Pressure testing has implications on all of the individual system components, i.e. pipes, fittings, valves, coil etc., therefore the pressure rating of all the components needs to be considered when deciding on a suitable test pressure.
There are two pressure tests relating to valves:
System Pressure Test – to test integrity of the finished assembled system, i.e. ability of the completed assembly of individual components to withstand pressure.
Valve shut-off Pressure Test – to test the ability of a valve, typically an Isolation Valve, to close against a pressure.
Manufacture’s valves to allow system pressure testing to be carried out at 1.5 times maximum working pressure of the valve, i.e. for PN16 valves the test pressure can be 16 x 1.5 = 24 bar.
Note that all valves must be in an open position
The shut-off pressure test can be carried out at 1.1 time maximum working pressure, i.e. for a PN16 valve the test pressure can be 16 x 1.1 = 17.6 bar.
Ref - cranefs