Tank is a construction or a container, usually for holding liquids, sometimes for gases. The term can be used for both reservoirs and for manufactured containers. These tanks will have a small opening at the top and this opening will be used for filling the liquid or gases inside the tank so after filling the liquid the opening is closed by an adapter called tank adapter, which is generally a water tight adapter used for closing the tanks mouth. These adapters are of different types like bulk headed adapter, normal thread adapter, bolted adapter and adapter with O-ring for greater leakage production. These tank adapters are of both plastic and metals some of the plastics used for making tank adapters are PVC, CPVC, fiberglass & ABS.