Using European 3/4.14" valves in the US?

[broadreach]

Hi,

I'm moving to the U.S. (California) from Europe and considering bringing a European H valve with me. Since my regs are all DIN, it seems that it would be easier to just bring my (almost new) valve along rather than having to purchase a new one in the U.S. to replace the single Yoke valve that would probably come with any used tanks sourced locally.

Can anyone look at the specs of this valve and tell me if it would fit the average U.S. tank?

Markings on Valve:
3/4.14" (this is very unusual for Europe, but my tank is old)
WP 232 Bar
CE 1370
13-05/187
SOS 10126

See photo attached.

Thanks!

 

[Scared Silly]

If indeed it is a 3/4-14 threaded valve you will be fine using it in cylinders sold in the States.

The big issue is when 3/4-14 and 25mm valves get interchanged.

 

[knotical]

I think you should also determine whether the threads are Whitworth, which is very close, but still not a match.

 

[broadreach]

I think you should also determine whether the threads are Whitworth

hmmmmmm I am not sure how to determine this. I have sent an inquiry to the shop who sold me this valve (in Genoa, Italy). Let's see if they can answer this question. FWIW the valve is very new. I'm guessing that the 13-05 means that it was made in May 2013.

Can anyone determine the answer to this question from the marking on the valve?

Thanks!

 

[steveharriss]

A European cylinder is most likely a G3/4 (3/4 BSPP) thread in the neck whilst the US cylinder will be 3/4 NPSM. Both have a pitch of 14 threads per inch BUT these are not the same and NOT interchangeable.The thread angles are different, NPSM 60 degrees and G3/4 55 degrees, and you would be creating a potential gun if you managed it. The G3/4 valve will go into the NPSM neck but would be tight and bind in areas. Please sell your old valve and buy a new US specification valve.

DO NOT put this valve into a US specification cylinder.

 

[ajduplessis]

European cylinders to my knowledge have M25x2 threads and not 3/4 threads. The M25 valve will screw into 3/4 thread but due to the thread angles will only have 20% contact making them extremely dangerous. Please make 100% sure they are compatible.

 

[steveharriss]

Modern European cylinders have M25 neck threads, older cylinders have G3/4 threads. Neither a G3/4 nor 3/4 NPSM threaded valve can fit into the neck of an M25 threaded cylinder so the fact that there is a 3/4 valve screwed in means that it is not M25. An M25 valve can fit into both a G3/4 and 3/4 NPSM threaded cylinder but brute force is needed to drive it home as they start loose and then bind as they are fitted.

This is why cylinder necks and valve threads should be fully checked with go/no go plugs and rings before being fitted.

Trouble is so few people actually know what they are on about..... even some supposed shop technicians!

 

[elan]

Does the valve have a burst disk?

 

[steveharriss]

It's CE marked so it does not have a burst disc.

 

[broadreach]

The dealer has confirmed that the valve is NPSM thread. You have to remember that it is sitting in a Faber steel tank from 1978 and was specially ordered to fit this tank.

I am look into the burst disc question next. Is it mandatory to have burst discs in the U.S.?