Hydraulic Spool Valve ID

Hi sawmilleng,

I've given you a GA. The only thing I would say is that with "mono-block"/"Bankable" hydraulic valves they have a spool configuration slightly different to the CETOP / ISO individual type valves in so much as the spool has 2 extra ports (internally) to feed oil to all the valves in the bank so that multiple valves can be operated together. It is still going to be a "pain" to identify individual spool configurations especially "motor spool". If there are any "slices" that have a plug in one of the two ports that should / could indicate a "single acting" cylinder spool.

Best of luck,

John

Hi

Go and get someone to help you or you will spend a lot of money and get nowhere.

There are plenty of hydraulic engineers in Ulster.

Regards

Oliver Dunthorne

Hydraulic Engineer

When I was doing a big hydraulic job, the salesman for the supplier was a great help to me. He helped me with the engineering, and I bought all the stuff I needed from him, a win/win situation.

Mike, very good point. I, too make use of the local hydraulics supplier sales guy.

George, if you took your valve and a big box of doughnuts to the local hydraulics supplier you might get your answers in a hurry! And they might have a suitable pump out the back if you are lucky!!

Jon.

OK looks like a open center valve, 40 liter per min, port A B blocked, service pressure 250bar, made by HyPro in UK V1000 model...still digging to see just what the spool is. Thanks so far for the answers learning quick. gs

Folks just to expand on the previous question. If I have a spool that is three position open center with blocked A and B ports is the diagram like this??

and will this happily run with a dual acting ram on the digger that locks the ram when in the neutral (centre) position. Thanks.

Hi mi3qtp,

No the valve symbol shows an "open centre" spool with all ports connected in the mid position.

The spool you describe has a centre position where P is connected to T (like an upside down "U" and A & B are like two separate small upside down capital "T"'s. where the T's are not touching the U.

Sorry can't figure out how to get a symbol into the message.

Best regards,

John

I have had a look at the CETOP cat at Flowfit and cant see any that match that ? nearest is the 3C6 ? The cat is here if you can take a look. cat7 George

Hi George,

That's the type. ignore the additional symbols each side of the centre position they are just to show the spool condition as it moves.

Best regards,

John

Thanks, I will talk to them on price etc..

OK I understand the diagram up to the side by side of the ABPT block but I am curious as to the condition during movement part :-)

Is the 3C6 spool what I would call a bang-bang (going back to my days of flying model planes and making RC systems :-)) in that the valve is open and shut no proportional between? Where as the 3C60 is more proportional?? Or am I still in the clouds with me planes :-)

GS

Hi George.

Your right it's a Bang Bang type of valve. Now bear with me on this (I'm prepared to be shot down in flames on this) I think the alternative spool transition types depends a bit on the application.

If you were operating a cylinder, for example, the "closed" transition type would stop the cylinder dropping as the spool moved. (does that sound logical?)

The "open" type would possibly be an advantage if you were operating a motor to minimise the shock as the spool moved.

Best regards,

John

For my limited knowledge Yes I think the Closed during transit type (3C6) is for my application of a extended ram which I want to remain LOCKED until told to move. I sure don't want the outrigger to move without comand...

If I used the other (3C60) the ram would be "bounced" on the fluid

I emailed Flow Fit guys and they replied (thanks lads) as follows...

This is the transient position, when the spool moves from neutral to left or right this shows whether all ports are connected or block during that brief nano-second.

So this backs up what you have said.

Hi George,

The application you mentioned "cylinder locked". It depends how "locked" you want it and for how long as you realise that there is a small leakage in a hydraulic valve and if you want it to "stay" you are better to fit a Pilot Operated Check valve (or valves) and if you do it a different spool centre position will be needed A & B to T with P closed.

Best regards,

John

Very interesting indeed. I went down to the shop today to have a look at what was actually installed on the unit. Now what I have is a total of 4 cylinders, dual acting. Each one (two front two back one each side) extends to stabilize the backhoe when in use. Each cylinder has a leaver that center neutral, push to extend, pull to retract. Now one cylinder on front and one on back has a (what looks like) a pilot operated check valve with a single small pipe leading from a lever operated on off valve? If I shift the lever to one position I no longer get any movement when I operate the main 3 position lever so I am assuming this locks the check valve This makes perfect sense and is what I want, the ram to be locked in place. What I don't understand is that this is only installed on one side, both the right hand side of the base. The other side has no locking device and remains fully operational when I move the main 3 position lever? I can send detailed photos and drawings if anyone wants to take a look. I can find no markings on any of the valves I will try and contact the original manufactures of the rig to see if they can tell me any more It is possible that someone has replaced parts at some time?

Hi George,

All getting a bit complicated isn't it.

The only thing I can think is that you can lock a set of jacks while the others remain operational to allow you to set up on uneven ground.

What do you think?

Best regards,

John