Jeff Mack Posted November 14, 2006 Share Posted November 14, 2006 Went to the local welding shop to get a 1/4" flash arrestor for a blown burner I'm working on. The least expensive one they have is more than the rest of my burner put together. Anyone know of a reasonable source for the things? Thanks! Jeff Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 14, 2006 Share Posted November 14, 2006 SAY WHAT? If this is a propane burner why do you need a flash arrestor? There is no O2 in the line and *unlike* acetylene propane cannot burn without O2. (Actylene can exothermically dissassociate without *any* oxidizer present!) There is no high pressure O2 from an oxytank that could feed back into the gas line making a combustible mix. Why exactly are you trying to install this? Someone confused between Acetylene torchs and Propane forge burners? Thomas Quote Link to comment Share on other sites More sharing options...
Jeff Mack Posted November 14, 2006 Author Share Posted November 14, 2006 I assumed there was enough o2 in the blown air to sustain a fire. I'm definatly not an expert on that kind of thing. I thought I had read it was a good idea. Was also worried that running a tank almost out could lower the output pressure enough to create an opportunity for disaster with a blower pushing from the other end. Since I am an office dweller most of the day, and don't work around this stuff except when I play, I tend to over engineer to the point of paranoia, but I figure that is better than going ka-boom. Jeff Quote Link to comment Share on other sites More sharing options...
Woody Posted November 14, 2006 Share Posted November 14, 2006 Jeff: The reason that a flash arrestor or blow back valve is needed on O/A equipment is because of two factors. 1. The fact that Oxygen is supplied to the system at a higher pressure than the Acetylene which can allow oxygen to be blown back into the Acetylene side. 2. The inherent unstable nature of Acetylene which has a flammable range from 2.5% to 100%. There is no danger of sucking air back into a propane bottle by running it empty. Once the pressure in the bottle is equal to the air pressure outside the bottle, flow from the bottle will stop but there is no way that outside air could be forced back into the bottle. Therefore a spark arrestor is not needed on a propane forge. Woody Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 14, 2006 Share Posted November 14, 2006 Ok Jeff; it's good to be cautious I was just afraid some shopkeeper was trying to sell you a bill of goods---as you noticed they are a tad on the high side and as it's not needed no reason to choke your wallet anymore than you have to. OTOH I consider them MANDATORY on an OA set... Thomas Quote Link to comment Share on other sites More sharing options...
Jeff Mack Posted November 15, 2006 Author Share Posted November 15, 2006 Thanks Woody and Thomas! Glad I asked before I spent. Jeff Quote Link to comment Share on other sites More sharing options...
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