ANSI/ISA-75.19.01, from the American National Standards Institute and the International Society of Automation, provides requirements for the hydrostatic testing of control valves.


ANSI/ISA-75.19.01 applies to all control valves. It establishes the requirements for the structural integrity and leak tightness of the valves’ pressure retaining parts.

Test Procedures

In a hydrostatic test, the valve body is filled with testing fluid and then pressure is applied for a specified length of time. The valve is then inspected for any leakage.

Learn more about valve leakage tests.


The testing liquid can be water, water with a corrosion inhibitor, or another liquid whose viscosity isn’t greater than that of water.


The testing pressure depends on what material the valve is made of: steel, nickel-base alloy, cast iron, and so on. See the full standard for material-specific hydrostatic test pressures.


The test duration depends on the nominal valve size and valve class.

Nominal Valve Size Class 150 & Lower Class 250 to 600 Class 900 to 1500 Class 2500 & Higher
2” & Smaller 1 minute 1 minute 2 minutes 3 minutes
2 ½” to 4” 2 minutes 2 minutes 4 minutes 5 minutes
5” to 8” 2 minutes 3 minutes 5 minutes 8 minutes
10” & Larger 3 minutes 5 minutes 8 minutes 10 minutes

Acceptance Standards

Three conditions can cause a valve to be rejected:

  • There is visible leakage in the valve body assembly.
  • There is leakage through static seals and gasketed joints (unless allowed by design).
  • The hydrostatic test causes any distortion that impairs the valve operation.

A full copy of ANSI/ISA-75.19.01 can be purchased from the American National Standards Institute.

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