The fail pressure of a Schrader valve?

[Mitchza89]

Howdy gunners,

I'm thinking about using a schrader valve valve as a check valve for my high pressure pump. I plan on going up to 600+psi. How much do ya reckon it could take before it fails?

I'm also curious to know at what pressure a copper compression fitting fails...

Cheers .

[Gippeto]

Do you have a picture of the one you want to use?

If it's similar to the ones I have, I'll rig one on the dead weight tester and "find it's pressure limit".

How are you going to attach it? ie. epoxy, threads, or ?

You know that I tested a schrader before right? The cracking pressure on it was 70psi.

Can't help you with the compression fitting, sorry.

[Gippeto]

I ran the pressure test on the schrader valve today.

I used a dead weight tester with a max pressure of 300 Bar.

The schrader was checked before the test for damage and function.

The test started at 7000Kpa and pressure was increased by 1000Kpa every 5 minutes until I ran out of weights.

There were no signs of leakage or other damage visible.

After the test, the schrader was disassembled and checked for damage to the sealing face (expected to see some), none was visible.

The schrader was re-assembled and tested for function. It performed as new.

How it would stand up to cycling pressure as in a pump is anyones guess, but I have to admit they are tougher than I gave them credit for being.

[Mitchza89]

Jesus... That's really impressive! Thanks alot for that mate. I really appreciate it. I'll have to try and find myself a schrader valve that's threaded!

[jrrdw]

Jesus... That's really impressive! Thanks alot for that mate. I really appreciate it. I'll have to try and find myself a schrader valve that's threaded!

www.bcarms.com has them. See how easy that was.

[Fnord]

I've used one at 900 psi as a check valve. Try and get one you can take the spring out of (they open at about 100 psi w/ the spring, but you'll notice the difference when you have to pump up a high pressure chamber).

[POLAND_SPUD]

@ gippeto hmmm I am wondering.... could you test some malleable iron fittings ? I know that won't tell us much (and there is a risk that it may wrongly suggest some people that the fittings are stronger than they really are)

I fell a bit unsafe using them on my pump and gun (mostly 1/2")... I know that 400 - 500 psi isn't that much but I am curious at what pressure they fail (is it 1000psi or 2000 psi? what kind of fittings fails first ? elbows/Ts?)

[Gippeto]

Maybe...they are pretty cheap, and the information could be of use.

Do you use more plated parts or straight black iron?

I know I can "fracture" 3/8" 316ss compression fittings with the big tester.

Give me a day or two to think about how to burst them safely.

Maybe in a tub of water to dissipate the energy of the spray?

Any other ideas?

[jrrdw]

Some how place wire mesh over the tub of water??? Test in balistics gel??? 2 off the top of my head.

[POLAND_SPUD]

@Gippeto

Do you use more plated parts or straight black iron?

I am not sure if I understand 'plated' in the right way but I use galvanized ones

Maybe in a tub of water to dissipate the energy of the spray?

yeah I think that will be enough..

THX

[Kobl]

I would love to know the results as I really want to know how far I can push my guns that have iron fittings on them.

[SpudFarm]

damn that is awesome gippeto!

i love all your work!

[Gippeto]

I've been giving this some thought, and I think that while the tub of water idea has merit, it means using a hydraulic hose to connect things.

The hose will expand and "store" some amount of energy, which will have to be dissipated.

If I were to simply attach the fittings to the tester, the only "stored" energy would be in the volume of fluid actually raising the piston and weights.

I am thinking about resting a 2" cap and close nipple over the test fitting and then a couple of rags over that. I would tie the rags underneath to close things off. The 2" stuff should direct any shrapnel or high pressure spray downward and the rags should slow the "stuff" down.

Comments?

[Mr.Sandman]

yeah thanks for la informacion senor

[Gippeto]

Testing of the 1/2" galvanized and black iron fittings is complete.


Please keep in mind that the results are valid ONLY for the fittings that I tested.

***MY FITTINGS ARE NOT YOUR FITTINGS***


If you hurt/maim or otherwise kill yourself or your friends it's your own damn fault. Got it?












The results were very surprising too.

The upper pressure limit was set at 70000kpa. If anyone gets close to this, they will not be using cast iron fittings. (And a fitting "blowing" up at 15000psi is not something I wish to be within 2 feet of again!)

Testing started at 300 bar and the increments for the test were 100 bar.

The pressure was applied, let off, another weight was added and the pressure was re-applied. Repeat until 70000kpa or burst. 8)

Galvanized fittings;

1/2" 90degree elbow withstood 70000kpa (~10152psi)

1/2" tee burst at approx 60000kpa (~8702psi)

1/2" coupler withstood 70000kpa


Black iron fittings;

1/2" 90degree elbow withstood 70000kpa

1/2" tee burst at approx 60000kpa

1/2" coupler withstood 70000kpa

I have pictures of the fittings which I will upload later.