PEX is a flexible water supply tubing system, which is easy to install due to the fact that it doesn’t require solvent or soldering. PEX is made from cross-linked polyethylene and the sections join together using male-ended fittings which need to be secured with crimp rings. PEX can be installed for radiant heating and plumbing applications, in the same manner as any other pipe. IE, you would use main lines and branches to each fixture you are installing. However you may lose some of the benefits of PEX using this system because it needs a lot of fittings. To get around this problem, many household installations use a PEX manifold, which can be thought of as a junction box. Using a manifold means that you would install it in the utility room or some other area which would be close to both the main water line and water heater. There would then be the need to run a separate PEX tube to each fixture. You would then connect the incoming main water supply line to one end of the manifold, and then use multiple side inlets for each PEX pipe. This will mean that you can run pipes to each individual water fixture. You can get manifolds with or without shutoff valves to use on each individual line. It’s not difficult to install a PEX manifold, and few tools are needed. What you will need are:
- 15/8 inch wood screws
- Screw gun
- PEX crimp rings
PEX Manifold Installation Instructions
- Consider the correct place to position the PEX manifold, which would best be against a wall stud. Secure it into place using the wood screws and a screw gun. Make sure that the position of the PEX manifold is also near to the home’s water heater, and will be easily accessible. Should the manifold be for the hot water supply lines, make sure that the water heater’s outlet pipe can easily reach the manifold’s input port.
- Place a PEX crimp ring over the end of the PEX tubing. You will find that the supply pipe will generally be 3/4 inch diameter, and you need to push the end of this completely over the end of the manifold’s input port. Slide the crimp ring along the PEX pipe leaving a 1/4 inch gap between the end of the PEX pipe and the crimp ring.
- Open your PEX crimping tool, placing the crimp ring evenly within the ‘jaws.’ Firmly squeeze the handles together, making sure that the ring has been secured in place. Remove the handles leaving the ring in place and secure.
- Slide the crimp ring into both positions of a “go/no go” gauge. The ring ought to fit into the “go” slot, but must not fit into the “no go” slot. Should the crimp ring fail either part of this test, it needs to be removed and another different one should be installed in its place.
Attach every PEX pipe from each fixture to the side inlets on the manifold by using the exact same procedure.