What is the pressure limit during hydrostatic testing of water-type cylinders?

For stored-pressure water and foam fire cylinders, the hydrostatic test pressure is 30 kg/cm² (approx. 430 PSI), maintained for at least 2.5 minutes. You can verify if the test was conducted by looking for the mandatory stamp on the cylinder collar or body showing the date of the test and the license code of the testing agency.