Sliding stem Valves Flashcards
A sliding-stem valve body is?
one where the moving parts slide with a linear motion
Globe valves restrict the flow of fluid by?
altering the distances between a movable plug and a stationary seat.
a needle valves are very common as…
manually actuated valves used to control low flow rates of air or oil.
what is a needle valve?
A valve in which the plug is extremely small in diameter and usually fits well into the seat hole rather than merely sitting on top of it.
What type of valve is this?
diaghragm valve
What type of valve is this
Gate valve
What type of valve is this
Double-ported globe valve
What is the purpose of a seat ring?
The seat ring acts as a guide for the plug to keep the centerlines of the plug and seat always aligned, minimizing guiding stresses that would otherwise be placed on the stem
purpose of a Double-Ported globe valve
The purpose of a double-ported globe valve is to minimize the force applied to the stem by process fluid pressure across the plugs
how do cage guided valves throttle flow?
cage-guided globe valves throttle flow by uncovering more or less of the port area in the surrounding cage as the plug moves up and down.
1- what is a balanced plug?
2- why would it be helpful?
1- A balanced plug has one or more ports drilled from top to bottom, allowing fluid pressure to equalize on both sides of the plug.
2- minimize the forces acting on the plug which must be overcome by the actuator
1- What type of valve is this
2- why would it be used?
- 3 way globe valve
- useful in services where a flow stream must be diverted (split) between two different directions, or where two flow streams must converge (mix) within the valve to form a single flow stream.
The purpose of the cage inside a cage guided globe vlave.
The cage serves to guide the plug so the stem would not be subjected to lateral forces as in a stem-guided valve design.
