Domestic Water Piping
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 5
to Rev 6
in Domestic Water Piping.
---
title: Domestic Water Piping
…190 unchanged lines
### Type M has the thinnest wall and is acceptable in low-pressure applications where permitted by the local plumbing code, but is generally not recommended for commercial service. {note}
+### The copper tube service and wall type shall be specified for each domestic water piping application, and Type M shall be used only where permitted by the local plumbing code.
+
```datasheet
label: Copper Tube — Service and Wall Type
…46 unchanged lines
#### Type K copper, conforming to ASTM B88, is the standard for underground and below-slab domestic water piping due to its heavier wall thickness, which provides additional resistance to external corrosion, soil loading, and incidental damage. {note}
+#### The pipe material for underground and below-slab domestic water piping shall be specified for each installation.
+
```datasheet
label: Underground / Below-Slab Pipe Material
…20 unchanged lines
### CPVC does not corrode in aggressive water chemistries that attack copper, does not support pinhole leak failures, and has a pressure rating of 100 psi at 180°F for ASTM D2846 CTS material, making it suitable for domestic hot water service temperatures. {note}
+### The CPVC pipe standard and dimension system shall be specified for each CPVC domestic water piping application.
+
```datasheet
label: CPVC Pipe Standard
…21 unchanged lines
### PEX is available in three crosslinking methods — peroxide (PEX-a), silane (PEX-b), and electron beam (PEX-c) — all of which meet ASTM F876 but which differ in flexibility, expansion memory, and fitting compatibility. {note}
+### The PEX crosslinking method shall be specified, since the fitting system and tools are not interchangeable between the three available methods.
+
```datasheet
label: PEX Tubing — Crosslinking Method
…25 unchanged lines
### Stainless steel is common in food service, pharmaceutical, semiconductor, and certain healthcare applications where water purity and cleanability are paramount. {note}
+### Where stainless steel pipe is used, the grade shall be specified based on the required water purity and cleanability of the application.
+
```datasheet
label: Stainless Steel Grade (Where Used)
…69 unchanged lines
### Wrought fittings are preferred over cast bronze fittings because they are available in the full range of sizes, have tighter dimensional tolerances, and provide a slightly stronger joint due to their homogeneous material at the joint interface. {note}
+### The copper fitting standard and joining method shall be specified for each copper domestic water piping application.
+
```datasheet
label: Copper Fitting Standard
…38 unchanged lines
### The crimp or clamp is applied with a calibrated, go/no-go tool that provides a defined, verified joint geometry. {note}
+### PEX fittings shall be selected to match the tubing's crosslinking method and shall be used with the manufacturer's specified tools only.
+
+### The Contractor shall not mix fitting systems; use of a crimp tool to install an expansion-type fitting, or the use of one manufacturer's expansion ring on another manufacturer's fitting, shall not be permitted and shall be cause for rejection of the joint.
+
+### Cold expansion is the preferred fitting method for commercial PEX installations in 1/2 in. through 2 in. sizes.
+
```datasheet
label: PEX Fitting Method
…6 unchanged lines
```
−### PEX fittings shall be selected to match the tubing's crosslinking method and shall be used with the manufacturer's specified tools only.
−
−### The Contractor shall not mix fitting systems; use of a crimp tool to install an expansion-type fitting, or the use of one manufacturer's expansion ring on another manufacturer's fitting, shall not be permitted and shall be cause for rejection of the joint.
−
−### Cold expansion is the preferred fitting method for commercial PEX installations in 1/2 in. through 2 in. sizes.
−
# Joining Methods {toc}
## Copper — Soldering {toc}
−### Soldering is the standard joining method for copper tube and fittings 2 in. and smaller. {note}
+### Soldering is the standard joining method for copper tube and fittings 2 in. and smaller.
```datasheet
…129 unchanged lines
### Butterfly valves are preferred for 2-1/2 in. and larger isolation service due to their lower cost, lighter weight, and easier manual operation compared to large ball or gate valves. {note}
+### The isolation valve type shall be specified for each isolation valve location 2 in. and smaller.
+
```datasheet
label: Isolation Valve Type — 2 in. and Smaller
…6 unchanged lines
```
+### The isolation valve type shall be specified for each isolation valve location 2-1/2 in. and larger.
+
```datasheet
label: Isolation Valve Type — 2-1/2 in. and Larger
…27 unchanged lines
### They are the preferred type for pump discharge applications and for any location where water hammer from abrupt check valve closure is a concern. {note}
+### Check valves shall be provided at all pump discharges, at all locations where backflow through the check valve could cause contamination or system damage, and at all other locations indicated on the drawings.
+
+### Swing check valves are acceptable in non-critical, gravity-drain, or low-velocity applications where water hammer is not a concern.
+
```datasheet
label: Check Valve Type
…6 unchanged lines
```
−### Check valves shall be provided at all pump discharges, at all locations where backflow through the check valve could cause contamination or system damage, and at all other locations indicated on the drawings.
−
−### Swing check valves are acceptable in non-critical, gravity-drain, or low-velocity applications where water hammer is not a concern.
−
## Drain Valves {toc}
…15 unchanged lines
### PRV selection and sizing is the responsibility of the Engineer; this standard covers the installation requirements for the PRV piping assembly. {note}
+### Where building water pressure exceeds 80 psi at the service entrance, a pressure reducing valve (PRV) shall be installed to limit system pressure to a level safe for the piping and fixtures served.
+
```datasheet
label: Pressure Reducing Valve Required
…6 unchanged lines
```
−### Where building water pressure exceeds 80 psi at the service entrance, a pressure reducing valve (PRV) shall be installed to limit system pressure to a level safe for the piping and fixtures served.
−
### The PRV piping assembly shall include isolation valves on the inlet and outlet, a strainer on the inlet, a pressure gauge on the outlet, and a union or flanged connection for PRV removal and replacement.
…8 unchanged lines
### Water hammer arrestors absorb the pressure spike using a precharged gas chamber separated from the waterway by a piston; when the surge arrives, the piston compresses the gas cushion and dissipates the energy before it propagates. {note}
−```datasheet
−label: Water Hammer Arrestors — Installation Requirement
−type: radio
−options:
− - "Required at all quick-closing valves and solenoid valves (comprehensive)"
− - "Required at fixture groups per plumbing code minimum (IPC or UPC)"
− - "Not required — system analysis confirms acceptable surge levels"
−default: "Required at fixture groups per plumbing code minimum (IPC or UPC)"
−```
+### Water hammer arrestors shall conform to ASSE 1010 and shall be sized using the Plumbing and Drainage Institute (PDI) fixture unit method, which assigns water supply fixture units (WSFU) to each fixture type and then determines the required arrestor capacity rating (PDI sizes A through F).
```datasheet
…6 unchanged lines
```
−### Water hammer arrestors shall conform to ASSE 1010 and shall be sized using the Plumbing and Drainage Institute (PDI) fixture unit method, which assigns water supply fixture units (WSFU) to each fixture type and then determines the required arrestor capacity rating (PDI sizes A through F).
−
### Arrestors shall be installed as close as practical to the quick-closing valve that generates the surge, and in the orientation — vertical, horizontal, or multi-position — permitted by the manufacturer.
+```datasheet
+label: Water Hammer Arrestors — Installation Requirement
+type: radio
+options:
+ - "Required at all quick-closing valves and solenoid valves (comprehensive)"
+ - "Required at fixture groups per plumbing code minimum (IPC or UPC)"
+ - "Not required — system analysis confirms acceptable surge levels"
+default: "Required at fixture groups per plumbing code minimum (IPC or UPC)"
+```
+
### Arrestors shall be located in an accessible position — behind an access panel if concealed in a wall — to permit inspection and replacement without demolition.
…15 unchanged lines
#### The operational conflict between energy codes (which encourage lower water heater temperatures) and Legionella prevention (which requires higher temperatures) is addressed through thermostatic mixing valves at point-of-use: the water heater stores and circulates water at 120°F to 140°F for Legionella control, and a certified thermostatic mixing valve conforming to ASSE 1017 blends down to a safe delivery temperature at the fixture. {note}
+#### Hot water storage shall be maintained at a minimum of 120°F, and the recirculation return temperature shall be maintained at a minimum of 110°F, to inhibit Legionella multiplication throughout the distribution system.
+
```datasheet
label: Hot Water Storage Temperature (Legionella Control)
…18 unchanged lines
```
−#### Hot water storage shall be maintained at a minimum of 120°F, and the recirculation return temperature shall be maintained at a minimum of 110°F, to inhibit Legionella multiplication throughout the distribution system.
−
#### Healthcare facilities shall comply with NFPA 99 and the applicable state health department requirements, which typically require higher storage and distribution temperatures and a formal water management program.
…32 unchanged lines
#### Without balancing, the shortest-path branches circulate at excess flow while the longest branches stagnate, defeating Legionella control in the dead legs. {note}
+#### Where the recirculation loop serves multiple branches or multiple risers, balancing valves or pressure-independent automatic balancing valves shall be provided at each branch take-off or riser base on the return circuit to ensure that flow is proportional to the heat loss of each branch rather than taking the path of least resistance.
+
```datasheet
label: Recirculation Balancing Valve Type
…6 unchanged lines
```
−#### Where the recirculation loop serves multiple branches or multiple risers, balancing valves or pressure-independent automatic balancing valves shall be provided at each branch take-off or riser base on the return circuit to ensure that flow is proportional to the heat loss of each branch rather than taking the path of least resistance.
−
#### Balancing valve locations shall be [[drawing: as indicated on the plumbing riser diagrams]].
…90 unchanged lines
### In SDC C and above, domestic water piping 2-1/2 in. and larger generally requires lateral and longitudinal seismic restraint. {note}
+### Where required by the applicable building code (IBC and ASCE 7), piping shall be braced for seismic loads.
+
```datasheet
label: Seismic Bracing
…6 unchanged lines
```
−### Where required by the applicable building code (IBC and ASCE 7), piping shall be braced for seismic loads.
−
### The Contractor shall confirm the project's SDC and the applicable threshold pipe size with the Engineer before beginning installation.
# Pipe Insulation {toc}
−## Purpose and Code Basis {toc}
+## Insulation Functions and Code Basis {toc}
### Pipe insulation on domestic water piping serves three distinct functions depending on the service: on hot water supply and recirculation piping, insulation reduces heat loss to the surrounding space, maintains acceptable delivery temperature at fixtures, reduces the energy consumed by the water heating system, and is required by ASHRAE 90.1 and the applicable energy code. {note}
…42 unchanged lines
### Fiberglass insulation with ASJ jacket is acceptable but requires that every seam, longitudinal cut, end cap, fitting insulation, and valve cover be properly sealed; any unsealed gap allows water vapor to migrate to the cold pipe surface, condense, saturate the insulation, and eventually drip. {note}
+### The cold water pipe insulation material shall be specified, and vapor retarder integrity shall be maintained where a fiberglass ASJ jacket system is selected.
+
```datasheet
label: Cold Water Pipe Insulation Material
…5 unchanged lines
```
+### The cold water pipe insulation thickness shall be specified based on pipe size, ambient humidity, and the governing energy code.
+
```datasheet
label: Cold Water Pipe Insulation Thickness
…98 unchanged lines
# Disinfection {toc}
−## Purpose and Code Basis {toc}
+## Disinfection Requirement and Code Basis {toc}
### Disinfection destroys bacteria introduced during construction from handling, pipe cutting, soldering flux residue, standing water, and construction debris. {note}
…249 unchanged lines
## Where manufacturer warranty documentation requires Owner registration, the Contractor shall initiate registration before substantial completion.