Hydraulic Control Valve, T or P?

[pekabu]

Hi, I have this Cat control valve that has 6 ports. 4 ports are for the controls but that last two ports I don't know what they are. One Port is marked with a T next to it, and the other has P.

Any Ideas?
Thanks

 

[Bluecheck546]

P=pressure in
T=tank return
My2¢

 

[rambler]

</font><font color="blue" class="small">( P=pressure in
T=tank return
My2¢ )</font>

Would 'P' more accurately be Power Beyond? Which would be the pressure out tap on an open center control valve?

--->Paul

 

[Villengineer]

Standard port labeling convention on hydraulic valves is P stands for pump (high pressure input) and T stands for tank (low pressure return to reservior). With 6 ports make sure you know the flow paths so that you don't damage anything when you hook it up.

 

[pekabu]

Thanks for the help. It's like a bh valve, one stick but 4 functions.

 

[Villengineer]

I'm not familiar with the bh valve. Could you explain the operation? I use some single spool, 6 port valves on equipment that I design, but they are normally of the diverter or splitter type. I'm not sure that I've even seen a single spool 6 port w/4 functions in any of my catalogs.

 

[Henro]

<font color="blue"> Hi, I have this Cat control valve that has 6 ports. 4 ports are for the controls but that last two ports I don't know what they are. </font>

I think you want to be careful here to understand what you have before you use it.

My limited experience has taught me that with tractor open-center hydraulic systems, if you insert a control valve in the circuit, it generally has pressure in, power beyond out, and a return to tank port (3 ports) in addition to a pair of ports for each control section that will be operating a double acting cylinder.

From your description, you are missing one port. This is cause for concern.

Now it could be that what you have is a valve that has a power beyond capability, but that port is plugged, and requires some kind of adapter "plug" to enable it.

Before you do anything with that valve, you need to be sure than when the control sections are in neutral, that the inlet is connected to the outlet that passes the hudraulic fluid downstream, generally finally to the 3PH and then back to the tank.

Hope this makes sense. In my case, I am applying a four section control valve to my tractor, for T&T and other uses. This control valve has 4 pairs of ports (each will operate a double acting cylinder) and three other connections. One is pressure (flow) in, one is flow out (called power beyond) and the final one is return to tank.

The return to tank simply take the fluid expelled from a working cylinder and returns it to the tank.

Hope this makes some sense... /forums/images/graemlins/smile.gif

 

[MadReferee]

</font><font color="blue" class="small">( Thanks for the help. It's like a bh valve, one stick but 4 functions.)</font>

For your typical BH valve there is usually no power beyond which is why most BH's have to be last in the circuit and when connected the 3pt is disabled.

That said, P=pressure in, T=return to tank.