Hydrostatic testing tests valves are tested with inhibited water in accordance with API 6D and ISO 14313, to verify strengths of the main components such as the body, bonnet, ends and seats, and to prove the integrity of the valve's pressure retention envelope and seat sealing capability.

Hydrostatic testing is normally carried out using a non-hazardous liquid medium such as inhibited water at prescribed pressures. Both the body and the seats would be tested, and leakage can be measured by viewing the pressure gauge, or recording pressure over time on a chart recorder device