An open-close test is a functional test for in-tank valves used as drain valves.
Flame arrester Device fitted to the opening of an enclosure, or to the connecting pipe work of a system of enclosures, and whose intended function is to allow flow but prevent the transmission of a flame. In this case, their operating position is NC (normally closed). In this test, the in-tank valve In-tank valve An in-tank valve is located inside a storage tank and is open under normal working conditions. is opened once and closed again.