PEX piping question for plumbers

dougrainer wrote:

I don't think there are different grades of PEX. This is the FIRST time I have seen PEX split from freezing. MY crimp tool took a lot of force to crimp the ring that I replaced on both. Doug

All PEX is the same basic material and has to meet the same ASTM/CSA/NSF standard. It's manufactured using 3 different processes - designated PEX-a, PEX-b or PEX-c and each version has different characteristics as explained here.
PEX-a has the best properties and it can be severely kinked and damaged and brought back to original shape by heating with a heat gun. PEX-a can expand to 3 times it's original dia. and will return to its original size which makes it freeze resistant. I *think* Pex-a is what's most widely sold and all I've run across. PEX made by Zurn is Pex-b with specs here.. PEX-a costs more.

The hotter the operating temp., the lower the pressure rating PEX has - standard rating 100 psi @ 180F & 160 psi @ 73F (printed on exterior).

PEX should not be exposed to direct or indirect UV. Different brands/types can have different exposure limits. PEX exposed to fluorescent lighting indoors can be damaged from the UV rays. From experience, plumbing wholesalers will not take back PEX due to possible UV damage. Now that someone mentioned it, our low point drain PEX and valves hang down at the very rear of our TT and quite exposed to UV ray - may be a good idea to do something about them. A removable plastic sleeve of some sort might all that's needed.

According to the Plastics Pipe Institute, PEX is freeze resistant. It is not freeze proof though. Can't find any info. on typical min. temps. before damage occurs. UV damage will increase the chance of freeze damage.

Plastic PEX fittings used in RVs are made from a polysulfone/polyphenylsulfone blended polymer and have a pressure rating of 100 psi @ 180 deg. F and 160 psi @ 73 deg. F. Like PEX, these fittings need be protected from UV. Uponor lists 30 days as max. exposure time. Temp. operating range from -50C (-58F) up to 200C. Providing not exposed to UV, should not fail under low temps in most cases except maybe somewhere like Alaska. I can't see any reason to change these out for brass.

A PEX crimper will require the same force to crimp a ring on 100 or 160 psi. Try crimping a ring without any pipe. Standard crimper can be difficult inside RV cabinetry and there is a pocket crimper for tight spaces that uses vise grip pliers. I may get one in case if needed for an emergency on the road repair.

Not a plummer by trade, but google is my friend...

NanciL wrote:

nomad297 wrote:

RJsfishin wrote:
Your story is sure different than plummers I've talked to
In fact there are those that will guarantee pex to never split from freezing.

Well, the OP asked for advice from plumbers. Not from people who once spoke with a couple plumbers. I am a plumber and I know what I'm talking about. Don't try to tell me my "story" doesn't sit well with you because of something you heard. My life is and has been plumbing for over three decades.

Bruce

Thanks,
And I am putting stock in your reply.

It sure would be nice if people would read what is asked and not respond if they are not qualified, but it seems there are a lot of people who feel they are experts when in fact they are not.

Jack L

Not only is he a plumber by day, but a French model by night.

This is the internet, you can't expect more then what it is. Take it all in, then do your own due diligence and make the call.

nomad297 wrote:

RJsfishin wrote:
Your story is sure different than plummers I've talked to
In fact there are those that will guarantee pex to never split from freezing.

Well, the OP asked for advice from plumbers. Not from people who once spoke with a couple plumbers. I am a plumber and I know what I'm talking about. Don't try to tell me my "story" doesn't sit well with you because of something you heard. My life is and has been plumbing for over three decades.

Bruce

In other words, don't take plumbing advice from someone who can't spell plumber. :)

nomad297 wrote:

RJsfishin wrote:
Your story is sure different than plummers I've talked to
In fact there are those that will guarantee pex to never split from freezing.

Well, the OP asked for advice from plumbers. Not from people who once spoke with a couple plumbers. I am a plumber and I know what I'm talking about. Don't try to tell me my "story" doesn't sit well with you because of something you heard. My life is and has been plumbing for over three decades.

Bruce

Well, can't 'wishing' make it so??

nomad297 wrote:

RJsfishin wrote:
Your story is sure different than plummers I've talked to
In fact there are those that will guarantee pex to never split from freezing.

Well, the OP asked for advice from plumbers. Not from people who once spoke with a couple plumbers. I am a plumber and I know what I'm talking about. Don't try to tell me my "story" doesn't sit well with you because of something you heard. My life is and has been plumbing for over three decades.

Bruce

Thanks,
And I am putting stock in your reply.

It sure would be nice if people would read what is asked and not respond if they are not qualified, but it seems there are a lot of people who feel they are experts when in fact they are not.

Jack L

RJsfishin wrote:
Your story is sure different than plummers I've talked to
In fact there are those that will guarantee pex to never split from freezing.

Well, the OP asked for advice from plumbers. Not from people who once spoke with a couple plumbers. I am a plumber and I know what I'm talking about. Don't try to tell me my "story" doesn't sit well with you because of something you heard. My life is and has been plumbing for over three decades.

Bruce

John&Joey wrote:

dougrainer wrote:

John&Joey wrote:

Chris Bryant wrote:
..I have found PEX is not at all good with UV...

PEX is big up here in the frozen Tundra. Easy to work with, cheaper then copper, and takes one heck of a freeze. PEX comes out and says it is not UV stable. If you have to have it outside then at least cover it with paint.

The LOWEST temp here in North Texas this past winter was around 10 degrees for just a few days and that is what split the PEX. We had 2 Tiffin motorhomes come in this past week and both had the SAME Pex split. It was a 3 inch section (Cold) that connects the feed Pex to a copper manifold split that the other cold water pex lines feed off. The REST of the Pex did not freeze and split, even in the water bay. The customers did not blow their units out and this pipe was vertical under a rear lavy area sink which allowed the residual water to stay in the line and expand. Doug

I'm starting to think there are different grades of PEX. When I crimp a ring on house type PEX I need to squeeze pretty hard with both hands. When I squeezed one on the RV line this winter I thought I goofed since it squeezed so easy I thought my crimper didn't grip. Thinking RV's use the cheap stuff which might not take a freeze as well as the S&B stuff.

I don't think there are different grades of PEX. This is the FIRST time I have seen PEX split from freezing. MY crimp tool took a lot of force to crimp the ring that I replaced on both. Doug

dougrainer wrote:

John&Joey wrote:

Chris Bryant wrote:
..I have found PEX is not at all good with UV...

PEX is big up here in the frozen Tundra. Easy to work with, cheaper then copper, and takes one heck of a freeze. PEX comes out and says it is not UV stable. If you have to have it outside then at least cover it with paint.

The LOWEST temp here in North Texas this past winter was around 10 degrees for just a few days and that is what split the PEX. We had 2 Tiffin motorhomes come in this past week and both had the SAME Pex split. It was a 3 inch section (Cold) that connects the feed Pex to a copper manifold split that the other cold water pex lines feed off. The REST of the Pex did not freeze and split, even in the water bay. The customers did not blow their units out and this pipe was vertical under a rear lavy area sink which allowed the residual water to stay in the line and expand. Doug

I'm starting to think there are different grades of PEX. When I crimp a ring on house type PEX I need to squeeze pretty hard with both hands. When I squeezed one on the RV line this winter I thought I goofed since it squeezed so easy I thought my crimper didn't grip. Thinking RV's use the cheap stuff which might not take a freeze as well as the S&B stuff.

John&Joey wrote:

Chris Bryant wrote:
..I have found PEX is not at all good with UV...

PEX is big up here in the frozen Tundra. Easy to work with, cheaper then copper, and takes one heck of a freeze. PEX comes out and says it is not UV stable. If you have to have it outside then at least cover it with paint.

The LOWEST temp here in North Texas this past winter was around 10 degrees for just a few days and that is what split the PEX. We had 2 Tiffin motorhomes come in this past week and both had the SAME Pex split. It was a 3 inch section (Cold) that connects the feed Pex to a copper manifold split that the other cold water pex lines feed off. The REST of the Pex did not freeze and split, even in the water bay. The customers did not blow their units out and this pipe was vertical under a rear lavy area sink which allowed the residual water to stay in the line and expand. Doug

mrgreetis wrote:
So, regarding the UV stability, if we have PEX low point drains or any under carriage lines, should they be protected somehow?

ONLY if that Pex is exposed to sunlight. UV will not bounce off the ground and harm the Pex:B So, no. Doug