Valves Flashcards
What does a relief valve do? And how?
Limits system pressure.
Pilot line directs pressure to popit and popit opens at a certain set pressure venting flow back to tank.
Is a relief valve normally passing or normally non passing?
Normally non passing
Why do you have to have a pressure difference between relief valve and compensator?
Because of cracking pressure on the valve witch can cause loss of flow and excessive heat.
How do you set up a relief valve?
Our system pressure and gauge on one and 2 goes to tank. Gauge will tell you the pressure it takes to open valve
What does a sequence valve do?
Allows one operation to happen before another in a sequence.
Is a sequence valve normally passing or normally non passing?
Normally non passing.
How do you set up a sequence valve?
System pressure and gauge on one. And vent 2 and 3 to tank. The gauge on one will tell what pressure the valve will open.
What do you have to have with a sequence valve?
A by pass check valve because the valve is normally non passing and pilot is upstream of flow.
What does a pressure reducing valve do?
Reduces pressure after valve.
How do you set up a pressure reducing valve?
System pressure on 2. Put a gauge on 1 and dead head it. And 3 vents to tank.
The gauge on 1 tells you what pressure the valve will close.
Is pressure reducing valve normally passing or normally non passing?
Normally passing
What does a counter balance valve do?
Counter acts a heavy weight on a actuator.
(This is a motion controlled valve)
Is a counter balance valve normally passing or normally non passing?
Normally non passing.
What allows cylinder to stay out with a counter balance valve when dcv is centered?
The built in bypass check valve.
How to set up a counter balance valve?
When actuator is drifting turn spring counter clockwise until drift stops then turn turn 1/4 turn more counter clockwise.
