Importance Of Hydrostatic Testing In Fire Extinguisher Cylinders Maintenance

Hydrostatic Testing

Hydrostatic testing is a measure usually adopted to test and certify the state of a fire extinguisher cylinder; if it is in a good or bad condition.

What Is Hydrostatic Testing

In general terms, hydrostatic testing is a type of test performed to determine the integrity and soundness of pressure vessels; it is also used to detect any form of leakage.

In respect to fire extinguishers, this testing is mostly used to test the physical integrity of the extinguisher cylinder to prevent any form of leakage of the extinguishing agent.

Leakage of an extinguishing agent will automatically render the fire extinguisher non-operational; a non-operational extinguisher will definitely disappoint in case of any fire emergency.

How To Carry Out Hydrostatic Testing

This testing can be done in these few steps:

  • The vessel (cylinder) is filled with an incompressible liquid – usually water or oil.
  • Pressure is applied to examined for leaks or permanent changes in shape. The pressure applied is measured using the pressure guage.
  • Red or fluorescent dyes may be added to the incompressible liquid to make leaks easier to see.

Read Also: 10 Tips For Safe Storage of Gas Cylinders


The test pressure is always considerably higher than the operating pressure to give a factor of safety. This factor of safety is typically 166.66%, 143% or 150% of the designed working pressure, depending on the regulations that apply.

If the LPG cylinder fails the hydrostatic test, it should be put out of use immediately or scrap to prevent re-use.

Hydrostatic Testing Standards

See a PDF copy of the hydrostatic test standards here

Also, you can watch a video on how the hydrostatic test is carried out. Though the video is not in English, but its self-explanatory.


Read Also: Safety precautions for the use of gas cylinders


How Much Does a Hydrostatic Test Cost?

The cost of hydrostatic testing usually depends on the extent of the plumbing system being inspected. Most hydrostatic tests cost between $250 to $500. Bigger plumbing systems can cost thousands of dollars to be inspected.