High Flow Regulator Mounted 3 Function Flash Back Arrestor - Multiple Use.
Reduced Pressure Drop.

In addition to the increased flow rate possible when using "standard gas equipment"  the larger and higher flow flashback arrestors (FBA) presents less of a flow restriction which makes these larger FBA very useful when you need to operate at a higher working pressure, this is because the FBA presents less of a pressure drop to the system / nozzle which allows for correct and safer operation of the process.  The larger higher flow flashback arrestors are also a must when operating with long hoses, the pressure drop is much greater, which is simply due to the length of hose.  Therefore it is good practice to fit larger higher flow FBA to minimise the pressure reduction.  Long hoses should always be as large a bore as possible, again to minimise the pressure drop, a smaller bore working "whip end" may be fitted.  Ensure the hose check valve does not reduce the flow / induce a pressure drop, HCV must be marked with the BSEN5175-2 (or BSEN730-2) standard.

FBA connections
Special purpose high flow flashback arrestors stocked with G3/8 connections but are available with G1/2 connections if required.  (Flow capacity is the same).

German manufactured FBAs have 3 functions:-
"FA"  Flame Arrestor  - The first is the flame quenching element which is of course a sintered metal filter which absorbs the heat from a flashback (when the conditions are within the design parameters)
"NV" Non Return Valve - The second function is that these regulator mounted FBA incorporate a non-return valve to prevent the back feeding of gases, the primary cause of flashbacks.
"TV" The third and final element to this flashback arrestor is the thermal cut off valve which is activated by heat. This thermal trip is a final fail safe designed to cut the incoming gas supply off permanently.
The thermally activated cut off valve is not and will not be triggered by experiencing a flash back alone. An external fire or an internal fire would cause the valve to close, helping to prevent further damage, by shutting off the incoming gas.

These flashback arrestors may be used continually even when having suffered many flashbacks, these flashback arrestors do not require resetting.  Resettable higher flow FBA are available.

Causes of Flashback
Should you be unfortunate and experience a flashback then it is important to investigate why, this is so you may prevent any future problems from occurring.
The primary cause for the majority of flashbacks will be due to incorrect lighting up procedure and failure to purge the gases properly. 
Remember, long hoses require extra purge time.
The second most common cause is lighting up with too low a fuel gas flow combined with a leaking oxygen valve.
When you light your nozzle, and it goes "BANG" that is wrong and should not happen, ever, no matter what nozzle or gases are being used.

Therefore - check your gas equipment for - damage - for leaks et cetera before lighting up and then light up correctly.  If you need advice please give Noz-Alls a call on 01242 681052.