New member here.  I'm trying to find info on whether back flow and flash arrestors are required on small hand gas/air torches, ones typically used for arts & crafts.  The back flow devices I've seen typically require more of a pressure drop (~5#) then is present for these torches (~2#).  I was checking OSHA regs, but couldn't find an exemption or anything for these small torches.  Is there and AWS standard that I could check, or does someone know of an OSHA interpretation letter?

Any help would be appreciated.  Thanks.