Scuba tank refill

[ferret_guy]

I was thinking of using a scuba tank to refill a galvinised steel pressure vessel for my next spud gun to enable quivk high pressure refills my questions are, has anyone tried this before? and how mutch pressure can threded galvinised steel take?

[jsefcik]

steel can with stand, thousands of psi, extreme high pressure. they why alot of hybrids are made of steel

[ferret_guy]

Are we talking 1,000-1,500psi or is it high enough to use straight 4,000psi air from the scuba tank

[Goats spudz]

I wouldn't suggest doing that, use Steel Hydraulic tube or Seamless stainless steel, Jsefcik hybrids only encounter high pressure for a matter or seconds, pre-ignition pressures are usually below 1000psi, 4000psi in galvanised steel tube would probably strip the threads and explode, or rupture.

[ferret_guy]

What pressure would you recommend? i went with galvanized steel because i wanted to do much higher pressures taking advantage of the scuba tank

[AircannonSweden]

I have 2 tanks(scuba tanks)that are rated to 1200 bars(17400 PSI)

You could maybe ask your local diving-shop/center or a firestation if they could refill the bottle!

[Fnord]

I would NOT recommend messing with a scuba tank right off the bat, unless you have suitable machining/engineering knowledge and a work shop to fit your skills. Standard steel pipe does not have a huge safety factor even in small diameters (I remember someone hyrdro-tested some 1/2" fittings and burst a tee at ~5000psi).

When you do decide you're ready, use a high-quality regulator and a high-flow pop off valve as a safety. Use Class-3000 (or higher) pipe and fittings only.

steel can with stand, thousands of psi, extreme high pressure. they why alot of hybrids are made of steel

Jsefcik
Stop giving people advice when you have no idea what you're talking about. I never had any problem with your occasional pointless or redundant questions, but here you're potentially endangering someone else by speaking out your ass.

[Gippeto]

http://www.engineeringtoolbox.com/wroug ... _1123.html

Would not recommend a safety factor of less than 5 with seamed (erw) pipe.

[ferret_guy]

I am confident in my machining/engineering knowledge and after talking to an industrial design engineer that I know he suggested the same things you did specifically pop off valve for safety. He could however not tell me if the threaded joints could hold the same as the working pressure of the pipe

[edit]
after looking at McMaster-Carr it appears that they suggest "threaded Schedule 160 extra-thick-wall galvanized steel" for 3,000psi applications and it is rated for "air, water, oil, natural gas, steam"
[/edit]

[jsefcik]

I would NOT recommend messing with a scuba tank right off the bat, unless you have suitable machining/engineering knowledge and a work shop to fit your skills. Standard steel pipe does not have a huge safety factor even in small diameters (I remember someone hyrdro-tested some 1/2" fittings and burst a tee at ~5000psi).

When you do decide you're ready, use a high-quality regulator and a high-flow pop off valve as a safety. Use Class-3000 (or higher) pipe and fittings only.

steel can with stand, thousands of psi, extreme high pressure. they why alot of hybrids are made of steel

Jsefcik
Stop giving people advice when you have no idea what you're talking about. I never had any problem with your occasional pointless or redundant questions, but here you're potentially endangering someone else by speaking out your ass.

i do have an idea on what im talking about if i didnt i wouldnt have said anything, you can kiss my dirt star

[MrCrowley]

i do have an idea on what im talking about if i didnt i wouldnt have said anything, you can kiss my dirt star

No you don't, jsefcik. I agree with Fnord on this one, you were talking out of your ass. If you did know what you were talking about, you sure as hell wouldn't have said what you posted.

[ferret_guy]

So I was looking at valves and I can't find any valves except ball valves that are rated for 3,000psi now I am not looking down on ball valves but they are not as awesome as something that can release much faster.

Any suggestions?

[Zeus]

Machine a piston valve, use a SCH160 tee to house it.

Jesse, steel can withstand into the millions of PSI, but that doesn't mean seamed mild steel can.

I wouldn't trust SCH40 steel under continuous pressure over 1000PSI, but for peak pressures I trust it far more. It's easier to see the ringing at weak spots, whereas high carbon steel just goes bang.

And MrC, you aren't American, so it's arse not a crossbred donkey.

[ferret_guy]

Could a piston valve switch 3000psi? if so what type to use?

[Crna Legija]

Could a piston valve switch 3000psi? if so what type to use?

A really strong custom made one, shouldn't be hard since you trust your machining.