Dura-Pex vs copper pipe

[kmdigital]

In my case the hot water made it 70' to the basement thru insulated pipe & was still hot enough to lift the relief. I can't imagine that anyone is going solar with uninsulated pipes!!! Fortunately my relief is piped to a 5 gallon jug so I didn't loose any antifreeze but lost system pressure & had to pump it all back in after the collectors cooled down. Don't know if it would affect PEX but it should be considered. MikeD74T

The question I have is did the heat open the relief valve, or did the pressure open it? Hot water expands quite a bit as it heats up, and if it starts boiling the pressure goes up very quickly. Depending on your antifreeze concentration, it would need to get to about 250-260 degrees to boil, but i suppose it could happen on a roof on a hot day.

If your system has an expansion tank that should have taken care of any ordinary expansion as the water heated up, but if it got hot enough to boil the water an expansion tank would definitely not have been enough to prevent the relief valve from opening. When water turns to steam it expands app 1,680 times, so it takes up a LOT more room than before.

 

[MikeD74T]

The question I have is did the heat open the relief valve, or did the pressure open it? Hot water expands quite a bit as it heats up, and if it starts boiling the pressure goes up very quickly. Depending on your antifreeze concentration, it would need to get to about 250-260 degrees to boil, but i suppose it could happen on a roof on a hot day.

If your system has an expansion tank that should have taken care of any ordinary expansion as the water heated up, but if it got hot enough to boil the water an expansion tank would definitely not have been enough to prevent the relief valve from opening. When water turns to steam it expands app 1,680 times, so it takes up a LOT more room than before.

It's a Watts relief valve with settings of 150psi /210F. There is an expansion tank included in the system. Since water at 320F only generates about 80psi steam pressure I'm sure it was the thermal element that opened it. MikeD74t

 

[kmdigital]

It's a Watts relief valve with settings of 150psi /210F. There is an expansion tank included in the system. Since water at 320F only generates about 80psi steam pressure I'm sure it was the thermal element that opened it. MikeD74t

Yeh, you're right. I didn't check the tables, and I was thinking the pressure goes up faster than that.

 

[SPIKER]

Respectfully,
PDR

Patrick D. Reed
Northeast Regional Sales Manager
UPONOR Inc. (formerly WIRSBO)
PO Bx 296
Selkirk, NY 12158-0296
Office: 518-767-3370
Fax: 952-997-1712
e-mail: PATRICK.REED@uponor-usa.com

Patrick: I'm getting ready to start install on a radiant heat system, using outdoor wood burner 1st floor radiant concrete, (I have PEX-al-Pex 1/2" & 3/4" with plenty of fittings) but I'm looking for a good base board system for the 2nd floor. perferable something with it's own thermostat and a blower which only needs 120 ac and 1/2" pex in/out. Does the new company carry anything like this?

thanks

Mark M

 

[neilly2]

I just finished our new house and had PEX installed for both water supply and for radiant floor. Pics of both attached. We have 2 distribution blocks for the plumbing -- a small one right off the well for the kitchen sink cold and the outside faucets. The second, main distribution block is downstream from the water softener.

PROS--

Quick install -- you set up a pull like its electrical wire (but see CONS)
No water sound through pipes or pipes creaking--its silent
Can shut off a single fixture in the basement like a breaker panel
Cheaper than copper
Water tastes fine and I've never heard of a taste issue
You can flush the toilet while your wife's in the shower and she'll never know
Minimal fittings equal less hydraulic loss equals better flow at the faucet.

CONS--
I had a plumber do it, so now when I want to add on I have to buy the crimp tools and parts.
The tubing is pretty stiff and requires a large bending radius (12-16") so you need to watch for kinking and plan concealment.
Also the tubing has a natural curve from the reel you have to work with.
You go insane hoping the drywallers don't put a screw through it -- we kept pressure on the lines through sheetrock, so we would know.

Overall to end user its a better product, and I would use it again.

 

[neilly2]

Not the best picture for it, but you can see how it transitions to copper to get through the wall for fixture connetion. We bought these pre made with nail plates.

 

[dtd24]

I used pex in my house as well. They actually just came out with a new crimp tool, that is pretty cheap. Check your local plumbing supply house. Does all sizes of pipe, it's the collar that is different. Looks like the screw on pipe connectors, but instead of a screw it gets crimped. Works great!!!!!

 

[Lazy]

Hi
what size are the red and blue tubing you used for the hot and cold water supply? Looks a small in the pics.

Charlie

 

[river rat]

After seeing a new house plumbed with PEX, I've decided to never use anything else again! Really neat to work with. My question - I got some from Lowe's for a small project, and chose the "slip-in" fittings which don't require a crimping tool. Have I made a bad choice?It sure looked like an easy installation, but hasn't been done yet - if I should go back and get the crimp style fittings, I can still do so. Any suggestions?

 

[KEG]

The PEX piping installed in my project was all half inch. It is very similar in wall thickness to regular copper pipe. The main feed was brought in as a 1" line to a header unit, similar to the Manablck posted earlier but in my case it was a copper header that had several 1/2" stubs. Individual feeds went from the header to the kitchen, bathroom, shower, etc. etc. and each was a "homerun" meaning each line came from the header and was not tapped from other 1/2" lines.

Now I haven't had a chance to see, operate or hear this in operation, but it looks pretty slick. Although I'm a fan of copper, market conditions, the cost of labor, and an optimistic trust in new technology makes this a candidate for continued use in other projects.

KEG