Can i fill my scuba tank with nitrogen?

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I am in need of a nitrogen tank that is equipped with a cga 580 valve.  I have in my possession a CGA 580 valve, and a scuba tank.  The scuba tank has 3/4" female NPSM threading.  The cga 580 has 3/4" male NPT threads.  I would like to put the cga 580 on the scuba tank and fill it with 2400 psi nitrogen.  I have found online that these two thread types are compatible.  Do you guys see any reason why this wouldn't work?  Thanks in advance for the replies.Brad
Reply:Ain't 2400psi a little stout for a scuba tank?Rex
Reply:The big question is will any distributor fill a scuba tank with nitrogen?  I really doubt it.
Reply:Originally Posted by rode2rouenAin't 2400psi a little stout for a scuba tank?Rex
Reply:Originally Posted by rode2rouenAin't 2400psi a little stout for a scuba tank?
Reply:U need new label on the vessel just in case someone wanted to borrow without yur permission. Nitrogen is used for toy gun refill?Unit in my fab shop dept:my good hand and team that trust me...A lone welder make art... a village full of welder make Miracles...
Reply:Originally Posted by rode2rouenAin't 2400psi a little stout for a scuba tank?Rex
Reply:Well, jumping off the back of a boat, with a regulator in my mouth; hoping for AIR when I SUCK for oxygen.................. OK, I don't really know what the regulations are. 9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:Originally Posted by bgood44I am in need of a nitrogen tank that is equipped with a cga 580 valve.  I have in my possession a CGA 580 valve, and a scuba tank.  The scuba tank has 3/4" female NPSM threading.  The cga 580 has 3/4" male NPT threads.  I would like to put the cga 580 on the scuba tank and fill it with 2400 psi nitrogen.  I have found online that these two thread types are compatible.  Do you guys see any reason why this wouldn't work?  Thanks in advance for the replies.Brad
Reply:The NPT thread is indeed "compatible" with the NPSM thread, in that it will screw into the tank, BUT, NPT threads will only seal with NPT and NPTF threads.Inserting an NPT nipple into an NPSM collar will result in the threads binding only at the largest diameter, which will form an extremely weak connection that will not seal, but would also probably give way under pressure.  In fact, NPSM threads are not designed to bind, do not seal by themselves (unlike NPT threads), and require some other form of sealing (O-ring, mating cones, etc.)I'm sure someone on the internet will say that this would work, and I'm sure it will seal for low pressures, BUT forget about it for this kind of pressure.Don't get totally discouraged by this though.  Argon is frequently used in SCUBA dry-suits, and is used with a CGA-580 valve as well, so you might be able to find a CGA-580 valve with the correct NPSM threads and o-ring.
Reply:Originally Posted by rlitmanDon't get totally discouraged by this though.  Argon is frequently used in SCUBA dry-suits, and is used with a CGA-580 valve as well, so you might be able to find a CGA-580 valve with the correct NPSM threads and o-ring.