This is the easiest drip irrigation manifold system to use! Manifolds can be put together in minutes. They allow you to put the valves closer together than using standard PVC fittings. Other advantages are that valves can be quickly aligned and that systems are easy to add on to. The system shown below is set up for four valves. A Senninger Pressure Limit Valve (PRLV), which can handle constant pressure for the whole system, allows you to use a single regulator for multiple valves.