Hydraulic Top Link Question

Gordon Gould · Apr 24, 2010

I have been looking at top link cylinders and see that some have a check valve on them. I just cant seem to figure out what a check valve would
do. I could understand a pressure releif valve but not a check valve.
I assume it is a double acting cylinder operated off of a set of remotes.
Can some one explain.
THANKS

kennyd · Apr 24, 2010

Gordon Gould said:
I have been looking at top link cylinders and see that some have a check valve on them. I just cant seem to figure out what a check valve would
do. I could understand a pressure releif valve but not a check valve.
I assume it is a double acting cylinder operated off of a set of remotes.
Can some one explain.
THANKS

The valve ensures that the cylinder will not drift-it stays where you set it even if a hose blows.

The proper term is Double Pilot Operated Check Valve, so if you search the term "DPOCV" you will find more reading.

MtnViewRanch · Apr 24, 2010

The double piloted operated check valve (dpocv) prevents any hydraulic fluid from leaking by the control valve. This is a common occurrence and is most noticeable with smaller diameter cylinders, usually 2" diameter and under in size.

Yes these are double acting hydraulics. With a dpocv, you set the hydraulic where you want it and then there is no need to readjust it because it has leaked down and changed your adjustment. These are very good for use with a box blade.

I personally do not have the dpocv's on either my 2" or 3" "TnT" cylinders. I have not noticed any drift (leak down) on my 3" cylinder and minimal on my 2" cylinder. My terrain varies so much that I am constantly making adjustments and have not found that a dpocv would serve me any purpose as of yet.

A lot of TBNers use hydraulic top links from
CCM they only sell their top links with the dpocv. There is Surplus Center also, I hope that some of this may help you.