Pressure water plumbing

[Russell]

Steve, that grey stuff is polybutylene, its generally very good, but does stiffen with age and get brittle (which is the problem I am having). Getting your hands on the stuff these days is next to impossible though due to class action lawsuits when the stuff was used in houses (having to do with crimp fittings that often broke and did major water damage, not the compression style fittings CD used), even though good compression fittings were available, the class action suits spelled doom for polybutylene and thus PEX looks the only real alternative today.

[J Stevenson]

Last year I replaced the hot water heater and in the process installed PEX lines in a portion of the pressure water system. I first tried to use use the Sharkbite fitting and found them unforgiving, not reusable and physically hard to install in limited spaces. I turned to the Sea Tech fittings (a WATTS company) and have been very pleased with the results. Aside from being reusable I especially like that they can be rotated on the PEX after installation which allows reorientation of the fittings as necessary for proper alignment.

[Klem]

We converted one of the commercial boats that I worked on to PEX that had a number of passenger cabins so it was a similar style installation just much bigger with a ton more connections. The tool is expensive but it is very good, can you try to borrow or rent one? I don't think that we had a single leak over several years. Given the complexity of the water system, I can't guarantee that all the lines were properly winterized but there were never any problems there.

There are two things that I think should be kept in mind with PEX. First, it is really stiff and the bend radius is quite large so it is not great in confined spaces. Second, I find it more difficult to work on that standard hoses and barbs. On a small sailboat, carrying the tool takes up a lot of room and getting the old hose off the fittings is harder.

If it were me, I would go hose and hose barbs in a simple installation and PEX on more complex ones.