A manifold is a device in a water system used to connect the supply and return water for various heating pipes. The material for manifolds used in underfloor heating and air conditioning systems should be brass, while those for household meter replacement in potable water supply systems are typically made of PP or PE. 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 front end. Each branch pipe of the water supply main should be fitted with a valve to adjust the water volume.