Define the following terms:

Question

a. Ball valve
b. Block valve
c. Butterfly valve
d. Check valve
e. Control valve
f. Diaphragm valve
g. Gate valve
h. Globe valve
i. Multiport valve
j. Manual valve
k. Needle valve
l. Plug valve
m. Relief valve
n. Safety valve
o. Bonnet
p. Damper
q. Handwheel
r. Louvers
s. Packing
t. Throttling
u. Valve seat
v. Valve knocker

Answer 1

a. A ball valve is a type of valve that uses a flow control element shaped like a hollowed-out ball attached to an external handle to control flow.
b. A block valve is a valve used to block flow to and from equipment and piping systems.
c. A butterfly valve is a type of valve that uses a disc-shaped flow control element to control flow.
d. A check valve is a type of valve that allows flow in only one direction and is used to prevent reversal of flow in a pipe.
e. A control valve is a valve through which flow is controlled by a signal from a controller.
f. A diaphragm valve is a type of valve that uses a flexible, chemical-resistant, rubber-type membrane (diaphragm) to control flow.
g. A gate valve is a positive shutoff valve that utilizes a gate or guillotine that, when moved between two seats, causes a tight shutoff; it should never be used to throttle flow.
h. A globe valve is a type of valve that uses a disc and seat to regulate the flow of fluid through the valve body.
i. A multiport valve is a type of valve used to split or redirect a single flow into multiple directions or direct flows from multiple sources to the same destination.
j. A manual valve is a hand-operated valve that is opened or closed using a handwheel or lever.
k. A needle valve is a variation of a globe valve that controls small flows using a long, tapered plug.
l. A plug valve is a type of valve that uses a flow control element shaped like a hollowed-out plug attached to an external handle to control flow.
m. A relief valve is a safety device designed to open slowly if the pressure of a liquid in a closed space, such as a vessel or a pipe, exceeds a preset level.
n. A safety valve is a safety device designed to open quickly if the pressure of a gas in a closed vessel exceeds a preset level.
o. A bonnet is a bell-shaped dome mounted on the body of a valve where the valve disc is held when the valve is opened.
p. A damper is a movable plate that regulates the flow of air or flue gases.
q. A handwheel is the mechanism that raises and lowers a valve stem to control the flow of fluid through a valve.
r. Louvers are movable, slanted slats that are used to adjust the flow of air.
s. Packing is a substance such as Teflon® or graphite-coated material that is used inside the stuffing box to prevent leakage from occurring around the valve stem.
t. Throttling is partially opening or closing a valve to restrict or regulate fluid flow rates.
u. A valve seat is a section of a valve where the flow control element rests when the valve is completely closed; it is designed to maintain a leak-tight seal when the valve is shut.
v. A valve knocker is a device usually attached to a chain operator, used to facilitate the movement (opening or closing) of an overhead valve.