Check valve in the return line

[RobertHasty]

Hello, could you please help me review this circuit?

http://files.engineering.com/getfil...-b15a75d9c85a&file=2013-01-13_Check_valve.pdf

There's a 5 bar check valve in the return line. There's also a pressure switch set to 5 bar. What would be the purpose for this?

 

[hydtools]

No idea what the purpose of the 5 bar pressure switch is. You do not indicate what it is electrically connected to.
The 5 bar check valve is there because some component requires minimum 5 bar pressure in the return line.
The check valve on the telescoping cylinder input is indicated as pilot-operated to permit return flow to allow cylinder to collapse.

Ted

 

[Oldhydroman]

Is it possible that the switch is set to just above the pressure the check valve induces when there is an actual flow? Then when the flow stops (cylinder stalls on the way down or reaches the fully closed position) the switch will indicate that this condition has occurred.

Just a thought

DOL

 

[RobertHasty]

Hello guys, thanks for participating.

The 5 bar check valve is there because some component requires minimum 5 bar pressure in the return line.

Thanks for the tip. I thought it myself. This is really confusing because I have a meter-out throttle valve in the line. I don't know why do they have to make additional pressure drop.

Is it possible that the switch is set to just above the pressure the check valve induces when there is an actual flow? Then when the flow stops (cylinder stalls on the way down or reaches the fully closed position) the switch will indicate that this condition has occurred.

The switch is set at 5 bar, the same value like the check valve spring.

 

[hydtools]

The 5-bar check valve creates the pilot pressure to open the pilot-operated check valve on the cylinder port to allow the cylinder to retract.

Ted