Let's talk valves for a moment (spool)

[Rayster]

Ok, I am looking for some clarification please.

I have a prince valve (open center) that has a detent operation. Meaning it stays in one of 3 positions. When it is in the center position, it lets the pressure off the load.

I made the assumption that once the cylinder was in position it would stay (yeah, bad assumption). So when the lever is forward and pressure is in the cylinder, does that pressure relieve itself and dump into the tank?

What type of valve is on the FEL?

I would like to add I have the option to make the unit a closed center. Is that what I need to do here, to operate my grapple correctly?

PRINCE MB11C5C1 MOTOR SPOOL VALVE




(I have another thread regarding my grapple, but thought a new thread would be better. My search for this information did not give me the detail I am looking for. So my apologies if this has been covered and I was unable to find it.)

 

[J_J]

Your hyd system is an open center hyd system and therefore the fluid has to be flowing all the time.

Pump flow is not feeding the cyl when in neutral, and the cyl is locked in it's current position, unless the seals are leaking.

You only want to use a motor spool valve when you are using a hyd motor, so the motor can wind down without causing damage.

What you want is a tandem center valve which is used in an open center type hyd system.

You also do not need detent using a grapple.

Why not use a diverter/selector valve and use the joystick lever to control the tilt and the grapple by using a push button on the joystick.

Surplus Center - 12 VDC 13.2 GPM SAE 8 DOUBLE SELECTOR VALVE

TANDEM CENTER VALVES
Tandem center valves when in a neutral position by passes the flow of hydraulic oil to the return line. This is used to hold the cylinder/piston in position with no load on the pumps. When this system is the pump is running constantly to keep a ready supply of hydraulic oil, but as long as the cylinder/piston is not in operation the pump is working under no pressure or load. This system keeps wear and tear on the pump down to a minimum.

OPEN CENTER VALVES
Open center valves are the same as the tandem center, except that in the neutral position all lines are connected back to the reservoir. The primary use of this system is to prevent "shock" loading when the valve is placed in neutral. This takes pressure off the motor. This system is used in situations where the operating device needs to be moved by hand.

 

[kenmac]

This https://www.surpluscenter.com/item.asp?item=9-7861&catname=hydraulic is the valve I used when I installed my grapple

 

[J_J]

You can use a lever spool valve if you want, but most people use one hand to control the joystick and the other hand to steer.

A simple push button and solenoid valve and the one hand does all the loader/grapple work.

 

[Rayster]

OK, thanks for clarifying that J_J. Thanks for the link Kenmac.

 

[banjodunn]

G'day are you sure that the valve is the culprit?? It may be seals in the ram bypassing and allowing you not to hold pressure.

Do not put a closed centre valve in an open centre system as you will 'dead head' the pump and the relief will be blowing all the time.

The detent is good if you want your grapple to be opening while you move onto your next job without you having to hold the valve and then it will kick out when the ram strokes out.


Jon

 

[Rayster]

Yes, I am going with an Open Center, DA cylinder spool, spring to center unit as J_J and Kenmac showed me. I'm not a fan of the detent type.

I opted away from the 12v unit, so I'm not dealing with the electrical system on top of the mechanical solution.