Threaded metal valve Precise air control Long lasting These valves are meant to be screwed into PVC and are often used with a linear air piston pump to run an air loop around a room filled with aquariums. Build your own custom gang valve using these. These air valves will last a lifetime and are used by most fish stores and fish breeding facilities. Get a 3/16th drill bit to drill a hole into the PVC pipe. Then unscrew the drill bit and tighten the air valve into the drill chuck. Screw the air valve slowly into the PVC hole, being careful not to over tighten. Use a clean cut piece of airline tubing when attaching to the air valve. Periodically check for hardened aquarium airline tubing that may create a loose connection. For ultimate flow control in a fish room, we use the Ziss Plastic Air Valve near the aquariums for fine tuning, eliminating the need to get up on a ladder when using these metal valves in a fish room air manifold loop. For more details, read our article on how to build a DIY central air system for your aquarium fish room.