Pipeline vent and drain points shall have additional screwed plugs or blank flanges as appropriate for the test. The test fixture for admitting the test fluid shall include suitably rated valves for isolating the pipe network under test from the test fluid (water) source and draining the tank at the completion of the test. Water is typically introduced at the lowest point in the network and air vented from the highest point. Caution shall be taken to vent off entrapped air as the piping is filled and before it is pressurised.