FLASHBACK ARRESTOR FOR FUEL GAS HOSES
A non-resettable flashback arrestor for use with Acetylene or Propane fuel gases with 3/8 BSP LH connections. Fitted next to the regulator and before the fuel gas hose, a flashback arrestor is an essential safety device when using oxy fuel equipment.
The main function of the flashback arrestor is to prevent gas mixtures occurring with potentially very dangerous consequences. An FBA (Flashback arrestor) should be fitted to both the Fuel gas and Oxygen hose lines. A fuel gas FBA has a left hand thread, whilst Oxygen flashback arrestors have a right hand thread. The difference in thread direction being another safety device to stop a mix up of equipment and potential gas mixtures being possible.
The flashback arrestor incorporates a pressure sensitive cut off valve or a non return valve, plus a temperature sensitive cut off valve.
These particular flashback arrestors are classed as non resettable. If the FBA is triggered due to an internal temperature cut off, it will no longer be useable and must be re-placed. They will withstand a series of minor flashbacks but will not react as a consequence of external heat though. For resettable flashback arrestors, please see our associated listings.
Flashback system consists of:
- Non Return Valve (prevents reverse flow of gases)
– Flash-back extinguisher
– Gas shut-off
- The non-return valve prevents gas from flowing in the wrong direction i.e. from torch to the gas source.
- The flash-back extinguisher stops and extinguishes a back fire in the event of a flash-back.
- The gas shut-off interrupts the supply of fresh oxygen and fuel gas to the torch.
For all systems with hoses well in excess of 3 metres long and/or hoses greater than 6.3mm bore, a second flashback arrestor should be considered at the torch end. A check valve (non-return valve) should also be fitted on the hose on the torch side of the system.
A potentially serious occurrence where a detonation takes place within the system and a high velocity pressure wave is generated.
The ‘explosion’ may cause damage to the system.
A flashback explosion propagating back into an Acetylene cylinder can lead to very serious incidents.
- Failure to purge equipment (90% of all flashback incidents are caused by failure to carry out a purging procedure)
- Faulty or damaged equipment
- Incorrect light up procedure
- Wrong size, blocked or dirty nozzle being used
- Incorrect pressures set
- No hose check valves
- Kinked or trapped hoses
- Failure to undertake routine maintenance.