Pneumatic Valves Questions & Answers : Directional control valves start, stop or change the direction of flow in compressed air applications.
Pneumatic Valves Questions & Answers
1. What is the function of a pneumatic valve?
Answer :
Function of pneumatic valve is to control the pressure, flow rate and direction of air flow in pneumatic circuits.
2. How do you classify pneumatic valves?
Answer :
We can classify the pneumatic valves as
- Direction control valves
- Non – return valves
- Flow control valves
- Pressure control valves
3. What is the function of a Direction control valve?
Answer :
Directional control valves start, stop or change the direction of flow in compressed air applications.
4. Mention the application of a 2 way, 3 way and 4 way DCV
Answer :
2 way valves are used for ON-OFF conditions. Three way DCV are used to control single acting cylinders. Four way DCV are used to control double acting cylinders
5. What are functions of a check valve
Answer :
The check valves are used to allow free flow of compressed air in only one direction and it prevents the flow of compressed air in the opposite direction.
Since check valves blocks the reverse flow, they are also known as Non-return valves.
6. How do you classify the DCV based on construction?
Answer :
Based on construction we can classify DCV as
- Poppet direction control valves
- Sliding spool valves
- Rotary spool valves
Also Read : Field Instruments Questions & Answers
7. What are shuttle valves?
Answer :
Shuttle valves, also known as double check valves, are used when control is required from more than one power source. It can be used as OR gate fluid logic control valve.
8. What is a quick exhaust valve?. Mention its application.
Answer :
A quick exhaust valve is a typical shuttle valve.
The function of quick exhaust valve is to exhaust the cylinder air to atmosphere quickly.
It is used with spring return single acting cylinder to increase the piston speed of the cylinders.
9. Mention two functions of pressure control valve
Answer :
- Limit the maximum system pressure
- Regulate the force or torque an actuator generates
10. Mention five control elements used in valves
Answer :
Five control elements used in valves are
- Poppet (ball or disc),
- Spool,
- Piston,
- Diaphragm and
- Sliding plates.
Also Read : Tilting Disk Check Valves
Good
For me The term “pneumatic valve” can also have another meaning, other than the referring to the fluid being controlled as above. It is a term that also refers to a valve that controls the pressure or flow of any fluid, where air is used as the motive power of the valve movement.
Like above the valve can be one of many different types including globe control valves that have two or three ports. So when talking about Pneumatic Control valves , I thinks of any valve where air is the control signal, regardless of the process fluid.
we have samson 3248 control valve having 3277 actuators and 3730 positioner. it is cryogenic app control valve. it is operating well when pump is in off condition but do not operate when pump is running. what are the causes for that. ? (it is fail open control valve.)
Why does a piloted valve no longer function with a working pressure of P=150 kPa(1.5 Bar)?