PEX Press Fitting

If done properly, crimp connections are an easy-to-learn, fast-to-install, inexpensive method for connecting PEX. Tools and rings are readily available at most retailers. Just remember to purchase separate tool heads for each pipe size.

These connections are approved for installation behind walls and direct burial in soil. However, when burying in soil, the copper crimp ring can be susceptible to corrosion, so it’s important to wrap the connection with an impermeable material.

The main drawback with crimp fittings is that they actually work against the properties of PEX. How? PEX pipe features “shape memory,” which means the pipe always wants to return to its natural shape. When the pipe is crimped down, it always wants to push back against the crimp ring — and away from the fitting — to return to its natural shape. Over time, this can lead to potential leaks if the installer is not using a go/no-go gauge and the crimp is a bit loose.

Another downside with using insert fittings is the smaller internal diameter compared to the pipe. This can restrict flow and decrease system performance. Also, being able to insert the fitting without formally making the connection can also increase the instance of dry fits.