Help! Are my Roadtrek's water lines compression or glued fittings?

[VTPete]

Hi All,

I need to put my fresh water tank back under my RV now that I've refurbished it. I want to replace the original water filter which use to connect in the middle with a small twist. (It's o-ring is hopelessly stretched out.) I'm replacing it with a new shurflo that screws in on the left and right sides and has a nice bottom filter that is much easier to clean out.

The problem I have is that I have no way of screwing the new filter between the water tank and the existing water line. If I screw it into the tank, I can't screw the water line in and vice-versa. Twist one side on and it untwists the other.

It begs the question: Are my grey-colored water lines connected via compression fittings or glued ends? I'm attaching a photo. In that photo, the threaded end connects to the out-flow of the water filter. If they're all glued, then I can't twist them to re-attach (unless I can find a kind of turn-buckle style threaded connector that has a reverse thread on one end.)

My brother said, "just cut those pipes and slip a hose between the ends with two hose clamps." Good idea, but too much of a hack to be "plan a".

Does anyone know how these fittings work? Does Home Depot sell compatible hardware? Help!

-Pete

[eric1514]

That gray pipe, I believe is polybutylene. It's no longer used. There are sharkbite fittings that can adapt that stuff to more common pex tubing.

I would assemble what I needed in pex and then adapt that to the existing old polybutylene with the proper sharkbite adaptors after cutting off those old threaded connectors.

[VTPete]

That sounds reasonable. Hopefully Home Depot has the necessary connectors. I'll first try to unscrew that to see what happens and then cut it off. When it stops raining.

I've never used sharkbite connectors, but I just read up on them and the way they snap in place is perfect in this case.
-Pete

[VTPete]

I just took a trip to Home Depot. While I'm not 100% sure I got the right parts, I did manage to find something with the label "polybutylene sharkbite adaptor". In the photo below, it's the piece on the right with the grey part sticking out. Seemed the right size, right name, etc.

And, they had a male pex shark bite to screw into the filter!

I picked up a 10 foot length of pex and I believe that's all I need to re-assemble!

Thanks for pointing me in the right direction, Eric!
-Pete

Originally Posted by eric1514

That gray pipe, I believe is polybutylene. It's no longer used. There are sharkbite fittings that can adapt that stuff to more common pex tubing.

I would assemble what I needed in pex and then adapt that to the existing old polybutylene with the proper sharkbite adaptors after cutting off those old threaded connectors.

[eric1514]

That’s it.

[VTPete]

Unfortunately the polybutylene connector is the wrong size. The polybutylene tubing in my RoadTrek is smaller than whatever standard size that SharkBite connector was expecting. I should have cut the existing tubing and brought it with me.

A subsequent visit with the actual tubing lead to me picking up a Sharkbite connector for "3/8 inch tubing". I believe it's a perfect fit and will be doing final connecting tonight if it's not raining...

By the way, the box tubing supports I made for the water tank are SO MUCH better than the thin U-Beams originally installed. The added 10 pounds of the new supports shouldn't cause the hangers to snap and, yay, no more bowing under the RV!