Plumbing connections using barbed fittings

[Bob Miller]

Originally Posted by Johnny M

I agree about the low cost of using a clamp, but Bob, my decision on not using clamps was based on the link you provided which stated in the document:

"There is also a downside to clamps. If installed incorrectly, clamps can actually induce leaks and failures. If a tie ‐ type clamp is cinched too tightly on low durometer, or soft tubing the clamp can lift the tubing away from the fitting. Securing a clamp over the portion of tubing that is stretched over a barb can have the same effect degrade the seal enough to cause leaks."



My connections have multiple barbs, so my thought was to test for leaks then add clamps if needed.

Maybe I should consider some kind of sealant with the fitting?

One has to hope that the clamp installation will be done "correctly" as would all of the other aspects of the installation. All bets are off if one has to always fear that something will be done incorrectly.

The whole world of RV's is running with hoses clamped into place with correct sized & tightened clamps. But I am sure that more than a few have had unclamped hoses pop-off after anything from hours to years of use.

BTW: Any sealant that does not harden would have to be adhesive compatible with both materials, the hose and the fitting, sealants that don't harden would tend to provide a lubricant to help the hose slip off with time.

[frank_a]

Clamps must be sized to the hose. Parkliner used too big a clamp on my shower hose - it leaked, as the clamp was tightened into an odd shape. Correct clamps (I always use two on barbed connections) did the trick.

Frank

[stevebaz]

This is what I used inside my 13 foot Scamp. This tube is rated at 250 psi. Uses barb fittings and hose clamps.

Sioux Chief 3/8 in. x 10 ft. Vinyl Braided Tubing-SBVKG10 - The Home Depot

[frank_a]

Originally Posted by stevebaz

This is what I used inside my 13 foot Scamp. This tube is rated at 250 psi. Uses barb fittings and hose clamps.

Sioux Chief 3/8 in. x 10 ft. Vinyl Braided Tubing-SBVKG10 - The Home Depot

That is what is used in my Parkliner as well. Heavy duty stuff!

Frank

[Steve L.]

My thoughts are that the suitability of hose clamps in part depends on the compressibility of the hose’s wall. Rubber and vinyl hoses being pretty good for this while the harder PEX tubing isn’t. Tightening down on PEX is more likely to deform it into a non-circular shape than it is to compress it while staying round. It might be possible to jam a barbed fitting into PEX and count on friction to hold it in place but it’s not something I’d recommend (I’m still in charge of what I recommend, right?). Even if the PEX ID is close to the barb’s OD I’m not feeling warm and fuzzy about the connection.

[The Minimalist]

"BTW: Any sealant that does not harden would have to be adhesive compatible with both materials, the hose and the fitting, sealants that don't harden would tend to provide a lubricant to help the hose slip off with time"

And OK for potable water on fresh water connections.

[Bob Miller]

Originally Posted by Steve L.

My thoughts are that the suitability of hose clamps in part depends on the compressibility of the hose’s wall. Rubber and vinyl hoses being pretty good for this while the harder PEX tubing isn’t. Tightening down on PEX is more likely to deform it into a non-circular shape than it is to compress it while staying round. It might be possible to jam a barbed fitting into PEX and count on friction to hold it in place but it’s not something I’d recommend (I’m still in charge of what I recommend, right?). Even if the PEX ID is close to the barb’s OD I’m not feeling warm and fuzzy about the connection.

PEX tubing and fittings are not designed for the use of hose clamp in any RV application.

[DeniseinMaine]

I haven't redone the plumbing in my camper..yet, but it's on my agenda. However I did remove about 30 to 40 feet of Hot and Cold copper water line in the upstairs of my house. The water lines go from an upstairs bathroom to my stained glass shop via bedroom eaves and a closet. I used Sharkbite fittings and PEX pipe and have not had any problems with it, zero. I drain them when it gets cold up here so that they won't freeze. I've been told that the PEX is a lot more tolerant of the freezing than copper is, but I'd just as soon not push it. But I've had no leaks..in fact, getting the Sharkbites and the PEX to separate requires a little U shaped plastic tool (that is purchased separately according to the size of the PEX) and it takes a little doing (for me) to separate them. Works great, I plan on using the PEX and Sharkbites to reno my camper water lines.