Is it OK to use a plastic valve designed for house water (which here reaches to 85 psi) in equipment where the water can reach 200 psi (at 95*C)?Lambda - 2-6-2005 at 02:43
Quote:
Originally posted by Quince
Is it OK to use a plastic valve designed for house water (which here reaches to 85 psi) in equipment where the water can reach 200 psi (at 95*C)?
I personly would aim at gas-valve usage. They are however, often made of brass (copper/zink alloy). This could be a reactive problem though. But the
seals are excellent. An additional advantage is the fast open and close, often with one swing on the leaver. The mainwatersupply tap of houses,
sometimes allso use this system.
In aquarium and fishery stores they can be bought in a stainless steal version.
You are talking about pressures in the region of about 14 bar, and house hold watersupply pressures usually range in the 2-5 bar region. Even at room
temperature 14 bar would be overcooking the bottom of the stew pot, and if you are using agressive chemicals: get a good medical insurance, and ask
the ambulance to wait outside.
Overstressing plastic valves at 95 deg. C is asking for an accident to happen.
Quote:
Suicide is painless...........M.A.S.H.
[Edited on 3-6-2005 by Lambda]Twospoons - 2-6-2005 at 14:10
Usually the valve will have a pressure rating marked on it somewhere. Depending on the valve design, it may not operate properly at pressures above
those it was designed for.Quince - 2-6-2005 at 15:12
I don't plan to open/close while the pressure is high. I just don't want it exploding or something. Pressure will usually go to 9 atm (max
14), only while closed. As long as it doesn't leak much while it's closed I don't mind. But given Lambda's warning, I'll
put a case around it in case it blows up.
What's the recommended way to seal teflon tubing to the joint? I don't think silicone will stand the hot water.evil_lurker - 2-6-2005 at 15:29
Having experience with PVC valves, I'm gonna flat out tell you that regular PVC will NOT hold up to temps/pressures that high, and it would be
pushing it with CPVC.
Get a stainless ball valve with teflon seals if you have to have high pressure/tempurature/corrosion/reactivity resistance. I would recommend using
stainless steel line as well for thos conditions, no hose.
If reactivity is not going to be an issue, then use brass ball valves with braided rubber hose.
