PEX Fitting Connection

PEX crimp fittings are compatible with all PEX tubing types A, B, C

First of all, what exactly is PEX?

PEX, short for cross-linked polyethylene, is a flexible plastic used for plumbing. The tubing has become quite popular over the years, replacing traditional copper and galvanized steel water supply lines. Homeowners can easily pick up PEX tubing from their local hardware store (or order it online) and complete DIY project upgrades or replace leaking pipes without having a plumber come out. PEX is utilized in over 60 percent of new construction residential water systems—a notable jump in use since its arrival in the US during the 1980s.

Types of PEX:

PEX-A is the most flexible and is suitable for use in all home water-supply plumbing needs. It is the most resistant to cracking due to freezing, as it can expand the most. PEX-A is more expensive than B or C, and has no major benefit over PEX-B besides its greater flexibility. PEX-A is manufactured using peroxide.

PEX-B is stiffer than PEX-A and has a tendency to want to return to its coiled state. PEX-B can still be installed easily and expands to resist cracking due to freezing as well. PEX-B is manufactured using a moisture-cure method, and has a higher resistance to chlorine, making it a solid choice in regions where water contains higher chlorine levels.

PEX-C is the stiffest of the three types of PEX, making it the most difficult to work with. It is prone to kinking and susceptible to cracks in freezing conditions. PEX-C is the cheapest option, and should only be used for small repairs that don’t require much bending. PEX-C is manufactured via an irradiation method.

Methods used to make watertight PEX connections:

Copper crimping is one of the most popular methods to connect PEX. You’ll need copper crimping rings and a PEX crimping tool. The copper ring slides over the end of the PEX tubing, then a fitting is inserted into the PEX. The copper ring is moved to the end of the tube over the fitting, so that the PEX crimping tool can crimp the copper ring and tube snuggly in place.

Stainless steel clamps (SSC) is a method that involves using a ratchet clamping tool to tighten stainless steel rings around PEX connections. The steel ring slides over the end of the PEX tubing before the fitting is inserted, similar to the copper crimping method. Then the ratchet clamping tool is used to squeeze a tab on the ring, tightening the ring around the tube and fitting.

Expansion connections are made by using a PEX expander tool to stretch and widen the diameter of the PEX tube before inserting the end of a fitting. After about 10 minutes, the PEX tubing will shrink back down to create a seal around the fitting. This method only works with PEX-A.

If you are looking for a fast and more secure connection that will stand the test of time, crimp tools are your better option. But if you want more flexibility without working more, go for PEX clamps.