Hydraulic Manual Control Valves

Your system is 'master/master' rather than 'master/slave' configuration?

Thanks for the imput. I am going to try closed spool valves.

Normally closed is the setting of the actuator. It is in reference to the position of the ball when in operation (closed). It has nothing to do with the actuator other then the setting.

Ball valves come in two different configurations. Floating or trunnion. A floating ball-valve, seals on the down stream side. Using upstream pressure to push the ball against the seal, on the downstream side.

A trunnion ball-valve has floating seats and the ball is stationary. Usually seals on the upstream side. Using upstream pressure to push the seats, against the ball.

The dual controls, is most likely a safety feature, to prevent accidental operation.

Is your actuator pneumatic, elect, or mechanical? Scratch mechanical, you only have two hand's. Or you have some other issues. That I don't want to know about.

The actuators are both hydraulic rotary and rotate 180 degrees. One opens and closes a door while the other dumps a pan upside down and back. There is also a solenoid valve which prevent dumping if the door is open. When the door is open, the pressure is cut off to the dump, and the door functions fine. When the solenoid opens and pressures both valves, neither works unless both levers are pulled.

Are your levers in a control panel? and can you send a photo?

The levers are mounted to a plate on the side of the machine. I am not at the shop but I can tell you they are Manuel directional control valves mounted on a sub plate. There are 4 ports. P and T are pressure and return while I used A and B ports to and from the actuator. Both valves are the same. They share a common return line back to the pump. The pressure line tees with one going directly to the valve and the other goes through the solenoid before the valve.

"Why do my actuators work when both control levers are used at the same time but not when used independently? Does it have anything to do with the type of valve? ie: normally closed vrs floating?"

Did the valves ever function the way you want them to?

Sounds suspiciously like a Fail Safe feature designed into the circuit.

The valves need to work independently. This is a new machine. The valves are spring de tent. Last time I used normally closed but the pump got hot because it was dead headed all the time. Could this be the problem? I don't know much about valves. I can post a schematic tomorrow please check back and thanks

Is it operating as intended? Or is something broken? What is it that you are trying to achieve?

It sounds like each lever is designed to operate a specific function and you have to pull one lever and then the other to operate. These sound like versa valves.

They are easy to reconfigure, if I knew the intended purpose. And a photo or a schematic would help

hello, I am from china valve manufacturer .please goto my website ! my website:http://www.smsvalve.com

thank you !

China your web sit has nothing to do with valves!!!!!!!!!!!!

Here is the info on the valves, they are Northman HDG023C610N My mistake, not spring de tent but spring centered. The pump is set at 1200 psi. Three position, spool type is C6 (P and T) are looped. Here is a link to the valve http://www.northmanfp.com/pdf/ManualDCV.pdf. Thanks for your help

So you have a Northmen hydraulic Manuel control valve. But i still dont know what you are trying to accomplish. Or if it is malfunctioning.

What you need is a 2bank monoblock valve, open centre. Either valve will pressure the system when operated. Consult your valve supplier for details.

"Three position, spool type is C6 (P and T) are looped. "

Explain "looped"

For your operation you need to run Pump to Valve 1 "P" port, from "T" port run a line to "P" port of the second valve and from second vave pipe "T" to tank.

Make sure the valves can have high enough BACK PRESSURE at the "T" port or you will blow something when pressure builds in the first valve as the second actutor is operating. Seals at least blow, enough BACK PRESSURE and a housing can crack.

Also you must realize that operating the cylinders separately works great but operating them together will set up a series circuit that will add the working pressures of each actuator and could quickly cause pump flow to go over the relief valve.

It's in the Basic book: http://w ww.hydraulicspneumatics.com/200/eBooks/

Yes that will work, but this system was designed for use of two separate valves for safety.

He never wrote what he was doing to the machine. He did not respond, to whether it was operating properly.

This is not real high pressure, but it is enough to hert someone.

Ok guys, thats a lot of great input. This is a new system I put together from a schematic furnished by the engineering firm we build machinery for. Apparently they redesigned the system to work with different pump and valves to reduce heat buildup from dead heading the pump. I thought I had hooked something up wrong but it turns out you were right. The back pressure is keeping the valves from opening so we are going to a different valve that is closed when not in use and we are switching the pump to one that can constantly flow past the high pressure bypass and not overheat. Thanks for the help. P.S. I think that running the pressure out of the T port of one valve and into the P of the other would also have worked but I didn't get a chance to try it. The machine shipped to the mine today. Looks like I get a field trip!!

Thanks again for sharing your knowledge

Wayne