PEX fitting types: Which are best?

[TheHubbardBus]

Forget about price, availability, or tools required. All other issues aside, what would be the absolute best type of fittings (expansion, compression, push-to-fit, etc) to use with PEX in RV plumbing applications? Which would produce the highest level of reliability & longevity, and the lowest chance of leaks or failure?

[o1marc]

I tried to use only the brass barb fittings. Not sure if I used any of the plastic/vinyl ones or not. Bought in quantity packs they aren't that much more expensive for the piece of mind. The only difference in tool is what crimp fitting you use. I use the pinch clamps and am okay with them. I think no matter which way you go, they will work. My only concern would be plastic ones that have water in them that might freeze.

[roach711]

So far, the "sharkbite" fittings appear to have good reliability but for a vehicle that is likely to have it's water lines frozen at some point I'd go with the brass crimp fittings. You can buy an inexpensive crimp tool and the crimp fittings are way cheaper than the push-on fittings.

[o1marc]

There are 2 types of crimp rings, solid and the silver crimp style. The tool for the silver ring is much cheaper than than the solid ring crimp tool. Both will exceed requirements.

[roach711]

I use the solid type rings. They just look less likely to fail. I bought this inexpensive crimp tool:

https://www.pexuniverse.com/sioux-ch...ool-305-100pk1


No matter which way you go, make your connections somewhere that you can get at them later if repair is needed.

[bus-bro]

I don't know. I use the barbed brass fittings with the compressed ring because they're cheaper, but I use Sharkbites if I don't want to restrict the water flow through the fittings. Buy a proper tubing cutter whatever you do, and a good crimper for whatever ring fittings you use.

[cadillackid]

the fittings on the top that marc showed are the same ones used on A/C lines like the Burgaflex type. and they dont leak even under high pressure of A/C refrigerant..


-Christopher

[TheHubbardBus]

Muchisimas gracias mis amigos! Crimp it is.

[JDOnTheGo]

I don't have any statistics to say which approach is the best given the stated criteria. That said, I used the solid ring crimp style PEX (and mostly brass connectors). I am happy with them after nearly three years of full time use (including a few freezes). There are often a few places where crimping is mighty difficult or impossible. In those places, I used a press-on style and they seem to work just fine as well.

[NOLA]

Either crimping ring works great when properly used. Watch a few YouTube videos and keep the crimp ring where it should be on the fitting.
From my experience with well water in the southern U.S., I find the brass develops needle-sized holes after 8-10 years. My brother is having to replace all his down stairs brass connections after 4 started to leak due to pin hole corrosion. My concern with the plastic is a HARD freeze and cracking. It is not a big issue along the coast. I live in New Orleans and will use plastic fittings when building my house. Usually the Pex expands & may leak by a fitting when it freezes, but it tends to contract & reseal after it warms.

[Mudhutwarrior]

Propex are best for mobile applications but the tool to install them is expensive. They actually bind better over time and accept some movement.



With any pex fitting you should have a heat gun and warm the connection before clamping especially in mobile applications if your in a cool enviroment and use quality pex pipe Pex A.

[makaufmann]

Reading quite a bit about pex and currently using 1/2" pex with ring crimp connectors. From everyone here, what is your water flow/pressure like? Any issues? How many 90 degree connectors and T fittings did you use on your water line runs? I'm worried about flow rate dropping due to all of the fittings used in my installation. Can't find a decent pex flow rate calculator anywhere?? TIA

[TheArgobus]

I also was worried about flow being affected by all the fittings/angles (I'm using crimp style Sharkbite 1/2" fittings). So I used gradual curves instead of 90 degree fittings where i could (mainly under the floor). The PEX does bend okay, I'd say probably about a 8" radius turn, at the expense of having more tubing. But I think that's okay.



I did have to put a 90 degree elbow in where I had one of these "gradual curves" because it was pulling on my water heater. The pressure isn't that great, but whatever, it's a skoolie.