Installing PEX water service connections in three easy steps
With crosslinked polyethylene, or PEX, now being the most installed plumbing-piping product in new-residential construction — more than copper and CPVC combined — an increasing number of product solutions are coming to market to accommodate a PEX plumbing system.
Take, for example, new fittings and valves that are now available for connecting PEX pipe to water meters using an ASTM F1960 cold-expansion connection. Before these direct connections were available, plumbing installers had to add an additional adapter fitting in between the meter connection and the PEX fitting. Now, they can directly connect from the meter to the PEX pipe with only a single part.
Here is a short, step-by-step guide for how to install the system in a residential application.
STEP 1: Install the water meter mounting bracket.
Because building codes restrict using PEX (or any other plastic piping) to support the entire piping system and meter, it is necessary to first install water meter mounting brackets. These brackets are specifically designed to hold the weight of the water meter. Simply whip out your screwdriver and drive in the screws to fasten the brackets to the wall studs at the proper distance to ensure the bracket will support the area where the connector (fitting or valve) is located (not the PEX piping). DO NOT support the meter with the PEX piping – mount the meter so the bracketry is supporting it.
STEP 2: Attach the fitting or valve to the water meter
Insert the tab into the nut and fasten the assembly to the meter. Be gentle — hand-tighten until it seats, then crank in an additional half turn. Don’t overtighten or you’ll be heading back to the supply house for a new one.
STEP 3: Connect the PEX tubing
Connect the PEX tubing after installing the fitting or valve. Place an expansion ring on the cut end of the tubing and use an expansion tool to expand the tubing and ring. After expanding, place the tubing and ring onto the fitting or valve. Make sure the tubing and ring are properly seated on the shoulder of the fitting or valve to ensure a proper connection. After a few seconds, as the PEX contracts back down to its original shape, it will create a strong connection onto the fitting or valve.