Production flashback test of safety devices
conforming to EN ISO 5175-1

A production flashback test is to be carried out after manufacture on all safety devices conforming to EN ISO 5175-1. The gas mixture and the pressure for testing the flashback arrestors depend on the gas application and the maximum operating pressure.

This diagram shows the set-up of the test equipment:

Flashback Test ISO5175 

1 - Flame detector
2 - Inlet pressure p1
3 - Sample
4 - Outlet pressure p2
5 - Steel tube
6 - Ignition

For connections up to G3/8, a steel tube with an internal diameter of 10 mm shall be used. For connections larger than G3/8, the steel tube shall be equal to the nominal outlet bore of the safety device.

Gas type
Test pressure Test mixture volume fraction in % of fuel gas in oxygen
1.5 bar 32% to 35% Acetylene
LPG maxiumum operating pressure 13% to 15% Propane
Hydrogen maxiumum operating pressure 40% to 50% Hydrogen
other fuel gases maxiumum operating pressure 80% to 90% of stoichiometric mixture

The test pressure, the gas mixture and the inner diameter of the steel tube are the decisive factors for the flashback test. The flashback test on the single safety device has to be done on the basis of the intended use of the unit. That means that only especially designed and tested safety devices are to be used for applications requiring higher working pressures or larger inner diameters of the steel tube.

Besides the BAM as an independent institute, IBEDA is able to carry out such flashback tests.