In March 2017, the Fire Systems Laboratory in conjunction with the Materials Durability Laboratory, conducted a corrosion test on a dry powder fire extinguisher in accordance with AS 1841.1.
Clause 6.7 of AS 1841.1 requires that fire extinguishers are exposed to a 5% neutral salt spray test for a duration of at least 480 hr. The Materials Durability team of Infrastructure Technologies operates several salt spray chambers which are capable of applying the conditions required by this test method. The laboratory conducted the salt spray test in accordance with AS 2331.3.1.
Following the corrosion test, Fire Systems conducted an Effective Discharge test in accordance with Clause 5.3 of AS 1841.1. This test involves the discharge of the fire extinguisher in several discrete steps, after each the mass of the extinguishing agent remaining in the cylinder is determined.
The corrosion and subsequent discharge test,was performed on a 4.5 kg Class ABE extinguisher. The first discharge was conducted for 9 s (minimum discharge time for the type and size of extinguisher in accordance with AS 1850), followed by complete discharge. The cylinder was subsequently disassembled to remove all remaining agent not discharged from the pressurised cylinder. By comparing the mass of the cylinder before and after each of the discharge steps, the nominal extinguishing agent mass (i.e. nominal charge), minimum discharge amount and total discharge amount was calculated in accordance with Appendix D of AS 1841.1.