Piping hydraulics

[pickerandsinger]

OK Iv'e read so many posts I am totally confused...What I have is this....I installed the bypass block behind the manifold...I ran the pressure line to the in port of the spool valve...And the return port line to the lower hole on the installed block I put in between the manifold and the TC....Now where do I install the aux 1000psi pressure reducing valve...I think I know but I need an expert opinion...And my return line is going to the lower hole on the installed block as I mentioned...Should I install that to the Auxillary Tank that I have mounted instead... That tank goes to the fill plug...Its a single action Henderson loader so I assume I should install a hose from the port on the spool valve that would normally lower the loader and run it to the Aux tank...I'm also adding a double action cylinder to the bucket but I think I've got that covered after I figure the previous questions.First things first ...Its an open center double spool valve....Thanks Dave....

[ricky racer]

OK Iv'e read so many posts I am totally confused...What I have is this....I installed the bypass block behind the manifold...I ran the pressure line to the in port of the spool valve...And the return port line to the lower hole on the installed block I put in between the manifold and the TC.... So far so good Now where do I install the aux 1000psi pressure reducing valve... If you have an auxiliary valve with a built in pressure relief, you don't need another relief valve. I think I know but I need an expert opinion...And my return line is going to the lower hole on the installed block as I mentioned...Should I install that to the Auxillary Tank that I have mounted instead... That tank goes to the fill plug...Its a single action Henderson loader so I assume I should install a hose from the port on the spool valve that would normally lower the loader and run it to the Aux tank...Not knowing exactly what you have, all I can offer is the "return" or "out" line from the auxiliary valve should go to the lower port in the bypass block as you described. The A and B line typically goes the two ends of the cylinder of a double acting cylinder. Being a single acting cylinder, I would assume you are correct in plumbing the other A/B line to the reservoir but I will have to give that some thought and exploration. I don't know how much help I've been but others smarter than me will chime in. I'm also adding a double action cylinder to the bucket but I think I've got that covered after I figure the previous questions.First things first ...Its an open center double spool valve....Thanks Dave....

[pickerandsinger]

Thanks for your help Ricky....Ed and I have been discussing this as to whether or not an aux valve is needed....They're posts that say you do and Ed doesn't have one on his and it works fine...Thought I'd pose the question and look for an explanation...You're thoughts fall in line with what we both feel...Maybe Mr Becker will chime in with his thoughts...Dave

[Jim Becker]

I agree with everything Ricky said, except one point that needs a little more comment. If your control valve has a built-in pressure relief, you don't need a separate pressure relief valve. HOWEVER, if the built in relief is set for too high a pressure, say 2,500 pounds, you need to do something else to limit the pressure to the maximum allowed for the Cub. That is somewhere around 1,000 to 1,500 pounds. If the relief in the valve is adjustable and can be turned down to Cub range, that is all that is required. If it can't be adjusted to the proper limits, it is effectively not even there. In that case, you need to add a separate relief in the line from the Touch-Control manifold to the inlet of the valve.

Your hoses should be:
1) Touch-Control manifold to valve IN.
2) Valve OUT to the bypass block.
3) Valve RELIEF (or however labeled) to auxiliary tank.
4) Valve A to cylinder.
5) Valve B to cylinder.

If you have a one-way cylinder, A or B goes to the cylinder and the other one goes to the auxiliary tank. Choice of A or B determines whether push or pull of the lever raises the cylinder.

If you need a separate relief valve, it goes in the middle of hose 1 with the relief port connected to the auxiliary tank.

[ScottyD'sdad]

Jim, on my Wagner loader, a of the control goes to the cylinder. B port is plugged, on the valve. Loader works fine.
Ed

[pickerandsinger]

I would like to thank all those who responded.... I have the 1000 to 2500 Aux relief valve , so I will install it as Jim said and then the line will go to the spool valve inlet which starts at 2500 psi....I talked to the Prince factory and they told me to route the position you would normally use to lower the cylinder on a double action cylinder back to the tank on a single action cylinder...The path of less restriction will make the cylinder empty easier...Thanks guys , I value your input, it was very helpful....Dave

[Matt Kirsch]

An auxiliary relief valve has three ports, IN, OUT, and RELIEF.
IN comes from the hydraulic pressure supply (TC manifold)
OUT goes to IN on the spool valve.
RELIEF goes back to the reservoir.

As an aside, I have never seen an open center spool valve with a separate relief port, though. The ones I'm aware of simply relieve pressure to the OUT port of the spool.

[Jim Becker]

Ed,
Assuming it isn't a one-way valve built in a common housing that is also used to make two-way valves, I can think of 2 ways a valve will work with one of the outlets plugged.
1) The valve has a component that can be turned/slid to a second position to convert it to one-way. (Common feature of IH valves used in Hydra-Touch systems.)
2) The valve is dead-heading and popping off the pressure relief valve when it is lowering the cylinder.

Matt,
The separate relief port is more common in power beyond valves than simple two-way valves. In power beyond, fluid returning from a cylinder is dumped directly to the reservoir rather than out the OUT connection. The cylinder return and relief outlet share a single connection and hose back to the reservoir. I believe the original control valve of the IH 1000 loader worked this way.

If a valve that dumps the relief flow to the OUT connection is used on a Touch-Control system as we have been talking here, the relief valve ends up in series with the Touch-Control relief valve. If both relief valves are loaded at the same time, the pressures will add to each other. Pressure at the pump could reach the 2,000 to 3,000 range which could do some serious damage.

This application should really be using a power beyond valve, but I was hoping to not get into that discussion.

[pickerandsinger]

Prince Hydraulic Control Valve — 8 GPM, 2-Spool, Model# MB21BB5C1 ( IT CAN BE FOUND AT SURPLUS CENTER.COM ITEM # 9-7862 )



I
This Prince hydraulic control valve features a compact design that is ideal for small tractors and other low flow operations. SAE #8 ports eliminate leakage, enclosed handles eliminate exposure to elements. 4-way, 3-position spring center; can be converted to closed center or Power Beyond. 3500 max. PSI. 2000–3500 PSI adjustable main relief, factory set to 2500 PSI.

What's Included

(1) Hydraulic control valve
Shop PrinceShop Prince
Key Specs
Item# 204607
Manufacturer's Warranty 1 year Limited Warranty
Ship Weight 10.0 lbs
Max. Flow (GPM) 8
Inlet Port (in.) SAE 8
Outlet Port (in.) SAE 8
Working Port (in.) SAE 8
Max. PSI 3,500
Directional Control 4-way, 3-position
Spool (qty.) 2
Adjustable Release Pressure PSI 2,000-3,500, preset 2,500[+] How can we improve these key specs?

[Jim Becker]

That valve is power beyond capable. Set it up according to the directions that came with it. The "C" port should be connected to the bottom connection of the bypass block (hose 2 above). The "T" port should return to the reservoir (hose 3 above). The pressure regulation can only be lowered to 2,000 pounds. So use the separate regulator as described earlier.

Note that in the Surplus Center Q&A somebody asked about using it for a one-way cylinder. They suggested dumping the unused A/B hose into the reservoir as I said earlier.

[pickerandsinger]

Thanks Jim...I was up quite late reading about hydraulics ...I guess my only concern is that when you activate the spool valve to the retracting single acting cylinder and return fluid to the tank, are you returning it under pressure and will that pressure serve to cause problems in the TC and or pump when combined with the pump pressure....I do realize that pressure is created when the fluid contacts something and "blocks" it and when it is constantly circulating less pressure is created...I may just have answered my own question ....I am adding a pressure gauge also so I can check things...Thanks to all for their help...Matt, I'll be seeing you in a week or so and will update you on things....Ed , I think the blocking of the port you mentioned serves to put the relief valve into play in your spool valve when lowering your bucket...I'm sure someone will chime in if I'm wrong ...Thanks Jim you've been a great help as always....Dave

[Jim Becker]

Looks like you did answer your own question. The return flow from a cylinder has to have some pressure behind it, otherwise it would never move. But you want that pressure to be as low as possible. Any pressure there will use up some of the lifting capacity from the other end of the cylinder. You want the return flow to be under as little flow restriction as possible. You get this by dumping that flow straight back into the reservoir. Since the reservoir is vented, there is no pressure in it.

In Ed's setup, if the system is blocking when lowering the one-way cylinder, he would probably be able to hear the engine loading.

[pickerandsinger]

Thanks again Jim....Dave

[pickerandsinger]

Lift off this morning....Works slick...Not enough pressure to register on a 3,000 psi gauge on the return...Now to add the cylinder for the bucket....But thats dual action so I don't for see any problem yeah right...I have a piece of conduit in a conduit to measure the cylinder retracted and extended...Once again thanks to those who gave their advice... Dave