(1) All valves and internal parts shall be removed and the extinguisher emptied.

(2) All traces of extinguishing material shall be removed from the inside of dry chemical and dry powder type shells before filling with the test liquid.

(3) The cartridges, and some cartridge receivers of dry chemical and dry powder extinguishers having externally mounted gas cartridges, shall be removed and a suitable plug inserted into the shell opening at the point of removal.

(4) All hose shall be removed from cylinders prior to hydrostatic testing.

(5) On all wheeled dry chemical, dry powder, halogenated agent, AFFF/FFFP, and carbon dioxide extinguishers equipped with a shutoff nozzle at the outlet end of the hose, the hose (complete with couplings but without the discharge nozzle) shall be removed and tested separately.

(6) On all wheeled stored pressure dry chemical extinguishers, the head assembly is to be removed and be replaced with a suitable test bonnet.

(7) The hose of the hydrostatic test pump is then attached by the flexible connection to the discharge nozzle, hose assembly, test bonnet, or test fitting, as is applicable. In the case of wheeled dry chemical and dry powder extinguishers, procedures and fittings should be those recommended by the manufacturer.

(8) The test liquid supply to the test pump is to be turned on and the extinguisher then filled to the top of its collar. Air or other gases shall not be used as the sole medium for pressure testing.

(9) For extinguishers tested with their cap in place, the cap must be tightened SLOWLY while the test liquid supply remains open. When all of the entrapped air within the shell has been bled off and after test liquid emerges, the cap must be tightened fully.

(10) For extinguisher tested with a test bonnet or fitting, the bonnet or fitting must be tightened FULLY while the water supply remains open. When all of the entrapped air within the shell has been bled off and after test liquid emerges, the vent must be closed tightly.

(11) Pressure is then applied at a rate-of-pressure rise so the test pressure is reached in not less than 30 seconds. This test pressure is maintained for at least 30 seconds. Observations are made at this time to note any distortion or leakage of the extinguisher shell.

(12) If no distortion or leakage is noted and if the test pressure has not dropped, the pressure on the extinguisher shall be released. The extinguisher is then considered to have passed the hydrostatic test.

(13) All traces of test liquid and moisture must be removed from all dry chemical, dry powder, and halogenated agent extinguishers by use of a cylinder dryer. If a heated air stream is used, the temperature within the shell must not exceed 150° F (66° C).

(14) Any extinguisher shell that fails this hydrostatic test must be destroyed by the owner or at the owner's discretion.

(1) The discharge nozzle must be removed from the hose assembly without removal of any hose couplings.

(2) For dry chemical and dry powder types, all traces of dry chemical or dry powder must be removed.

(3) The hose must be completely filled with test liquid before testing.

(4) Pressure is then applied at a rate-of-pressure rise to reach the test pressure within one minute. The test pressure is to be maintained for one full minute. Observations are then made to note any distortion or leakage.

(5) If no distortion or leakage is noted, or the test pressure has not dropped, or the couplings have not moved, the pressure is then to be released. The hose assembly is then considered to have passed the hydrostatic test.

(6) Hose assemblies passing the test shall be dried internally. If heat is used for drying, the temperature shall not exceed 150°F (66°C).

(7) Hose assemblies failing a hydrostatic test must be destroyed by the owner or at the owner's discretion.