Re: [PSUBS-MAILIST] Pipe System Confirmation.

On 15 March 2012 15:05, <JimToddPsub@aol.com> wrote:

James,

Thanks for that first link in particular. It seems they (Undersea, Ltd.) have almost everything you would need to plumb a sub, but what really caught my attention were the high-pressure manifold bars and manifold assemblies.

Jim

In a message dated 3/15/2012 8:57:14 A.M. Central Daylight Time, jamesf@guernseysubmarine.com writes:

hi Alec\All,

Sorry for late reply, I took the day off yesterday to knuckle down to more sub work.

Alec, thanks for the offer of the manifold. Don't worry about it for now as i think i know what im going to make, but you never know. Don't throw it out!

Ive also found a pressure regulator that i think may work. Have a look at this link and see. About 3/4 of the way down. The 7000 series. Suspect its expensive. They also have manifolds and all sorts of things.
http://www.undersea.uk.com/catalogue/catalogue.pdf

Also found this one.

http://www.nuvair.com/store/paintball-accessories.shtml

The "rules of thumb" is great advice. Thanks Hugh.

Alan, The tanks are 232bar scuba tanks. I'll test the manifold to 300. I am going to reduce the outlet pressure using a regulator. Which one and pressure ratings ive not fully decided yet. Depends on the valves. The standard ptfe sealed ball valves ive used for ecerything else have a max working pressure of 69bar. But i might get something else and run the system higher.

Point noted about the small orifice on the HP port for the scuba 1st stage. I'll try it and see. Easy enough to pipe it directly to the tank if need be. Or i could drill out the orifice a bit.

Thanks everyone for the advice.

Regards

James

On 14 March 2012 00:42, Alan James <alanjames@xtra.co.nz> wrote:

Hi James,

I'm getting a bit lost here. You are talking about 1000 psi max, is that all the pressure

you can put in your tanks or do you have a regulator reducing down to 1000 psi.

I'm wondering if you could place washers under the spring in the 1st stage regulator to

give you more than the standard 130-150 psi above ambient out of the low pressure ports.

If you bumped it up to 200 psi then you would have more pressure than required to blow your

ballast at the maximum depth.

Regards Alan

----- Original Message -----

From: James Frankland

To: personal_submersibles@psubs.org

Sent: Wednesday, March 14, 2012 6:40 AM

Subject: [PSUBS-MAILIST] Pipe System Confirmation.

Hi All.

1. Does everyone else keep getting spam messages from Scott Waters?

2. I have finalised my HP air system. Ive probably made a meal out of something relativly simple but i havent ever built a HP system like this before so have had to figure it all out.

The system will be designed to route as per K350 design but use swagelok fittings and run at higher pressure. The system is designed to opperate at a max pressure of 1000 psi but will run normally at lower. Most of the system will be 1/4 inch pipe, with just the variable tank inlet\vent part 1/2 Inch.

The limitation on the design is the worcester ptfe sealed ball valves which have a maximum working pressure of 1000psi (69bar).

I have 2 last questions.

1. I have decided to use worchester ball valves (466TSE ptfe sealed) instead of the diaphragm valves or even needle valves. Do you think this will be ok?

2. Does anyone have any suggestions for the thickness for my 300bar manifold.

I am going to make a 4300psi (300bar) stainless manifold to accept the tanks.

The manifold will have 2 x standard scuba quick release high pressure hose fittings. Like you would use for a BCD or gauge off your 1st stage. This means i can run 2 tanks to the system but be able to get them on and off easily and quickly.

There will be a 300 bar gauge attached to the top of the manifold to measure manifold inlet pressure, a manual relief valve off another port and then the outlet which will go to a 300bar - 70bar pressure reducing regulator with inline gauge to measure system pressure.

Emile says that the HP port on a normal 1st stage does not give a lot of flow, so i am going to just run it and see if its enough. If not, i can pipe the manifold directly to the tanks.

The idea with this is that 1, the 2 x tanks can come off easily and 2, i have adjustable high pressure outlet.

Sorry, after all that, the question is. Any suggestions for thickness of the manifold to hold at 300 bar? I think i might go to my local dive shop and measure the thickness of their filling station manifolds. hmm, good idea.

Thanks as always,

regards

James