Hydrotest vent and drain

Dear members;

Is it true that vent and drain are needed at every high and low point of piping if water is used for hydrotest? what if air or steam are used?

Can someone explain the general procure about how to use them in the hydrotest?

I know these question seems too junior but I do have confusion on it. your response is appreciated.

Thanks
Robert Liu Received on Wed Nov 13 11:28:00 2002