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northof54
09-21-2006, 10:02 PM
anyone know?

thanx, mike

topct
09-21-2006, 11:20 PM
What have you found out?

dicks42000
09-21-2006, 11:53 PM
OK guys;
I'm assuming you mean the crimp-fitting system replacement for poly-butylene piping as used in low-budget plumbing systems.
Pex is a flexible piping available in roll or cut to "stick-length". Being a soft plastic it shouldn't display the lethal shrapnel problem on busting like PVC or CPVC rigid plastic piping will. (Unless it is used below freezing or what ever it's transition temperature is.)
The crimp fittings I use for liquid piping with this stuff are copper or brass, so that shouldn't cause a problem. The crimp joints seem to function well for years at city water supply pressures (120-160 psig.). Temperature wise it seems to work happily at 160 to 180 F. (typical hydronic system temps.)
The only problem I could see initially was with oil resistance if you got much carry-over from your compressor & air reciever. Could the oil attack the pipe ? I'll have to look that one up....
It's UV resistance isn't that good. Don't leave it outside in the sun for extended periods of time. This voids the warranty.....
I'd use copper myself though, or air hose. That's what I've done both at home shop & work shop.
Does that help?
Rick

Arcane
09-22-2006, 12:27 AM
The crimp joints seem to function well for years at city water supply pressures (120-160 psig.).

This seems a little high to me so I Googled "city water pressures". From what little I saw, 50 to 70 psi is the norm. BUT, one link produced these two stories about defective hot water heaters that blew up.
http://www.safteng.net/Accident%20Photos/Hot%20Water%20heater%20explosion.htm
http://www.theplumber.com/explodingwaterheater.html
There can be a great deal of energy involved when these things go blooie! I can't imagine what my house would look like if my w.h. blew... and I sure don`t ever want to find out!

dicks42000
09-22-2006, 06:51 AM
Google away....Currently the gauge on the city-side of my Pressure Reducing Valve reads 128 psig. (OK so I get gauges for nothing...) This is at night, (low water consumption) in a suburb of Vancouver....
Re....things going Kablooie....
Yep, things happen fast. Air is better than steam in that it generally isn't hot, so you don't get scalded or burned, but shrapnel is shrapnel. Gasses uner pressure contain energy, it wants to go somewhere. That's why you "hydro-test" boilers, vessels & piping...Note that gas piping systems are leak tested with a gas under pressure, though. (Usually for ease of leak detection & contamination issues.)
With a liquid-leak, the pressure & consequent stored strain energy in the vessel are relieved quickly, so less danger of Kablooie......
I still sort of like the idea of softer, flexible plastic for piping....and it goes together fast (why it's so popular with contractors.) Yet I still use copper for most work. Stuck in a rut traditionalist I guess.
As for the water heater failures, there are several modes I could forsee. Were these just the tank going 'Poosh" due to corrosion and dumping 40 gal. of water on the floor, were they gas explosions due to a leak or delayed ignition, or were they a firing/ heating explosion due to failure of the burner or element control to shut off and the failure of the relief valve to relieve...? (Long odds, but it happens.)
That's what I know....

Mcruff
09-22-2006, 06:04 PM
I work for a company that makes pex pipe at the other end of our facility. Raupex is the pipe, it is far superior to any of the other availabe pex pipes, its also made in a UV resistant form and air line grades. Our entire plant is plumbed in the stuff and has been for 10 years. We have had no failures, the stuff is self sealing to small punctures up to a point. Oil does not seem to attack it, at least not hydraulic oil as some of our molding machines have blown hydraulic lines and covered the pipe in it and then sit there for days before being properly cleaned with no ill effects. It is also technically freeze proof as far as ruptures from frozen water. Our air line grade is rated up to I think 400psi working pressure, Raupex is also warantied for some astronomical period of time. We have bunches of employees who have plumbed there houses in the stuff and several who use air systems in the garage shops with it.
Here is a link:
http://www.rehau-na.com/construction/heating...plumbing/radiant.heating/pex.piping.shtml

Fasttrack
09-22-2006, 10:21 PM
Yeah - i helped my brother-in-law lay down some of pex piping for a spigot outside the shop and it was some heavy-duty stuff rated at 400 psi...the other pex they had was only good to 160 and the wall was about half as thick as the 400psi stuff. I was wondering about using this for airline just the other day...from my posistion i can't see why it wouldn't work but thats just my $.02