DIN Valve Thread repair?

[WetDawg]

Got a DIN valve that has been "slightly" cross-threaded. I say "slightly" only because you cannot see nor even feel any anomaly, however the reg only gets about 2 turns in before it stops. Any experience on here with chasing threads with a tap?

If so, what size tap will do the trick?

 

[kierentec]

have you ever dropped the cylinder on the valve, or let it roll around in the back of a truck? it's likely that the valve got "dented" somehow. inspect the outside of the valve and see if you can find any deformities.


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[Jxh2297]

A new valve for 40 bucks would do the trick

 

[Scared Silly]

have you ever dropped the cylinder on the valve, or let it roll around in the back of a truck? it's likely that the valve got "dented" somehow. inspect the outside of the valve and see if you can find any deformities.

I am going to second this opinion. Folks forget that valves are brass which is soft. I bet the valve is dented given you only got the reg screwed in two turns. Even with straight threads the first couple of threads are slightly tapered/cut to allow the threads to engage correctly.

 

[ajduplessis]

I would NOT re-tap the thread. Buy a new or even secondhand one.

 

[Peter_C]

The tap will probably cost almost as much as the valve.

 

[j2s]

Ditto with all who have said replace it...Not worth trying to fix it... And you may find that the new one does not properly fit the 1st stage which uncovers more problems that should be addressed.........

 

[Jim Lapenta]

Buy a new valve. 40 used and maybe 60 new for a convertible.

 

[Wookie]

I agree with the above posters, but just so you know, your tap would be a G 5/8-14 bsp whitworth thread. Good luck finding that tap.....

Edit - the tap is available here: For $133. You can buy a lot of used valves for that....

 

[Colliam7]

Got a DIN valve that has been "slightly" cross-threaded. I say "slightly" only because you cannot see nor even feel any anomaly, however the reg only gets about 2 turns in before it stops. Any experience on here with chasing threads with a tap?

I will echo the comment that the problem may be something other than cross-threading - specifically a malformation of the valve aperture. I recently had a similar problem, and used a stainless steel DIN Sealing Plug as a tap - it is harder than the brass. I worked it into the opening and gradually threaded it all the way in. The challenge is to do it gradually, so the the valve metal does not rupture. In essence, you are reshaping the valve metal. So, get a plug and a really big crescent wrench and have at it, slowly.

For those who recommended a new valve - in principle, and as a general rule, I agree with you. It is the easiest, and least expensive solution. But, there may be reasons why it is not a viable alternative. As one example, if the tank is an older 3500 PSI HP steel tank, and you need a left hand modular valve with 7/8" UNF threading, you might have better luck finding a tap to fit it than a new valve.