Table 1.
Types of building plumbing components
| Components | Description |
|---|---|
| Water source | Municipal water, onsite well, treated surface water, rainwater. |
| Service line | Pipe system that carries water from the source to the building water system. Service line materials are variable and may or may not be the same as indoor pipes. |
| Safety devices including valves | Pressure relief valve, pressure reduction value, isolation valve, mixing valve, thermostatic mixing valves, backflow prevention device, water hammer arrestors. Materials can include aluminum, brass, copper, lead, plastic, and stainless steel. |
| Water treatment devices | Filter, strainer, water softener, chemical addition equipment for disinfection and corrosion control. |
| Water service and distribution piping and faucet connectors | Various material types have been used, including acrylonitrile butadiene styrene (ABS), brass, cast iron (CI), chlorinated polyvinyl chloride (CPVC), copper, crosslinked polyethylene (PEX), ductile iron (DI), high density polyethylene (HDPE), lead, lead lined steel, multilayer pipes, polyethylene raised temperature (PERT), polypropylene (PP), unplasticized polyvinyl chloride (uPVC), polyvinylidene fluoride (PVDF), black steel, stainless steel. |
| Hot water recirculation system | Hot water is pumped through primary and secondary water heater loops, which serve different building zones to reduce the delivery time of hot water. These have to be hydraulically balanced. Equipment includes master mixing valves, local mixing valves, flow‐balancing valves, pressure‐reducing valves, hot water return pumps, and water heaters. Multiple temperature loops may exist. Operation of pumps may be intermittent in some systems. |
| Fixtures and fixture fittings | Aerator, air washers, atomizers, bathtub, bidet, decorative fountains, dishwasher, drinking fountain, eyewash stations, manual faucet, electronic faucet, faucet flow restrictors, hoses, point‐of‐use mixing valves, hot tubs, humidifiers, ice machines, misters, shower head, shower wand, sink, tub spout, toilet, urinal, washbasin |
| Pumps | Pumps are often used for pressure boosting within the building (i.e., for multistory buildings) where water pressure entering the building is not adequate for water use at distal locations. Pumps are also used for hot water recirculation systems. |
| Tanks | Standard water heater, pressure tanks, on‐demand water heater, hydropneumatic tanks, cold water supply storage tank. Water heaters can contain Mg or Al sacrificial anodes and plastic dip tubes. |
| Point‐of‐use devices | On‐faucet treatment system, under sink treatment system. |
Note: ASHRAE 188 defines the delivery system for hot and cold water as the “potable” water system (ASHRAE Standards Committee, 2018), and it is sometimes referred to as “domestic” water. Some of the components contain both metal and plastic subparts. These include gaskets; polysulfone or PEX dip tubes; and liners and coatings such as glass, ceramic, epoxy, polyurethane, polyurea, and fiberglass. Gaskets may be ethylene propylene diene monomer (EPDM) (sulfur or peroxide crosslinked), butyl rubber (BR), natural rubber (NBR), neoprene, styrene butadiene rubber (SBR), and synthetic rubber.