hydraulic spool valves in series

[drythropple]

Hi, some help please, I would like to plumb two sets of spool valves together without using a flow diverter as the pump is a bit small, if I take the return from one valve through a check valve and into the flow side of the other valve and then return to the tank, would this work?

 

[J_J]

If one of the valves has PB, just connect the PB valve first and connect the PB out to the next valve IN port.

With the levers in neutral, the full pump flow will pass through both valves.

All returns should go to tank.

Same volume will go trough both valves, unless you feather the first one.

Are you talking about single spool valves in series?

 

[drythropple]

Niether have a pb port and both are double acting and open centre

 

[leonz]

About your valves,

What make you think you need flow diverter?, and for what purpose?

In no uncertain terms should you install a check valve between EITHER valve bodies
As long as the in port of the second valve set is the same size of the out port of the
first valve you do not need a check valve in any circumstance!!!

 

[J_J]

The fluid in an open center is either flowing or being use. Should not check it.

Do you know the return port pressure ratings?

On most valves, the return port is not designed to handle the high pressure, and most have a limitation or about 500 psi.

Some have done it but most all manufacturers recommend that the return port go to tank.

If you put these valves in series, the second valve may cause the pressure to build up to the relief pressure and that will be reflected back to the return port of the first valve. Could damage the first valve.

A two spool valve could be used here perhaps.

One of the valves should have a relief valve, set to about 50 psi below the pumps max pressure.

 

[drythropple]

Thanks for your "input", both spools are 3 lever and the pump is the hydraulic pump for tractor so it will have an "in house" relief valve, I suppose Im just going to have to give it a try, Im not really bothered about damaging one of the spools I may end up having to buy a six bank valve anyway, I was hoping to avoid the expense

 

[J_J]

Actually you could use a flow divider to feed each valve with fluid and the output from each valve would go to tank.

A solenoid diverter valve will switch fluid between two valves.

Surplus Center - SAE 8 6 GPM DOUBLE SELECTOR VALVE 12 VDC P15544-2

A manual selector valve would work.

Surplus Center - 3/8" NPT 20 GPM PRINCE SELECTOR VALVE

A ball valve could be used to select which valve would flow.

Surplus Center - 3/8" NPT CARBON STEEL 7250 PSI BALL VALVE

Priority flow divider.

Surplus Center - BRAND PRIORITY FLOW DIVIDER