Midterm Flashcards
the difference between the initial lift-off pressure and the pressure of the fully open position for a relief valve
Accumulation
a device that controls the position of the flow-control element on a control valve by automatically adjusting the position of the valve stem.
Actuator
a valve that operates by admitting fluid flow to the gate or plug and redirecting it 90° out the discharge port
Angle Valve
lubricant used on exposed valve stem threads
Antiseize compound
also known as self-actuating, these valves perform their specific function without external assistance
automatic valve
A valve named for the ball-shaped, movable element in the center of the valve
ball valve
any valve that is intended to block flow; also called an isolation valve. The term generally refers to gate valves
block valve
a bell-shaped dome mounted on the body of a valve, which provides a housing for the flow control element when lifted out of the flow
bonnet
manufacturer information on the body of a valve
bridgewall markings
an adapter threaded to permit joining of pipes with different diameters
bushing
valve characterized by their disc-shaped flow-control element, which pivots from its center
butterfly valve
mechanical valves that prevent reverse flow in piping
check valves
dome shaped element attached to the valve stem which
presses on the flexible diaphragm to restrict flow
compressor (diaphragm valve)
a collection of instruments that work together to automatically control a process; usually consists of a sensing device, a transmitter, a controller, a transducer, and an automatic valve
control loop
automated valves used to regulate and throttle flow; typically provide the final control element of a control loop
control valves
the equipment concerned with controlling the operation of an electrical device
controller
something flexible that serves as a barrier
diaphragm
a valve that uses a flexible membrane to regulate flow
diaphragm valve
a device made of metal or ceramic that fits snugly in the seat of a valve to control flow
disc
the part of a valve that regulates flow; that is, the gate or the disc
flow-control element
liquid and gas forms of matter (not solids).
fluid
the flow-control element of a gate valve.
gate
a valve with a movable metal gate in the path of a process flow
gate valve
a device that places a disc in the path of a process flow
globe valve