Hydrostatic testing is typically performed on pressure vessels such as pipelines, gas cylinders, boilers, and fuel tanks. These types of vessels are subjected to high pressures in normal operation, and hydrostatic testing is used to ensure that they are strong enough to withstand these pressures without failing or leaking.

Hydrostatic testing is also commonly performed on fire extinguishers, diving tanks, and other types of pressurized equipment. In these cases, the goal of the hydrostatic test is to ensure that the equipment is safe and ready for use, and to identify any defects or damage that may affect its performance.

Hydrostatic testing is usually carried out during the manufacturing process, before the pressure vessel is put into service. It can also be performed on existing pressure vessels as part of a regular maintenance program, to ensure that they are still safe and fit for service.