Chemical resistance needs to be checked, as well,to insure that there will not be a problem. Part of your application analysis should include the potential for shock pressure generation, i.e., water hammer in the system that could damage the plastic valve or strainer. Things to look for include a system flow rate of greater than 8 feet per second, quick starting pumps, positive displacement pumps, fast opening or closing actuated valves, and solenoid valves. Once it's determined that ALL of the application parameters are OK for the plastic component, it is impotrant to look at how the plastic component is installed. Stress on the plastic valve or strainer is the single most important installation factor to consider.
Stress can cause immediate damage or it can build up over time and cause damage later on.
One is improper alignment of the plastic component in the metal piping system. If either one has to be forced into position, it s sure to cause problems. Thermal expansion can be a problem is some applications. Expansion joints can help compensate for this. Another solution is to install plastic pipe on the inlet and outlet of the valve or strainer to isolate it from the metal pipe.