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Pressure Rated

Posted: Mon Aug 11, 2008 5:22 pm
by DrowningTrout
I made an order for some PVC fittings, but it did not say on the site if it was DWV, so I wanted to double check and asked if they were rated to atleast 150 PSI.

I got back an interesting reply.
Thank you for your order.

In the notes of your order, you asked if the PVC fittings you were
ordering were rated at-least at 150 PSI.

They are, but only for liquid, not solids or gas.

Will these work for your application?

Since we are unsure if these are what you need, we will be holding
your order aside until we hear back from you with how you would like
to proceed with your order.
Only for liquids?
I always thought PSI ratings were that, no matter what was exerting the force (Gas, Liquid same PSI).

BTW: How does solids have a PSI?

(Then again it was a woman who answered ) :lol: [/quote]

Posted: Mon Aug 11, 2008 5:35 pm
by TurboSuper
Uhhh...well, PVC pipe as a rule is said not to be used for anything but liquids(or solids, I suppose).

Liquid pressure has alot less energy in it than gas pressure, so if the pipe fails, it won't "grenade" with a liquid like it will with a gas. But pressure is pressure, and pipe ratings are pipe ratings. Just ask if it meets the nsf-pw specification, because nsf-pw sch 40 will be well over 150 PSI anyhow.

That being said, we haven't heeded the manufacturers warning until now, and I doubt we're gonna start :D

Posted: Mon Aug 11, 2008 5:36 pm
by SpudFarm
it says "only liquid and solids" because that does not store energy.

you are 100% fine, it is the same thing untill you drop it :lol:

Posted: Mon Aug 11, 2008 5:38 pm
by jrrdw
Solids being dryed powdered ingredents I think. I also think that will be the genral response from any PVC manufacture.

Posted: Mon Aug 11, 2008 5:39 pm
by Hotwired
There is a pressure rating of all rated objects. Then what it is rated to be used for.

PVC pipe is rated at that pressure for liquids.

PVC has unfavourable characteristics when it fails (smashes into bits basically) so carrying high energy gases is not it's ideal use.

That doesn't mean it can't hold gas at that pressure, of course it can, it just isn't an ideal material to be using.

Piping rated for liquid and gas use under pressure are either much stronger, much tougher or both. Stuff that either has a burst rating so high it's unlikely to do so or that splits instead of shattering when it gives way.


Take so long posting, three others do it before me :lol:

Posted: Tue Aug 12, 2008 2:59 pm
by psycix
They always say its not for gas, since a blowing pvc pipe filled with gas does way more damage then one filled with water.

PVC is made for holding air just as much as it is made for spudgunning.
However, PVC does both jobs pretty well.