Manifolds are devices in water systems used to connect supply and return water for various heating pipes. In underfloor heating and air conditioning systems, copper is a preferred material for manifolds. For household meter replacement in potable water supply systems, manifolds are often made of PP or PE materials. Both supply and return lines are equipped with air vent valves, and many manifolds also have drain valves. A "Y" type filter should be installed at the water supply inlet. Each branch of the water supply pipeline should have a valve to adjust the water volume.