Excerpt of EN 3-7 – Chapter

8.2 Acceptance levels

Leakage from an extinguisher, or propellant cartridge, shall not exceed the following:

a) for stored pressure extinguishers a rate less than or equal to 6 % (v/v) of the expanded gas at 20 °C per year;

NOTE The volume of the expanded gas is the free volume of the gas at 20 °C;

8.3 Production leak tests

To test for conformity to 8.2a) and 8.2b), all extinguishers and propellant cartridges shall be tested. A rate of leakage greater than the limit specified in 8.2a) or 8.2b) shall result in the rejection of the extinguisher.

Technical Data:

Power supply:
400 V, 3 Ph, 50/60 Cy.
Air supply:
10 bar

Weight:

approx. 350 kg

Dimensions:

approx. 800 x 1600 x 1600 mm

leak test of fire extinguishers

For example by a 6 kg Stored pressure extinguisher:

Ø      Nitrogen volume = 3,666666 litre by 16 bar

Ø      Expanded Nitrogen volume = 58,66666 barlitre

Ø      Tolerated leak per year = 3,52 barlitre

Ø      Tolerated leak per second =0,0000001116 barlitre
       = 1,12E-7 barl/sec = 1,12E-4 mbarl/sec

Ø       by using of 3% Helium in the nitrogen the equipment will be able to measure this
       fine leak rate of 0,00000334855 mbarl/sec ( 3,34855E-6 ) mbarl/sec in one minute.