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TeamDoug2015
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J Valve or Paper Weight

Fri Jul 10, 2020 8:17 am

I've serviced plenty of the USD Black plastic-knob variants of the standard J-valve, but I have before me the all-chrome version with a what a looks like a 1/2" thread burst disk assembly.

Before I start in on servicing this J-valve, I wanted to ask if anyone could point me to a source of replacement disks for 3000 psi operating pressure?

If I can't easily get some disks, it's destined to become a paperweight.
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luis
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Re: J Valve or Paper Weight

Fri Jul 10, 2020 10:46 am

Yep, from what I remember that will become a paper weight. I am fairly sure that others have tried to find a source for that size burst disc with no success.


I am just curious, are you required to have a burst disc in Singapore?

I personally like having valves with burst disc (and it is required in the US). The burst disc can be a big safety device if the cylinder is in a fire. And here we build our houses out of the same fuel we sometimes use to heat them: wood. :shock: :P

If you are not concern about fire and are not required to have a burst disc, you could just use a bolt. I don't recommended it, but I know of many divers in Florida cave country that do it all the time.

Finding a different valve is the best solution, IMHO.
Luis

Buceador con escafandra autónoma clásica.

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TeamDoug2015
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Re: J Valve or Paper Weight

Fri Jul 10, 2020 12:41 pm

I had considered just dropping in a stainless steel blanking plug and a washer, as I do with my valves in Europe. But I don't even have a stock of blanking plugs that would fit. Thanks for the bolt idea - I'll remember that.

But notes from Singapore - Yes, almost all of the tanks here are US DOT and the valves sport functional burst disks. These folks are very much rule followers, so putting a bolt in the valve would probably cause someone to have an aneurysm at my fill station.

I don't know if it was the case in the early days, but the coin of the realm here currently is the AL80, mostly Luxfers with various valves, mostly Thermo. Wholesale price for a hydro test is US $46 and I've not seen many vis stickers. A retail hydro is $95. Makes me miss my $7 hydros in Virginia Beach, just outside of the Navy Base. Nobody seems to check anything other than the hydro - like Europe.

If someone has a USD J-Valve with a 3/8 burst disk that they would throw into a small flat rate box, please let me know.

Thanks,

Doug

James
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Re: J Valve or Paper Weight

Fri Jul 10, 2020 7:25 pm

Trident shows a 1/2 inch 3k burst disc on Amazon: https://www.amazon.com/Trident-3000-Bur ... 404&sr=8-2
Would that one work?
Respectfully,
James

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luis
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Re: J Valve or Paper Weight

Fri Jul 10, 2020 7:44 pm

Wow, it should.

Now I wondering if I was thinking of a different size.

I thought there was a large sized burst disc that was not being supported anymore. I just can't remember what the size might have been. I will have to do some searching.

Thanks
Luis

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luis
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Re: J Valve or Paper Weight

Fri Jul 10, 2020 8:33 pm

I did a bit of searching and I found several sources for the 1/2" burst disc.

I don't know what size I was thinking about.
Luis

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TeamDoug2015
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Re: J Valve or Paper Weight

Sat Jul 11, 2020 12:17 pm

Thanks - I think I found a source for 1/2 inch burst disks.

Because it will take a while to get the burst disks out to Singapore, I went out and picked up a 1970's Dacor tank this evening with a classic J-valve for $16 I found on of the local equivalent of Craig's list.

The gentleman who sold it to me said he was the original owner and indeed it had a plug in place of the burst disk. I'll upload a photo tomorrow for anyone who cares about such things.

Thanks for the advice.

Doug

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SurfLung
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Re: J Valve or Paper Weight

Mon Jul 13, 2020 11:41 am

My friend "Rich 50,001 Questions" has a valve with the 1/2" burst disk. It was on a 2250 psi tank and we think the LDS overfilled it... It blew and that's how we found out how hard it is to find the 1/2" burst disks. I think SeaHunt Jerry had one he gave to Rich but it was old an perhaps had been installed before. Anyway, Rich hasn't trusted it and ended up switching valves. I'll tell him about the Trident link... Thanks for the tip. :)
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