My house’s plumbing was redone a few years ago using Uponor PEX lines and black (ABS?) plastic fittings with stainless clamp rings. I now want to add a tee for a hose bib. My local HD just has Apollo lines and brass fittings.
My question: is it generally safe to mix brands and fitting types in a PEX system, or should I try to find the same Uponor lines and fittings?
Edit: Looks like HD carries PEX-A and B from Apollo, so make sure what your store carries.
Uponor makes PEX-A and the Apollo found at Home Depot is PEX-B. Some fittings will only work for PEX-A and can't be used with B, but these are somewhat proprietary expansion fittings that rely on the extra flexibility of A. The good news is, you don't have those fittings. The poly fittings with stainless clench rings work with A and B as do the brass fittings that take crimp rings. These systems are safe to interchange.
The main issue with the crimp systems is the expensive tools you need to use them. You might be able to rent a tool, but I've never looked into that.
Another option are the push-on "Sharkbite" type fittings that also work with A and B. Some people shy away from putting them in walls, but they have a good safety record. On installs the crimp fittings are much cheaper, but when making changes or repairs, the extra money for a few push fittings is small in the grand scheme of the job, and they require no tools to install.
PEX comes in three types: Pex-A, Pex-B and Pex-C. These are classified based on the way the are manufactured. Pex-A is the only type that Uponor manufactures and is considered to be the best. Apollo manufactures both Pex-A and Pex-B. If your supplier is selling Sharkbite fittings, all sharkbite fittings will work on all three types of Pex. I have only seen Apollo expansion fittings and all Pex expansion fittings will only work with Pex-A due to the I.D.
If you have Uponor, you have Pex-A tubing. So the Apollo fittings (if that is what they have) should work since they are for Pex-A applications. If they are selling Apollo, they will know that the Apollo brass expansion fittings will only work on Pex-A so that's probably what they are selling. I would ask or simply read the description on the tubing.
There are two things,
As for whether or not it'll work, your only concern should be is the fitting valid for the type of tubing. In the case of Uponor they support,
Basically it boils down to this, a manufacturer certifies specific type of fitting and rings or clamps for their tubing, (or doesn't and uses totally proprietary parts like SharkBite.) In the case of Pex A, Uponor, most plumbers now seem to use F1960 which is commonly called expansion or "cold expansion" (since no heat is required). With a battery-powered tool these are the best simply because there is little room for user-error.
Your fittings sound like they're ASTM F1807 and not cold expansion because you have a stainless steel ring.
When it comes to mixing non-Uponor fittings into your plumbing system, according to the Uponor Warranty, and all PEX manufactures basically have the same warranty: Uponor Pipe with non-Uponor fittings reduces your warranty from 25 years, to 10 years.
I now want to add a tee for a hose bib
I would just ignore what other fittings you have in the house and use F1960 expansion. It makes everything easy. It's all around better. Upfront cost on a battery-powered expansion tool is worth it for me, it's an insurance policy in the event you have a freeze and want to fix things in 5 minutes.
Note that the outside diameter of all PEX lines, whether A, B, or C, as well as copper piping are all made to the CTS (Copper Tube Size) standard. The primary difference is inside diameter. PEX A has a thinner wall and the inside fittings are less restrictive to water flow. PEX B has thicker wall and uses thicker internal fittings that will combine to create more flow restriction.
