FST valve testing machine consists of two major systems, i.e. liquid testing system and gas testing system, and it is used to conduct tests of flanged safety pressure reducing valves (Φ2”~ Φ12”) and a variety of threaded connection valves (1/2″ 3/4″ 1″ 1 1/4″ 1 1/2″ 2″NPT) as well as ordinary thick/thin flange safety pressure reducing valves.