Cast Iron Butterfly Valves

butterfly valves
A valve consisting of a pair of semicircular plates that are attached to a spindle across a pipe and hinged to allow flow only one way
(BUTTERFLY VALVE) A valve with a circular body and a rotary motion disk closure member which is pivotally supported by its stem. Butterfly valves come in various styles including eccentric and high-performance valves.
A valve consisting of a disk rotating on an axis across the diameter of a pipe to regulate the flow, as in the throttles of many engines
(butterfly valve) a valve in a carburetor that consists of a disc that turns and acts as a throttle
A butterfly valve is a valve which can be used for isolating or regulating flow. The closing mechanism takes the form of a disk. Operation is similar to that of a ball valve, which allows for quick shut off.

cast iron
A hard, relatively brittle alloy of iron and carbon that can be readily cast in a mold and contains a higher proportion of carbon than steel (typically 2.0–4.3 percent)
Firm and unchangeable
an alloy of iron containing so much carbon that it is brittle and so cannot be wrought but must be shaped by casting
extremely robust; "an iron constitution"
Cast iron usually refers to grey iron, but also identifies a large group of ferrous alloys, which solidify with a eutectic. The colour of a fractured surface can be used to identify an alloy.