Posi Seal Butterfly Valve

butterfly valve
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
a valve in a carburetor that consists of a disc that turns and acts as a throttle
(Butterfly Valves) A valve consisting of a cylindrical body with a rotating vane to control flow. Tight Shutoff is obtained by an elastomer body liner into which the vane seats.
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
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.

posi
Also known as Positraction, which is a limited-slip differential (LSD) distributing power equally to both drive axles through a series of plates, clutches and springs.

seal
The water standing in the trap of a drain to prevent sewer gas from backing up through the drain, considered in terms of its depth
close with or as if with a seal; "She sealed the letter with hot wax"
A device or substance that is used to join two things together so as to prevent them from coming apart or to prevent anything from passing between them
The state or fact of being joined or rendered impervious by such a substance or device
make tight; secure against leakage; "seal the windows"
sealing wax: fastener consisting of a resinous composition that is plastic when warm; used for sealing documents and parcels and letters