How to installing a PEX manifold system
You can install a PEX tubing system using a main branch and trunk lines as you would a copper system. But the material allows you to run lines from manifolds. In these system, copper manifolds feed multiple PEX tubes, with each run of tubing servicing one fixture. So you can have one manifold to service the entire house, or many, depending on the size of the home and number of plumbing fixtures it contains. Attach the PEX of the manifold outlets using crimp rings. Keep tubes organized with brackets and anchors.
The tools and materials you will need are: manifolds, copper tubing, PEX tubing, crimp rings, crimping tool, hammer, tubing brackets and anchors.
Step 1: A popular approach with PEX tubing is to extend each line from a manufactured copper manifold that is fastened to a wall. Advantage: litter pressure drop at one fixture when someone else uses another. Manifolds are available with shutoffs attached. Disadvantage: you waste more hot water waiting for it.
Step 2: Connect a new PEX line to each manifold nipple. In this way, each fixture has its own line. To conserve tubing, skip the manifold, and use conventional trunk lines with fixture branches. Codes vary, but limit each 1/2-in branch to two fixtures.
Step 3: To change direction abruptly, use a plastic 90-deg. bracket. Screw the bracket in place, and snap the tubing into it.
Step 4: Secure each fees line with a crimp ring. You will need a proprietary crimping tool for this function.
Step 5: Use plastic tubing anchors to gather the various fixture feed lines. These anchors come with nails installed. So they're quick and easy to attach.
Step 6: Install drain valves below the hot and cold manifold, and test the system with water. Be sure every fixture stub-out is capped or plugged, and leave the system under pressure several hours for a complete test.