Does this valve have PB?

[NCMau]

I want to install this 4 spool valve in my tractor. According to the tag, it is a Parker, mod VDP II 000036, P/N 484 536. I tried to get info online, emailed the company for specs, but no response.
This valve, by the obvious OD faded paint is military but it is in excellent condition and actually, looks like it is never been used. I had it on a shelf for 30 years.
I am sure is going to work, but what I like to know, does it look like it has a PB?
There are two ports for inlet and two ports for outlet and one exe plug in the back, which I have no idea what it is.
Can anybody shed some light?

 

[J_J]

Most PB port are in the middle of the valve.

Look in all the end ports and see if one of the ports has internal threads either for a small hex screw or a larger PB sleeve that can be screwed in. Picture at bottom.

The purpose of the screw or the sleeve is to separate the valve galleries so the used cyl fluid will only flow out the OUT port, and cause the pump flow to pass through the valve.

If the cyl are using all the pump flow, there is no flow out the PB port.

With all valve in neutral, pump fluid flows through all valves and the PB port which is designed for high pressure, allows the fluid to flow to the next valve.

All valves in an open center hyd system are connected in series.

The last valve in the tractor is the 3pt and does not need PB.

 

[NCMau]

J.J.
I hate to ask this but what do you exactly mean by OUT ports? Do you mean the pressure ports that send fluid to the cylinders, or the return port. In any case, all the ports look basically the same. There are two inlets and two returns. Why, I don't know. I guess for convenience and they all have hex SAE plugs.
The only one that I question is the one showing below. It is right in line opposite to the relief valve. Looking inside, I don't see how this sleeve is going to provide a PB function. Maybe I don't understand it.
After I am done with the hydraulic installation, I have plans to an hydraulic motor to run a small mower deck for side hedging.
If my valve does not have PB capability, how am I going to connect the line for the motor?

Also I have another question. When you pull the valve lever towards you (as in lifting the bucket) does the fluid run from the front port (toward the front of the tractor) or the back one? Silly question but it helps me to know for sure in order to size the lines.

Thanks again for your time.

 

[J_J]

They are all out ports except the IN port/

The main OUT port connects to tank.

The work ports are both IN and OUT ports at different times.

The PB port , if you have one is the port that carries the fluid to another valve.

A PB port is modified to make it a PB port.

The pics are for illustration only.

 

[NCMau]

Okay J.J. I guess I don't have a PB port. So, being the case, can I connect a motor control valve to the return of the main valve and the return of the motor valve back to the tank return. A series connection should work, right?
Please let me know about the lever question too? Thanks.

 

[J_J]

I am not fully understanding your question.

If you are talking about a FEL lever valve, you have two work ports for a one lever valve.

If you pull back and raise the lever, you are causing fluid from the A work port to fill the base end of the cyl if they are connected correctly.

Both work port hoses should be the same size.

If you have no PB, it is not a good idea to connect the solenoid valve after the FEL valve as the FEL valve tank port is not designed for high pressure.

You could add a relief valve to a solenoid valve to relieve if the cyl controlled by the solenoid is at max pressure.

All valve should be in series.

You could use a flow control valve with relief.

Surplus Center - 3/8 NPT HYD FLOW CONTROL VALVE W/RELIEF RDRS137-08

http://www.surpluscenter.com/adspecs/AS9-064-38.pdf

You could us a divider valve and that will provide flow to the hyd motor at all times.

Divider valve with relief.

Surplus Center - 5/30 GPM PRINCE PRIORITY FLOW DIVIDER W/RELIEF

http://www.surpluscenter.com/Instruct/I9-4158-5.pdf

 

[J_J]

This page for Gresen hyd should explain the differences for the different outlets.

OUT port, used for standard open center hyd valve. Low pressure.

PB port used to pass potential high pressure fluid downstream to another valve.


Closed center plug blocks the flow of fluid from the pump and the pump goes idle until fluid is called for.

 

[NCMau]

I am not fully understanding your question.

If you are talking about a FEL lever valve, you have two work ports for a one lever valve.

If you pull back and raise the lever, you are causing fluid from the A work port to fill the base end of the cyl if they are connected correctly.

http://www.surpluscenter.com/Instruct/I9-4158-5.pdf

That's exactly the info I needed to know.... You pull back, the fluid flows from A work port (the one closer to the driver) to the base end of the cylinder.
Thank you.

 

[J_J]

Sometimes the ports are all in a row as ABCD.

A and C go to the base end of the cyl.

http://www.surpluscenter.com/adspecs/AS9-8185.pdf

 

[NCMau]

I guess when the time comes, I just have to connect it and pull.