.02 perm when tested to ASTM C1136.
21.1.9 Insulation materials shall be rated for continuous service at the maximum operating temperature of the piping on which they are installed.

21.2 Insulation Thickness

21.2.1 The hot water and hot water return pipe insulation thickness shall be as indicated in the datasheet.
Hot Water Pipe Insulation Thicknessrange
in.
0.50.7511.522.534
Derived — the nominal pipe size, the fluid operating temperature, and the insulation conductivity, evaluated against the minimum thickness Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code requires for that combination (by default)
21.2.2 The cold water pipe insulation thickness shall be as indicated in the datasheet.
Cold Water Pipe Insulation Thicknessrange
in.
0.50.7511.522.53
Derived — the design dew point of the space, the pipe surface temperature that follows from Site Water Supply Temperature MinimumSite Water Supply Temperature MinimumParameterEach project supplies its own value.site-water-supply-temperature-minimum, and the minimum thickness Adopted Energy CodeAdopted Energy CodeParameterEach project supplies its own value.adopted-energy-code requires for the pipe size (by default)
21.2.3 Where the calculated condensation control thickness exceeds the energy code minimum, the calculated thickness shall govern.
21.2.4 Insulation thickness shall not be reduced to fit an obstruction, and where the space available will not accept the specified thickness the Contractor shall request a routing change from the Engineer of Record before installing the pipe.

21.3 Jacketing and Protection

21.3.1 The insulation jacket for piping in exposed interior locations shall be as indicated in the datasheet.
Insulation Jacket — Exposed Interior Locationsselect
The factory-applied all-service jacket alone
A polyvinyl chloride jacket
An aluminum jacket to ASTM C1729
A stainless steel jacket
A field-applied reinforced mastic coating
21.3.2 The insulation jacket for piping in exterior and wet locations shall be as indicated in the datasheet.
Insulation Jacket — Exterior and Wet Locationsselect
An aluminum jacket to ASTM C1729 with sealed laps
A stainless steel jacket with sealed laps
A polyvinyl chloride jacket with sealed laps
A field-applied reinforced mastic coating
21.3.3 Jacket laps on horizontal exterior piping shall be arranged to shed water.
21.3.4 Insulation on piping in locations subject to physical damage shall be protected by a metal jacket or by a mechanical guard.
21.3.5 The treatment of insulation at valves, flanges, and fittings shall be as indicated in the datasheet.
Insulation at Valves, Flanges, and Fittingsselect
Field-fabricated insulation finished to match the adjacent pipe insulation
Preformed fitting covers matching the pipe insulation material
Removable and reusable insulation jackets with mechanical fasteners
Removable jackets at valves and flanges with preformed covers at fittings
NOTE Bare valve bodies, flanges, and fittings are a small fraction of the surface area and a large fraction of the heat loss, and on cold piping they are where condensation appears first. (21.3.6)

21.4 Insulation Continuity

21.4.1 Insulation shall be continuous through sleeves, wall and floor penetrations, and hanger points.
21.4.2 An insulation protection shield or a rigid insert of sufficient compressive strength shall be provided at every hanger and support on insulated piping.
NOTE Without an insert, the hanger crushes the insulation at every support and the pipe bears on the hanger, which on cold piping puts a bare cold metal surface in the open air at every support point. (21.4.3)
21.4.4 On cold piping and on piping with a vapor retarder, the vapor retarder shall be continuous and unbroken at every seam, butt joint, end, fitting cover, valve jacket, hanger insert, and penetration.
21.4.5 Vapor retarder seams and joints shall be sealed with the vapor retarder manufacturer's adhesive, mastic, or matching tape.
21.4.6 Insulation shall be terminated and sealed at every point where it stops, so that no insulation end is left open.
21.4.7 Insulation shall not be installed until the pressure test on that section is complete and the section has been released.
21.4.8 Insulation that has become wet before or during installation shall be removed and replaced at the Contractor's cost.

22 Freeze Protection

NOTE Water expands as it freezes, and the pipe fails not where the ice forms but at the closed section between the ice plug and a closed valve or fixture, where the trapped water has nowhere to go. (22.1)
22.2 Piping shall not be routed through an exterior wall cavity outboard of the insulation, through an unheated attic, or through any other location subject to freezing, unless it is freeze-protected as specified in this standard.
22.3 The freeze protection method for piping in locations subject to freezing shall be as indicated in the datasheet.
Freeze Protection Methodselect
Rerouting the piping into conditioned space
Insulation alone, with the space maintained above freezing
Self-regulating freeze protection heat trace under the insulation
Series resistance freeze protection heat trace under the insulation
A drain-down arrangement with valves and drains for seasonal isolation
22.4 Where freeze protection heat trace is provided, it shall be listed for the pipe material on which it is installed and shall be installed, tested, and commissioned in accordance with IEEE 515.1 and NFPA 70.
22.5 Where freeze protection heat trace is provided, each circuit shall be protected by a ground-fault equipment protection device.
22.6 Where freeze protection heat trace is provided, the control method shall be as indicated in the datasheet.
Freeze Protection Heat Trace Controlselect
Self-regulating cable with no external control
An ambient sensing thermostat serving the circuit
A pipe sensing thermostat on each circuit
An electronic controller with alarm contacts to the building system
22.7 Where freeze protection heat trace is provided, loss of the heat trace circuit shall be annunciated at a location the Owner monitors.
NOTE A freeze protection circuit that has failed gives no indication until the pipe bursts, which is the reason the circuit is monitored rather than simply installed. (22.8)
22.9 Piping in a location subject to freezing shall be arranged so that it can be drained completely from an accessible drain valve.

23 Buried and Below-Slab Piping

23.1 Cover, Bedding, and Backfill

23.1.1 Buried piping shall be installed on a continuous bedding of sand or of screened granular material, free of rock, debris, and frozen material.
23.1.2 The bedding and cover thickness surrounding buried piping shall be as indicated in the datasheet.
Bedding and Surround Thickness Around Buried Pipingrange
in.
2346812
23.1.3 The minimum cover over buried water piping shall be as indicated in the datasheet.
Minimum Cover Over Buried Water Pipingrange
in.
612182430364248607296
Derived — Frost DepthFrost DepthParameterEach project supplies its own value.frost-depth and the minimum cover the adopted plumbing code requires over a water service (by default)
NOTE Piping under a heated slab is protected by the building above it, while piping that leaves the heated footprint is not, so the cover requirement changes at the point the pipe passes beyond the conditioned envelope. (23.1.4)
23.1.5 Backfill over buried piping shall be placed and compacted in lifts, and mechanical compaction equipment shall not be operated directly over the pipe until the specified cover is in place.
23.1.6 Where buried piping is installed below Seasonal High Groundwater ElevationSeasonal High Groundwater ElevationParameterEach project supplies its own value.seasonal-high-groundwater-elevation, the trench shall be dewatered until the backfill is placed, and empty piping shall be restrained against flotation.

23.2 Corrosion Protection and Sleeving

23.2.1 Metallic piping in soil shall be protected against external corrosion by the method the datasheet indicates.
External Corrosion Protection for Buried Metallic Pipingselect
Continuous polyethylene encasement to AWWA C105/A21.5
A factory-applied bonded coating
A field-applied tape wrap system
A continuous polyethylene sleeve with taped and lapped joints
A corrosion resistant material selected in place of a coating
23.2.2 Where an encasement, sleeve, or wrap is provided, it shall be continuous, shall extend not less than 12 in. beyond every fitting, and shall be lapped and sealed at every joint and at every termination.
23.2.3 The Engineer of Record shall evaluate the soil for resistivity, pH, chloride, sulfate, and the presence of corrosive fill before a buried metallic material is selected.
23.2.4 Piping shall be sleeved where it passes through a slab, a footing, or a foundation wall.
NOTE A pipe cast directly into concrete is restrained against thermal movement and abrades against the concrete, and it cannot be replaced without breaking the structure. (23.2.5)
23.2.6 The annular space at a sleeve through an exterior foundation wall or a below-grade slab shall be sealed watertight with a mechanical seal.

23.3 Below-Slab Joints and Testing

23.3.1 Joints in below-slab and buried piping shall be minimized, and where the piping material is available in a continuous length for the run it shall be installed without intermediate joints.
23.3.2 Below-slab and buried piping shall be pressure tested and inspected before it is covered, backfilled, or encased in concrete.
23.3.3 The below-slab and buried piping test shall be documented with dated photographs showing the gauge reading and every exposed joint, and the photographs shall be included in the pressure test report.
23.3.4 The documentation required before covering buried piping shall be as indicated in the datasheet.
Buried Piping Documentation Before Covercheckbox
☐ Dated photographs of the gauge reading
☐ Dated photographs of every exposed joint
☐ Written witness by the Authority Having Jurisdiction
☐ Written witness by the Engineer of Record
☐ A surveyed record of the as-built horizontal and vertical location
23.3.5 Buried piping covered before the required documentation is complete shall be uncovered at the Contractor's cost and reinstated at the Contractor's cost.

24 Installation

24.1 General Installation

24.1.1 Piping shall be installed in accordance with ASME B31.9, the adopted plumbing code, and the pipe manufacturer's published installation instructions for the material and joining method used.
24.1.2 Piping shall be installed parallel or perpendicular to the building lines except where a slope is required.
24.1.3 Piping shall be installed to permit the removal of every valve, specialty, and item of equipment without cutting pipe, using unions or flanges as required.
24.1.4 Piping shall be installed clear of the openings of electrical equipment, and shall not be routed directly above a switchboard, a panelboard, a motor control center, a transformer, or an open electrical enclosure.
24.1.5 Where the Contractor identifies a conflict that cannot be resolved by adjusting the routing within the allowances the drawings give, the Contractor shall request a routing change from the Engineer of Record before penetrating the structure.
24.1.6 The Contractor shall coordinate the routing with the structural, mechanical, electrical, and fire protection work before installation begins.

24.2 Cutting and Preparation

24.2.1 Pipe and tube shall be cut square with a tool the pipe manufacturer publishes for the material.
24.2.2 Burrs, chips, and sharp edges shall be removed from every cut end, inside and outside, before the joint is made.
NOTE An internal burr left in copper tube after wheel cutting creates a local acceleration in the flow at the fitting, and that is where erosion-corrosion starts on an otherwise correctly sized line. (24.2.3)
24.2.4 Cut ends shall be cleaned of cutting fluid, filings, and debris before the joint is made.
24.2.5 Steel wool and carbon steel brushes shall not be used to clean copper or stainless steel.

24.3 Copper Soldered Joints

24.3.1 Requirements in this section apply where copper joints are soldered.
24.3.2 Solder shall conform to ASTM B32 and shall be a lead-free alloy.
24.3.3 The solder alloy shall be as indicated in the datasheet.
Solder Alloyselect
Tin-silver
Tin-copper
Tin-antimony
Tin-copper-silver
Tin-silver-bismuth
24.3.4 Flux shall conform to ASTM B813 and shall be a water-flushable type.
NOTE Flux residue left inside the tube is mildly acidic and continues to attack the copper at the joint after the system is in service, and only a water-flushable flux can be removed by the flushing this standard requires. (24.3.5)
24.3.6 Flux shall be applied sparingly to the cleaned tube end and the cleaned fitting socket, and shall not be applied inside the fitting beyond the socket depth.
24.3.7 Joints shall be made in accordance with ASTM B828.
24.3.8 Heat shall be applied to the fitting rather than to the tube, and solder shall be applied at the joint edge when the assembly is hot enough to melt solder on contact.
24.3.9 A completed joint shall be allowed to cool without being quenched, moved, or loaded.
NOTE Overheating burns the flux and oxidizes the surfaces the solder must wet, which produces a joint that is filled at the mouth and void inside. (24.3.10)
24.3.11 External flux residue shall be wiped from the completed joint.

24.4 Copper Brazed Joints

24.4.1 Requirements in this section apply where copper joints are brazed.
24.4.2 The brazing filler metal shall conform to AWS A5.8/A5.8M.
24.4.3 The brazing filler metal shall be as indicated in the datasheet.
Brazing Filler Metalselect
A copper-phosphorus alloy
A copper-phosphorus-silver alloy
A silver alloy with flux
24.4.4 Copper-phosphorus filler metals are self-fluxing on copper-to-copper joints and shall not be used without flux on joints to copper alloy, bronze, or steel.
24.4.5 Copper-phosphorus filler metals shall not be used on ferrous base metals.
24.4.6 Joints shall be brazed in accordance with ASTM B828.
24.4.7 A hot work permit shall be obtained before brazing, and a fire watch shall be maintained for the period the permit requires.
24.4.8 Piping in which a brazed joint is being made shall be purged with an inert gas where the pipe manufacturer or the Engineer of Record requires it, to prevent internal oxide scale.

24.5 Solvent Cement Joints

24.5.1 Requirements in this section apply where CPVC joints are solvent cemented.
24.5.2 Solvent cement shall conform to ASTM F493 and shall be listed for CPVC.
24.5.3 Solvent cement listed for PVC shall not be used on CPVC.
24.5.4 The solvent cement system shall be as indicated in the datasheet.
CPVC Solvent Cement Systemselect
A primer followed by a separate solvent cement
A one-step solvent cement without a primer
A low volatile organic compound solvent cement system
24.5.5 Where the adopted plumbing code or the Authority Having Jurisdiction requires a primer, a primer shall be used regardless of the cement system selected.
24.5.6 Joints shall be made with the tube cut square, the end deburred and beveled, the joint dry fitted, and the insertion depth marked before cement is applied.
24.5.7 Cement shall be applied to the tube end and then to the fitting socket, and the joint shall be assembled immediately with a quarter turn and held until it resists push-out.
24.5.8 Cement surfaces shall be dry before cement is applied, and cement shall not be applied to a wet surface.
24.5.9 Excess cement shall be wiped from the outside of the completed joint.
24.5.10 A continuous bead of cement shall be visible around the full circumference of the completed joint.
24.5.11 Joints shall not be disturbed, moved, or loaded until the set time the cement manufacturer publishes for the ambient temperature has elapsed.
24.5.12 Joints shall not be pressurized until the cure time the cement manufacturer publishes for the ambient temperature, the pipe size, and the test pressure has elapsed.
NOTE Cure time lengthens sharply as ambient temperature falls, and a joint that would be ready in an hour at 75°F can need several hours at 40°F. (24.5.13)
24.5.14 Solvent cement shall not be applied at an ambient temperature outside the range the cement manufacturer publishes, unless the manufacturer publishes a procedure for that condition and the Contractor follows it.
24.5.15 The area in which solvent cementing is performed shall be ventilated as the cement manufacturer's safety data sheet requires.

24.6 Protection During Construction

24.6.1 Open ends of installed piping shall be capped or plugged at the end of each work period, from the first length installed through the completion of the pressure test.
NOTE An open pipe end left overnight collects dust, insects, standing water, and construction debris, and none of that is reliably removed by flushing once it is inside a distribution system. (24.6.2)
24.6.3 Installed piping shall be protected from damage by other trades, and temporary physical protection shall be provided where material handling, staging, or lift traffic passes an installed run.
24.6.4 Polymer piping installed before the building is closed in shall be shielded from ultraviolet exposure.
24.6.5 Piping damaged during construction shall be cut out and replaced rather than repaired, unless the pipe manufacturer publishes a repair for the specific damage.
24.6.6 The Contractor shall not use the domestic water piping as a grounding electrode, a support, a lever, or a lifting point.

25 Piping Identification

25.1 Piping shall be identified in accordance with ASME A13.1.
25.2 Identification shall give the contents of the pipe and the direction of flow.
25.3 The pipe marker type shall be as indicated in the datasheet.
Pipe Marker Typeselect
Preprinted self-adhesive markers
Preprinted snap-on markers
Preprinted markers secured with color-coded bands
Stenciled markings applied to the jacket
25.4 Markers shall be applied at every point where the piping enters or leaves a wall, floor, ceiling, or enclosure, at every valve, at every branch take-off, at every change of direction, at every access point, and at intervals not exceeding the datasheet value along straight runs.
Maximum Pipe Marker Spacing on Straight Runsrange
ft
10152025304050
25.5 Markers shall be applied over the finished insulation or jacket rather than on the pipe beneath it.
25.6 Every valve except a fixture stop shall be tagged with a permanently marked tag bearing the valve number in the valve schedule.
25.7 The valve tag material shall be as indicated in the datasheet.
Valve Tag Materialselect
Stamped brass
Stamped stainless steel
Stamped anodized aluminum
Engraved laminated plastic
25.8 Valve tags shall be attached with a corrosion resistant chain, cable, or S-hook.
25.9 A valve chart listing every tagged valve by number, service, and location shall be framed under glass or rigid laminate and mounted where the Owner directs.
25.10 Buried piping shall be marked with a continuous detectable marking tape placed in the backfill above the pipe.
25.11 Buried non-metallic piping shall be provided with a continuous tracer wire terminating in an accessible location at each end.

26 Pressure Testing

26.1 Test Requirements

26.1.1 Piping shall be pressure tested after the joints in the test section are complete and cured, and before the section is insulated, concealed, backfilled, or covered.
26.1.2 The test medium shall be as indicated in the datasheet.
Pressure Test Mediumselect
Water
Air
Water on plastic piping and air on metallic piping
Water with air used only for a preliminary tightness check at reduced pressure
NOTE Air is compressible and stores far more energy at a given pressure than water does, so a joint that separates during an air test releases that energy rather than simply weeping; several plastic pipe manufacturers prohibit air testing of their products for that reason. (26.1.3)
26.1.4 Air shall not be used as the test medium on any piping whose manufacturer prohibits it.
26.1.5 Where air is used as the test medium, the test area shall be cleared of personnel who are not conducting the test, and the pressurizing source shall be fitted with a relief device set no higher than the test pressure.
26.1.6 The test pressure shall be as indicated in the datasheet.
Test Pressurerange
psi
5080100125150175200250300
Derived — 1.5 times the system working pressure, limited by the lowest pressure rating among the pipe, fittings, valves, and specialties in the test section, and not less than the minimum the adopted plumbing code requires (by default)
26.1.7 The test duration shall be as indicated in the datasheet.
Test Durationrange
hours
0.250.512481224
26.1.8 The test pressure shall not exceed the pressure rating of the lowest-rated component in the test section.
26.1.9 Components whose rating is below the test pressure shall be isolated from the test section or removed and replaced with a spool for the duration of the test.
26.1.10 Piping shall be tested in sections small enough that a failure can be located, and the extent of each test section shall be recorded in the test report.

26.2 Test Procedure

26.2.1 The system shall be filled slowly from the lowest point with every high point vent and every outlet stop open, and shall be vented until water flows free of air from each vent.
NOTE Air trapped in a hydrostatic test compresses under pressure and then dissolves into the water, and the resulting pressure decay looks exactly like a slow leak on the gauge. (26.2.2)
26.2.3 The section shall be allowed to stabilize at test pressure for not less than 15 minutes before the test period begins.
26.2.4 The gauge pressure shall be recorded at the start of the test period, at intervals not exceeding 30 minutes during the test period, and at the end of the test period.
26.2.5 Test gauges shall have a full scale range not less than 1.5 times and not more than 4 times the test pressure, shall have a dial not less than 4 in. in diameter or an equivalent digital resolution, and shall have been calibrated within the 12 months preceding the test.
26.2.6 The gauge identification number and the calibration date shall be recorded in the test report.
26.2.7 The test is satisfactory when the gauge pressure holds without decay for the full test period and no leakage is visible at any joint, fitting, valve, or connection in the section.
26.2.8 Where the Contractor and the Engineer of Record disagree whether an observed pressure change constitutes a failure, the Engineer of Record shall make the initial determination.
26.2.9 A failed joint shall be cut out and remade rather than caulked, peened, or re-soldered in place.
26.2.10 The section shall be retested in full after any repair.
26.2.11 The cost of retesting after a failed test, including the cost of removing and reinstating any construction that conceals the section, shall be borne by the Contractor.

27 Flushing and Disinfection

27.1 Flushing

27.1.1 The system shall be flushed with potable water before it is disinfected.
27.1.2 Flushing shall be carried out progressively from the point of supply outward, through each riser, each branch, and each outlet in turn.
27.1.3 Flushing shall continue at each outlet until the discharge is free of visible particulate and discoloration and matches the appearance of the incoming supply.
27.1.4 Where the Contractor and the Engineer of Record disagree whether an outlet has run clear, the Engineer of Record shall make the initial determination.
27.1.5 Strainers, aerators, and flow restrictors shall be removed before flushing and shall be cleaned and reinstalled after the final flush.
27.1.6 The flush shall be recorded by riser, branch, and outlet, and the record shall be included in the disinfection report.
27.1.7 Disinfection shall not begin until the flushing record is complete.

27.2 Disinfection

NOTE Disinfection is what removes the organisms introduced during construction — from handling, from cut ends, from standing water in a stored coil, and from debris that entered an open pipe end — and the adopted plumbing code requires it before the system is placed in service. (27.2.1)
27.2.2 The system shall be disinfected after the pressure test and after flushing, and before it is placed in service.
27.2.3 The disinfection procedure shall be coordinated with the water purveyor, and any additional requirement the purveyor imposes shall be met.
27.2.4 The disinfection method shall be as indicated in the datasheet.
Disinfection Methodselect
Sodium hypochlorite solution
Calcium hypochlorite granules or tablets
Chlorine dioxide
Hydrogen peroxide with silver stabilizer
Thermal disinfection by circulating water above the pasteurization temperature
27.2.5 Disinfectants shall be of a grade certified for potable water use.
27.2.6 Thermal disinfection shall not be used on piping whose material is not rated for continuous service at the disinfection temperature.
27.2.7 The initial disinfectant concentration shall be as indicated in the datasheet.
Initial Disinfectant Concentrationrange
mg/L
510255075100150200
27.2.8 The contact time shall be as indicated in the datasheet.
Disinfectant Contact Timerange
hours
0.5136122448
27.2.9 The minimum residual disinfectant concentration at the end of the contact period shall be as indicated in the datasheet.
Minimum Residual at the End of the Contact Periodrange
mg/L
15102550100
27.2.10 The procedure shall follow AWWA C651 as adapted for building distribution piping, together with any additional requirement of the adopted plumbing code.
27.2.11 Every valve, stop, faucet, and specialty in the system shall be operated through its full travel during the contact period so that every wetted surface is exposed to the disinfectant.
NOTE A valve left closed during disinfection shields everything behind it, and that branch is the one that later returns a positive sample. (27.2.12)
27.2.13 The residual shall be measured at the point of supply, at the end of each riser, at each zone extremity, and at the outlets most remote from the fill point, and each reading shall be recorded against its location.
27.2.14 Where the residual at any sample point falls below the specified minimum, the system shall be redosed to the initial concentration and the contact period shall be repeated in full.
27.2.15 After a satisfactory contact period the system shall be flushed until the disinfectant concentration at every outlet is no greater than that of the incoming supply.
27.2.16 Disinfectant-bearing flush water shall be neutralized or dechlorinated before discharge where the water purveyor, the sewer authority, or the discharge permit requires it.

27.3 Bacteriological Testing

27.3.1 Samples shall be collected after the final flush from outlets distributed across the system, including the outlet most remote from the point of supply on each riser and in each zone.
27.3.2 The number of samples shall be not less than one per floor, or one per isolated zone where the system is zoned, and not less than three for any system.
27.3.3 The bacteriological analysis scope shall be as indicated in the datasheet.
Bacteriological Analysis Scopeselect
Total coliform
Total coliform with heterotrophic plate count
Total coliform with heterotrophic plate count and Legionella culture
27.3.4 Samples shall be collected in sterile containers, held within the temperature and holding time the laboratory specifies, and analyzed by a laboratory accredited or certified by the state for drinking water analysis.
27.3.5 The system shall not be placed in service until every sample returns an absence of total coliform.
27.3.6 Where a sample returns a positive result, the Contractor shall identify the probable cause before redisinfecting, and shall report the cause and the corrective action to the Engineer of Record.
27.3.7 Where a sample returns a positive result, the system shall be redisinfected and resampled in full.
27.3.8 The cost of redisinfection and resampling after a positive result shall be borne by the Contractor, except where the Engineer of Record determines that the contamination originated in the incoming supply.
27.3.9 The system shall not be placed in service with an outstanding positive bacteriological result.

28 Delivery, Storage, and Handling

28.1 Pipe, tube, fittings, valves, and specialties shall be delivered in the manufacturer's packaging with the markings and the potable-contact certification marks legible and intact.
28.2 Deliveries shall be inspected on receipt, and material that arrives unmarked, damaged, open-ended, or of a grade other than that specified shall be rejected and returned.
28.3 Material of a lighter wall series, a lower grade, or a lower pressure rating than specified shall not be accepted, and packaging similarity shall not be treated as evidence of equivalence.
28.4 Pipe and tube shall be stored under cover, off the ground on continuous dunnage, and supported at intervals that prevent permanent sag.
28.5 Pipe and tube shall be stored with end caps or plugs in place.
28.6 Polymer pipe and tube shall be stored out of direct sunlight and away from artificial ultraviolet sources.
28.7 Coiled tubing shall be stored at or above the coil diameter the manufacturer publishes.
28.8 Valves shall be stored with their operators in the position the valve manufacturer specifies for storage, and with their end protectors in place.
28.9 Gaskets, sealing elements, solvent cements, primers, and fluxes shall be stored within the temperature range the manufacturer publishes, and shall not be used after the expiration date printed on the container.
28.10 Solvent cement that has thickened, gelled, or separated shall be discarded and shall not be thinned for use.
28.11 Material shall be handled without dropping, dragging, or bending, and shall not be used as a lever, a support, or a lifting point.
28.12 Kinked, dented, gouged, flattened, or scored material shall be cut out and discarded.

29 Warranty

29.1 The Contractor shall warrant the domestic water piping installation against defects in materials and workmanship for the period indicated in the datasheet, beginning at the date of substantial completion.
Installation Warranty Periodrange
years
123510
29.2 The warranty shall cover joint failure, fitting failure, pipe failure, valve seat and stem seal leakage attributable to a manufacturing or workmanship defect, water hammer arrestor failure, insulation and vapor retarder failure, and heat trace failure.
29.3 The warranty shall cover the repair of the failed component, the restoration of any construction opened to reach it, and the repair of building finishes and Owner property damaged by the failure or by the water it released.
29.4 The warranty shall not cover damage from freezing where the building heating system was not maintained in operation, damage from water chemistry outside the pipe manufacturer's published limits where the Contractor reported the exceedance before ordering the material, damage from operation outside the specified pressure and temperature range, or physical damage caused by others after the work was accepted.
29.5 Where a warranty repair is made, the repaired work shall carry a new warranty for the full original period from the date the repair is accepted, or for the remainder of the original period, whichever ends later.
29.6 The Contractor shall respond to a reported warranty failure that is actively releasing water within 24 hours of the report.
29.7 The Contractor shall respond to a reported warranty failure that is not actively releasing water within 5 business days of the report.
29.8 Manufacturer warranties for the products furnished shall be assigned to the Owner at substantial completion and included in the closeout submittal package.
29.9 Where a manufacturer conditions its warranty on registration, the Contractor shall complete the registration in the Owner's name before substantial completion.

30 Spare Parts

30.1 The Contractor shall deliver the spare parts indicated in the datasheet to the Owner before substantial completion.
Spare Parts to Be Deliveredcheckbox
☐ One repair kit for each type and size of valve installed
☐ One spare valve of each type and size installed at a critical isolation point
☐ One spare water hammer arrestor of each size installed
☐ Operating keys for every loose-key valve, with two spares
☐ One spare handle or handwheel for each valve type installed
☐ Sufficient pipe, fittings, and joining materials to make one repair in each pipe material and size installed
☐ One spare heat trace termination and splice kit for each circuit type installed
☐ One spare removable insulation jacket for each valve size fitted with one
30.2 Spare parts shall be the same product, from the same manufacturer, as the item installed.
30.3 Spare parts shall be delivered in labeled packaging identifying the part, the equipment it serves, and the quantity, and shall be stored where the Owner directs.
30.4 The Contractor shall obtain a signed receipt from the Owner for the spare parts delivered and shall include the receipt in the closeout submittals.