... butterfly valve Size: 2"--12" Interchangeable with Demco Model DM Butterfly Valve 1. Wherever face to face ... can be easily installed and uninstalled from almost any position of pipes or containers. 2. USAGE It is ... semi-fluid, gas, powder, etc., in a variety of industries such as petroleum, chemical, metallurgy, power plant, ... DEMCO type Butterfly Valve(Interchangeable with Demco Model DM Butterfly Valve)