Uses of Plastic Pipe
Pressure applications :
Plastic pressure piping is used for many industrial processes, in heating and cooling systems, fire protection installations, gas distribution, and for water supply and distribution.
Potable water applications include cold water services from wells or water mains up to the building as well as hot and cold water distribution piping within buildings.
ABS, PE and PVC materials are all available with 73 F stress rating for use in pressure piping. PE piping is used extensively for cold water service lines and water distribution systems outside the building. Its low temperature flexibility make it especially suited for use in applications where temperature of 35 F and lower will occur.
The maximum temperature at which PE has an HDS rating is 140 F.
MATERIALS WITH HDS RATINGS FOR HIGHER TEMPERATURES
Chlorinated Poly (Vinyl Chloride) (CPVC), and cross-linked polyethylene (PEX) materials are available that are rated for long term service at 180 F as well as for cold water applications. Hot and cold water distribution system piping made from these materials has a working pressure rating of 100 psi at 180 F. These systems are tested at 150 psi at 210 F for at least 48 hours to assure integrity at those condition, which may develop in the event the water heater controls malfunction. Thus, such materials are suitable for hot water distribution where water heaters are installed with relief valves set at 150 psi, 210 F.
All plumbing codes require the use of piping having the 100 psi @ 180 F rating for both the hot and the cold water portions of the water distribution system.