Two hydraulic questions

[rockinmywaypa]

Question #1
I purchased a used 3 spool valve which has an extra port that I'm not familiar with. Would it be part of the pressure relief but using an extra line to return to tank or might it be for a power beyond type of application. It is located right beside the outlet port. What purpose does this port serve?
Question # 2
I have a hydraulic motor that has been used on a self propelled forage wagon which I am converting back to pull type but I still want to have hydraulic drive via long hoses. On this motor there is a small hose fitting that is barbed so it obviously cant handle much pressure and it was ported back to the resovoir tank.You can see it located near the sprockets driving the wagon. I need a pump anyway and thought I would use this motor as a pump if I can but I don't know what use this nipple is for. I don't want it as a motor unless that nipple does nothing since I don't want an extra line to drag when using it. Can somebody tell me if I can use this as a pump and what reason there is for that line out to the tank.

 

[SPYDERLK]

I believe the purpose of that nipple is to return any leakage past the primary hi pressure shaft seal back to sump. That way you dont slowly lose hyd fluid from functionally inconsequential leaks.
...larry

 

[J_J]

Question #1
I purchased a used 3 spool valve which has an extra port that I'm not familiar with. Would it be part of the pressure relief but using an extra line to return to tank or might it be for a power beyond type of application. It is located right beside the outlet port. What purpose does this port serve?
Question # 2
I have a hydraulic motor that has been used on a self propelled forage wagon which I am converting back to pull type but I still want to have hydraulic drive via long hoses. On this motor there is a small hose fitting that is barbed so it obviously cant handle much pressure and it was ported back to the resovoir tank.You can see it located near the sprockets driving the wagon. I need a pump anyway and thought I would use this motor as a pump if I can but I don't know what use this nipple is for. I don't want it as a motor unless that nipple does nothing since I don't want an extra line to drag when using it. Can somebody tell me if I can use this as a pump and what reason there is for that line out to the tank.

The center adapter is probably your PB adapter. It looks looks someone was using it in the PB mode. It is also called a high pressure carry over.

The small third hose on the hyd motor s probably the case drain and either goes back to pump case or the tank.

Those fittings also look like water pipe fittings, and may not with stand the hyd pressure.

It is doubtful that you can use that hyd motor as a pump.

 

[rockinmywaypa]

Can I plug off the lines in both cases? Will it blow the seals out in the motor if I do?

 

[J_J]

I don't think so, as it may blow the shaft seals.

Excerpt:

Seal Failure
High case pressure results in excessive load on the lip of the shaft seal. This causes the seal lip to wear a groove in the shaft, eventually resulting in leakage past the seal. If case pressure exceeds the shaft seal’s design limits, instantaneous failure can occur. The subsequent loss of oil from the case may result in damage through inadequate lubrication.

 

[6sunset6]

I think the big port on the end of your valve is Power beyond. I think the smaller one is the return to tank line. If you do not want to use the PB you need a special plug and you need the return line to tank.
You also cannot plug a case drain line on a hyd motor.

 

[rockinmywaypa]

Thanks for the advise. I wonder where I would look to find the right plug to block the valve port since power beyond won't be needed or used in the application I have planned for it.

 

[N8ghz]

From the picture, it looks to be a Gresen valve. I think they were taken over by Parker Hanifin. You could try here for starters:

Contact
Hydraulic Valve Division
520 Ternes Ave
Elyria OH
UNITED STATES
44036-4026
Ph: (440) 366-5100
Fax: (440) 366-5253
HVDSALES@PARKER.COM

I have a valve similar to yours, but it doen't have all of the ports you ask about, although it is a 3 lever.

 

[wdchyd]

Thanks for the advise. I wonder where I would look to find the right plug to block the valve port since power beyond won't be needed or used in the application I have planned for it.

You will be able to modify the PB port adapter to standard usage....

Unscrew the adapter and expose the innards......if it is indeed a PB adapter then you will see internally that it separtates the inner pressure core with the return ports......all that is needed is the cut/machine off the area of the PB adapter that extends into the chamber (shorten it)....

the standard adapter is about half the length....

 

[J_J]

Take the fitting out ans take it to a hyd shop and they can match it for a hex plug. What you are doing is converting back so the total fluid and the expended fluid will flow out the OUT/tank port.

What kind of hyd valves are on your tractor now?

If you are going to add any valve downstream, you should use the PB outlet, even to feed the 3pt. or maybe a remote valve later.

Just run the OUT/TANK hose to tank, and PB port to the next valve.