Sea Elite Manifold and DIN plugs?

[rsanders]

Apologies if this has been covered. I've seen plenty of threads on each, but not both together.

I just received my new Sea Elite 300 bar manifold today and was surprised by the absence of the small pressure relief hole usually mentioned in threads about the DIN plugs. I understand that this hole is pretty important for handling improperly seated first stages and for releasing any pressure built up behind DIN plugs when the valves are accidentally opened.

It's been mentioned in these posts:

Safety Hole
DIN plugs


The Thermo Pro valve I have on one of my tanks does have the hole. There is a small space between the end of the threads and the face against which the regulator's captured O-ring seals, and the hole is there. In the Sea Elite, the threads go all the way to the face with no hole apparent on either side.

Does anybody use SS DIN plugs with Sea Elite manifolds? Have you ever had to remove them after pressurization? And if so, were there ballistics involved?

thanks,
-- Robert

 

[pants!]

The O-ring is what seals the thing. As soon as the O-ring disengages, the relatively small amount of air contained in the valve escapes through the imperfect seal of the threads. By the time you back it out a turn or so the air is all gone and you can then turn with your hand. The holes might speed things up a little bit, but I haven't had any issues.

 

[rsanders]

As soon as the O-ring disengages, the relatively small amount of air contained in the valve escapes through the imperfect seal of the threads.

Thanks! That makes sense, but the posts about the little hole were pretty emphatic. And it's not an experiment I feel motivated to try. :bonk:

It seems like a solid piece of gear for an excellent price ($139 from Diver's Supply on eBay). There are a few small cosmetic flaws but if it's behind my head I don't much care how pretty it is. Can't wait to dive with it.

-- Robert

 

[Spectre]

The intent of the holes isn't to relieve pressure. But rather it's to make it so that you don't inadvertantly end up with a seal made in the threads when you put a 200 BAR reg on a 300 BAR valve. The 200 BAR DIN screw is shorter than the 300 BAR, and that hole is placed such that a 200 BAR reg won't reach it.

Mine get sealed on all the time, expecially on dive boats when people stand with their hands on valves as they watch the water. you just slowly unscrew it and the pressure drops as the airspace grows, until the seal releases. With my valves with the hole I have to be -very- careful unscrewing it, as when the pressure blows through that hole, it often time takes my o-ring out with it.

 

[rsanders]

The intent of the holes isn't to relieve pressure. But rather it's to make it so that you don't inadvertantly end up with a seal made in the threads when you put a 200 BAR reg on a 300 BAR valve.

That's part of what had me confused. Do the threads seal or don't they? (Depends on the amount of accumulated gunk?) If they do seal, then the hole seems necessary to enforce the prohibition against 200 bar regs on 300 bar valves. And a pressurized DIN plug would be a trickier thing to remove.

If the threads don't seal, then it seems like a 200 bar DIN regulator (or 232bar yoke insert) would leak enough to prevent use even without the hole, and removing a pressurized DIN plug wouldn't be a problem.

I suppose there's a difference between removing a DIN plug with the valve closed and trying to use a 200 bar regulator with the valve open. And maybe it's just a belt-and-suspenders thing.

Whatever the case, my newbie mind is at ease now. If it works, it works.

 

[pants!]

The threads leak enough to break the seal from a DIN plug, but well enough to potentially hold enoug pressure for you to think your 200 bar reg is fully seated..

 

[Spectre]

That's part of what had me confused. Do the threads seal or don't they? (Depends on the amount of accumulated gunk?) If they do seal, then the hole seems necessary to enforce the prohibition against 200 bar regs on 300 bar valves. And a pressurized DIN plug would be a trickier thing to remove.

It's conceivable that they might. I've not personally played around with it... but think about the wonderful fun if it did seal long enough for you to jar the reg when you hit the water

I think the fact that they don't often seal is the reason the holes aren't there in all regs.... since the problem would also be present if your o-ring went byebye and you didn't notice and put your reg on anyway.

 

[rsanders]

Well, having just now received the plugs, I think I can be pretty sure the threads won't seal. See the attached picture, and sorry for the fuzziness.

Note that these are brass DIN plugs I picked up on eBay, not the SS ones everybody else seems to be getting.

 

[Spectre]

Well, having just now received the plugs, I think I can be pretty sure the threads won't seal. See the attached picture, and sorry for the fuzziness.

Kinda defeats the purpose

 

[rsanders]

Kinda defeats the purpose

Well, though I haven't tried it yet, the O-ring on the end should provide a seal when the plug is fully inserted, and the channel cut across the threads should provide any residual compressed air a way to vent when the O-ring seal is broken.

It looks like a good design and an answer to all my questions, but I'm a computer guy and don't handle analog stuff all that well.

Oddly enough, I don't have nearly enough questions about actual gear like regulators. After reading the Airspeed Press repair manual, it all seems pretty straightforward