Flow control valves manage the flow of compressed air, oil, or fluids. Balancing valves control water flow and balance heat distribution in commercial and residential hydronic heating and cooling applications. Butterfly valves have disc-shaped mechanisms that open and close the valve. Globe valves have hand wheels and threaded stems that control a disc-shaped plug inside the valve to open or shut off flow. Control valves automatically regulate flow. Plug valves control water flow with tapered plugs that have one or more hollow passageways that allow fluid through the plug when the valve is open. Needle valves use a needle-shaped plunger that fits in a conical seat to restrict or allow flow. Saddle valves mount directly onto pipes to supply water where a low volume, low pressure stream is needed.