This guidance note has been issued by the Institute of Refridgeration (IoR). It highlights three different ways in which a system has to be tested under pressure:
Strength Pressure Testing is the application of a pressure well above the design pressure of the component or system. It is intended as a proof test to demonstrate that the pressure equipment is capable of operating over long periods at pressures approaching the design pressure.
Tightness Testing is the process of checking a component or system during manufacturing or construction to certify that it is capable of operating in a leak‐free manner. It is done before any refrigerant is put into the system to ensure that the refrigerant will not leak out when the plant is charged.
Leak Testing is the process of inspecting an operational system to ensure that there is no leakage of refrigerant from it.
The guidance note is intended for designers of components and systems, managers of staff who are required to perform the tests and clients who engage contractors to do these tests on their equipment. It stresses the importance of all parties using the same terms to describe the tests in order to ensure that there is no confusion or ambiguity. Each of the tests is required by law, either before the system is put into service or at regular intervals throughout its operational life.
The guidance note is available in full here.
Institute of Refrigeration July 2021