This valve instead of pilot valves on cylinders?

JSUnlimited · Feb 24, 2006

I found this valve after I bought one from Surplus Center. If I used this valve, do I still need to have cylinders with pilot operated check valves for a top and tilt set-up? It's about $70 more and I can get it locally. Opinions?

2 spool 5GPM compact valve with pilot operated checks.

MMM · Feb 24, 2006

Don't you need a float spool for tilt part of TNT? I don't have TNT, but was just thinking on the order of stadard 3pt hitch float.
A comparison of check leak ratings might be in order also. 0.8L/min would roughly be 1/5thgal/min and if that much fluid loss would work, who knows? My loader load checks will hold a bucket of dirt up for days, but I don't know the specs to give you.

MadReferee · Feb 25, 2006

According to their schmetics, they have a double pilot check valve in there. What the manual doesn't give is the cracking pressure or the pilot ratio. These are important. The higher the cracking pressure the better, the CCM valves are 500 psi. FYI, thats the pressure applied to the dashed line (pilot control line) in the schmetic that goes into the check.

MadReferee · Feb 25, 2006

( My loader load checks will hold a bucket of dirt up for days, but I don't know the specs to give you. )

That is not what a load check does. The load check has nothing to do with how well the valve will hold up a cylinder when the spool is in neutral. The pilot operated check valve does that. Load checks are standard on just about every manufacturer's spools.

The load check on a spool will prevent the fall of a cylinder as the spool is shifted. It also prevents the backflow of oil from the work port to the inlet. It is functional only when the spool is shifted. Operationally, when the spool is shifted, the pump must build up enough pressure on the work port caused by the weight of the load before the cylinder can move. Sort of like preventing jerky operation.

Several of the Prince manuals give explanations of load checks and disclaimers that they function only when the spool is shifted, not when in neutral.

JSUnlimited · Feb 25, 2006

Thanks Ref, good point. I'll call Eaton on Moday and see what they say. Like I said I ordered that other valve you suggested for Surplus Center and then I found this one. I guess if the specs work out, I'll just return the one to SC and get the pilot one locally. Joe

rambler · Feb 26, 2006

( Don't you need a float spool for tilt part of TNT? I don't have TNT, but was just thinking on the order of stadard 3pt hitch float.
)

No..... Not changing the 3pt at all, it will still float like always. You are only replacing a vertical metal bracket with a hyd cylinder. This cylinder does not need to float - the metal bracket never did.

--->Paul

3RRL · Feb 26, 2006

Mega_Me,
I think that valve will not require you to have check valves on the cylnders as TNT does, since they are built in.
I recently read a thread sarted by Henro and he ended using that kind valve and has worked out real good for him. But he makes an interesting point...
Using that valve, if a hydraulic line between the valve and cylinder were to blow, the cylinder would lose lose pressure and leak down. If this happened with the check valves mounted on the cylinder, it would not lose pressure. One other slight minute consideration (may amount to didly squat) is any bulging of the hydrauic hoses would also affect the rigidity of the cylinder.

MMM · Mar 1, 2006

( standard on just about every manufacturer's spools.
)
I had to get back to states and look at my repair manual and be sure before spouting off. These checks are at work port's passages. It says verbatim that the 5/8 check balls contain the oil in cylinders until spool is actuated. There are also valves called control check, that might be related to what you speak of. Possibly this is a different check valve arrangement as it's OEM industrial, not aftermarket. There are other features I'm not sure are common, such as cushion valves and anticavitation valves.
All in all, it''s an interesting fact you've brought up and something to consider before I would replace this loader valve with the 3 spool I've been contemplating. As always you're a great asset to the forum.