[PSUBS-MAILIST] HP Scuba hose

[Jon Wallace via Personal_Submersibles]

I probably won't be changing the valve but a good point about the burst disk.  I don't recall what George used in the K600 to tap off the air cylinder so just thinking on my own here.  I like the idea of a flexible hose going to a manifold rather than a rigid pipe system that requires everything line up perfectly to the tank.

      From: Sean T. Stevenson via Personal_Submersibles <personal_submersibles at psubs.org>
 To: personal_submersibles at psubs.org 
 Sent: Sunday, March 11, 2018 1:39 PM
 Subject: Re: [PSUBS-MAILIST] HP Scuba hose
   
Just to add to that - SCUBA cylinder valves typically incorporate burst disc safety devices into a port in the valve body. If you're contemplating removing a cylinder valve to plumb to a cylinder directly, you will need to add a safety pressure relief mechanism elsewhere.

Sean



-------- Original Message --------
On Mar 11, 2018, 10:26, Sean T. Stevenson via Personal_Submersibles < personal_submersibles at psubs.org> wrote:


Well, SCUBA cylinders are usually supplied with valves with either CGA-850 or DIN 477 orifices, and you can find connectors / adapters for both to adapt directly to either gender NPT, and if you don't need the cylinder valve, in North America the cylinder neck threads are likely 3/4-14 NPS, which you can also tie into directly if that suits your application.

Sean

-------- Original Message --------
On Mar 11, 2018, 10:15, Jon Wallace via Personal_Submersibles < personal_submersibles at psubs.org> wrote:

Is there some other way to tap HP off a SCUBA tank other than first stage regulator?  I was thinking of running the HP hose to a manifold that would feed the ballast tanks.

      From: Sean T. Stevenson via Personal_Submersibles <personal_submersibles at psubs.org>
 To: personal_submersibles at psubs.org 
 Sent: Sunday, March 11, 2018 10:54 AM
 Subject: Re: [PSUBS-MAILIST] HP Scuba hose
  
HP SCUBA regulator orifice is 7/16-20 UNF 2B thread. There are Swagelok and other fittings which will work, but watch your wrench clearances when using multiple adjacent ports. On that note, LP SCUBA ports are either 3/8-24 UNF - 2B (most common) or 1/2-20 UNF - 2B (less common). Be aware that while most HP SCUBA SPG hoses have a pinhole bore in order to reduce the consequences of a HP hose failure, some SCUBA regulators incorporate the pinhole restriction into the regulator itself, which will limit the available flow rate at high pressure. Of course, if your drawing gas off at high pressure anyway, why go through the reg?

Sean

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-------- Original Message --------
On Mar 11, 2018, 07:12, Jon Wallace via Personal_Submersibles < personal_submersibles at psubs.org> wrote:



Are there adapters that can change a SCUBA HP hose fitting to NPT?
Jon
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