Water and other fluid circuits are pressure tested for safety and leakage, using water at a pressure of 1.5 times the working pressure, or as required.
The opportunity is taken, while filling for testing, to ensure that the circuits can be filled without airlocks. Air vents at high points of the circuit may be automatic or manual. While the pipes are full, pumps should be run if possible to dislodge any dirt before draining down and cleaning the strainers. If a lot of dirt is found, the pipework should be filled again and reflushed. In any case, the pumps should be run at the earliest opportunity and the strainers cleaned out.
Fluids, if other than water, are not put in until this pressure testing and flushing has been carried out.
Posted in Refrigeration and Air Conditioning