black polybutylene pipe; is that what this is?

Sol_Brother

All the polybutylene pipe I have seen is gray, and I have read here that Vanguard made red O2-barrier variety, but this black pipe has the type of fittings I have seen only on polybutylene. (I am referring to the gray compression coupling and the InFloor copper compression ones.) The situation is a contractor drilled a hole in the floor and hit a radiant pipe in this old system. He sent me this photo but I have not been able to get to the site to see any markings on the pipe.

If you have seen this before and can id it for me, please chime in. We would like to be prepared to put in a coupling when they chip up the concrete to expose it, but I have no idea if a standard Qest coupling will fit this.

hot_rod

that look like basic PP pipe, we call it well pipe or lawn sprinkler pipe. IFTHE OD is the same as PB, which was CTS copper tube size, then a compression fitting would work.

I don’t recall Infloor selling that black tube. No names or listings?

The tan colored Grundfos in the background suggests early 1990s?

An internal barbed fitting and stainless clamps is a common fitting for PP tube.

HomerJSmith

From the manifold it looks like Infloor which was produced in the early 90's. They used PB in their sys which was a non barrier tubing. I would splice it like Pex B. It was an odd size tubing. I would use a Sharkbite brass coupling with stainless pinch clamps. Protect the splice when you pour the concrete.

Sol_Brother

Thanks for the notes. Yes, I'd say 90's vintage system. I have seen a few InFloor systems before, but all with gray Qest polybutylene.

One of our techs inspected it today and what he reported is surprising:

• no sign of manufacturer or other marking on the black pipe. The gray plastic compression fitting is labeled "Qest" and has a product number referring to a 3/8" fitting he is trying to trace at Grainger.
• the pipe is smaller than I took it to be. He says his 1/2" PEX crimpers slid easily around it even when tightened, so he gauges the tube's OD to be a bit smaller than 1/2" PEX.
• but the oddest part is, with no fluid pressure on it, he can press his thumb on it and depress the side of the pipe. He is familiar with Onix and says it does not feel like that (plus real Onix would have been labeled somewhere in the quite a few feet that are visible.) So, unless this pipe is severely eroded (a real possibility given its age) it is something more flexible than any plastic I have dealt with. More flexible than commodity black well pipe Hot Rod mentioned, although perhaps irrigation pipe might be thinner-walled(?). But knowing the company that installed this, I don't think they would have taken that route. But then I have not seen it first-hand.

But here is a tidbit I had not shared in the posting: the reason a hole was drilled into this pipe was in the process of installing a safe. So when this repair is done and tested, even if we protect and pack sand or fluff around the fitting, there will be enough concrete poured over it to secure their anchor, then tile, then a safe. So I don't think we are ever seeing this one again. We are praying there are valved manifolds at each end of the floor loops so we can shut this one off without cutting into any more pipe.

All that leaves me queasy about any compression or barb and clamp fitting. Less so about crimps, so I might try a combination of both stainless steel pinch and copper crimp on either a 3/8" PEX or Onix coupling.

mattmia2

Is there a system out there that expands a pex ring but not the pipe and uses it sort of like a crimp ring or hose clamp?

hot_rod

There were a number of odd ball one off radiant tubes made over the years. I worked on a system in a greenhouse that had a tube like you describe. It was a packaged hydroponic system from a company called CropKing.

Another odd ball was a carwash company that offered a ThawMaster package that used a black plastic tube, RayPak copper boiler. That was more of a PP tube.

MPH multi purpose hose is what you buy as entry level hose at hose dealers, similar to automotive heater hose. It doesn't always have listing data printed on it if it is an import, pricepoint, knock off hose.

I'd go to an auto parts or hose supply store and buy some brass barbed couplings, stainless hose clamps, a piece of large heat shrink tube to melt over the splice and call it good.

If you can depress the tube wall, a barbed insert fitting should hold the pressures you are dealing with.

Barbed inserts work best if the tube is out of round also.

Sol_Brother

I meant to say in my last posting: we hope we will be able to shut off this one loop in case the repair fails at some point in the future. Our goal is to have it actually working.