1/2" to 3/4" Adapter Question's

[Graeme Tolton]

Sounds like this is going to continue in the accidents/incidents forum. Cylinders are not meant to be modified in any way. They are made out of one solid plate of metal. Exactly enough metal to meet requirements. Remove ANY of this metal, the tank no longer meets manufacturer's specs.. Modifying a tank OR a valve is a recipe for disaster (if you can find someone who will fill your creation). If you can't find the right valves for the tanks, cut your losses. No sense being responsible for a fill station accident over a couple hundred dollars worth of equipment.

 

[WD8CDH]

Properly made adapters are not a problem, either from legal or a safety standpoint. Modifying the tank is a no-no from the legal standpoint and usually from a safety standpoint too.

The only off-the-shelf adapters that I know of specifically made for 3000 psi and more that would fit tanks that you might come across would be from a 3/4" tapered pipe thread tank to a 1/2" tapered pipe thread valve or manifold. That combo is easy to find.

Many other combinations are possable to build but not off-the-shelf.

 

[oxyhacker]

Actually, while modifying the tank neck or threads is a no-no, and extremely dumb abd dangerous, there doesn't seem to be anything in the regs against modifying the valve itself. In fact, Sherwood used to run of batches of different oddball valve sizes and threadings, simply by taking a standard 3/4-14 valve and recutting the desired threads, be they tapered or straight, on it. Anyone thinking of emulating this should know how to cut a acceptable thread, and be sure the threads are good, snug fit, but it's not rocket science.

Oh, and not all tanks are made out of plate - alu tanks are made of ingots, and spun tanks from tubing. Deep drawn steel tanks, though, are made out of steel plates, and usually have a little extra meat over the minimum, to allow for tumbling, and irregularities in the manufacturing process.

Sounds like this is going to continue in the accidents/incidents forum. Cylinders are not meant to be modified in any way. They are made out of one solid plate of metal. Exactly enough metal to meet requirements. Remove ANY of this metal, the tank no longer meets manufacturer's specs.. Modifying a tank OR a valve is a recipe for disaster (if you can find someone who will fill your creation). If you can't find the right valves for the tanks, cut your losses. No sense being responsible for a fill station accident over a couple hundred dollars worth of equipment.