I have just aquired a Dan Foss orbital valve. it is a "Load Sensing" unit. it has 4 ports on the face of it and a smaller one on the the side. talking to a few people i figured out that the small port is the load sensing port. talking with a few more people i've figure out that i can't block this thing off. but i haven't gotten 2 people to agree on what to do with it. according to the surplus center the valve is an "open valve" meaning that fluid can constanly run through it. "closed valve" does not let fluid run through it at all times thus burning up your power steering pump. the rest of the ports are no problem. just this one on the side.

any one familiar with this thing? or know some one who is?

surplus center item #9-5479

call your local Caterpillar dealer aka "Empire". they have specialist for hydraulic systems.

It may be a return to sump or drain line.
Some systems use the oil exiting from the hand control valve for other valves/functions.
The drain line allows any internal leakage to be returned to the tank.

HTH
K.
:usa:

i belive you wanted a load reaction valve not a load sensing one but i could be wrong.

I had a valve like the one you are talking about and I can say one thing...It won't work.

I have a friend that works at a forklift place as a mechanic and we tried numerous things and nothing worked.

It would work as long as you were moving the steering wheel, but as soon as you quit steering, the pump started squealing because the orbital valve would not bypass.

That extra port goes to a priority valve, which allows you to use another piece of hydraulic equipment on the same orbital valve, but as soon as you touch the wheel it takes the power away from the the other piece of equipment and gives it to the steering.

We tried plugging it and plumbing it to the return, but it never did work.

I have a detailed schematic somewhere around here, but I can't find it. I'll keep looking and post it on here if it turns up.

The shop that you work for(I think I got that staight, you work there right?) called me the other day about this valve.

You can not use a load sensing valve with a constant displacement pump (ala. power steering pump). Load sensing valves are meant for variable displacement pumps or valve systems.


Sean