Hydraulic divider question
- Thread starter etpm
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oldnslo
Super Member
You are correct in potential to dead head the pump and potentially damage something.
Rich B1
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- NH TC21D, 3 Craftsman GT’s…..old but tough, AGT Industrial QH 12
Did you look at your tractor’s hydraulic schematic or service manual? That should show you the location of the standard relief valve. If it is at the pump, then you are good to go. If not, then you need a relief between the pump and priority flow divider.
I have not been able to find a service manual for my tractor. I was able to buy a service manual from Hoye but when it arrived it was for a different model. Hoye told me that no service manual is available for my tractor but that the one they sent is close. In any case when the relief valve is functioning, such as when trying to pick up a load too heavy for the 3 point hitch, it can be heard and the sound comes from under the seat. Furthermore the manual that I have which is kinda close also shows the relief valve being located under the seat. So I don't think there is a relief valve at the pump. It looks like I will be buying a divider with a built in relief valve. I know I could probably buy a relief valve and just plumb it in but if I go that route I will need to make a mount for it and add extra plumbing. To keep things simple I'm gonna buy an adjustable divider with built in pressure relief.
Thanks,
Eric
So, now that I'm getting ready to buy a priority flow divider with relief I have a question about GPM rating. I think my tractor has an 11 GPM pump. I'm looking at one valve that's rated at 30 GPM. Would that be a problem? Could it make adjusting the flow accurately hard to do?
Thanks,
Eric
Thanks,
Eric
And another question. I looked at one sold by Summit that resembles others sold by many other places. But the description is slightly different. It says that for the relief to work the Ex port must be plumbed to the hydraulic fluid tank. Since my loader valve has power beyond and is open center and has a return to the tank won't it be safe to plumb the divider directly into the loader valve? The whole reason to use a divider?
Thanks,
Eric
Thanks,
Eric
oldnslo
Super Member
A 30 GPM rated valve may be a challenge to get set to 3 or 4 GPM for steering.
On relief valve question most relief valves the spring chamber is vented to tank port so any pressure in tank line is directly additive to relief setting. That is why Summit states must go directly to tank.
On relief valve question most relief valves the spring chamber is vented to tank port so any pressure in tank line is directly additive to relief setting. That is why Summit states must go directly to tank.
rScotty
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I don't know the flow of the YM2310, but 11 gpm sounds a bit too high for that size tractor.
I think that the YM2310 is similar to the US model YM276. Both use the same 3T84H engine set up to produce roughtly the same HP. In the US version the hydraulic flows 8.2 gpm at 2600 RPM. With that type of pump, flow rate is linear with RPM. If you run in the 1500 to 1800 RPM range with the FEL, you have something like 2/3 of 8 gallons or maybe 5.25 gallons/minute.
Look at how a flow divider works and you will see that it doesn't directly measure flow rate. It is using pressure and force to do what it does. Priority flow dividers work better at the upper part of their range.
Oldnslo says, "challenge". That's succinct.
Bottom line is: I doubt that the 30 gpm divider working at the bottom of its range has enough resolution to do what you want. It will do something...but I'm not sure what.
You might be better for something so critical as steering to use a proportional divider instead of a priority flow divider. It's worth a look. Take a look at the one Yanmar used as OEM in their tractors. It was sized for that very pump you have. If I remember right, the YANMAR hydraulic shop manual has a couple of pages explaining their divider. Maybe you could buy one....?
On Summit: Relief valves are typically plumbed to the sump, the hydralic reservoir tank. They rely on having very low back pressure. There is probably some exception, but I've never seen it.
Keep on it,
rScotty
I think that the YM2310 is similar to the US model YM276. Both use the same 3T84H engine set up to produce roughtly the same HP. In the US version the hydraulic flows 8.2 gpm at 2600 RPM. With that type of pump, flow rate is linear with RPM. If you run in the 1500 to 1800 RPM range with the FEL, you have something like 2/3 of 8 gallons or maybe 5.25 gallons/minute.
Look at how a flow divider works and you will see that it doesn't directly measure flow rate. It is using pressure and force to do what it does. Priority flow dividers work better at the upper part of their range.
Oldnslo says, "challenge". That's succinct.
Bottom line is: I doubt that the 30 gpm divider working at the bottom of its range has enough resolution to do what you want. It will do something...but I'm not sure what.
You might be better for something so critical as steering to use a proportional divider instead of a priority flow divider. It's worth a look. Take a look at the one Yanmar used as OEM in their tractors. It was sized for that very pump you have. If I remember right, the YANMAR hydraulic shop manual has a couple of pages explaining their divider. Maybe you could buy one....?
On Summit: Relief valves are typically plumbed to the sump, the hydralic reservoir tank. They rely on having very low back pressure. There is probably some exception, but I've never seen it.
Keep on it,
rScotty
I'm confused. I'm told I need a priority flow divider with a relief valve. So part of the flow goes to the steering and the rest goes to the FEL and 3PH. But what's the point of a priority flow divider with a relief valve if the excess flow must go directly to the tank in order for the relief to work? Then how am I supposed to power everything downstream from the priority flow divider and the power steering cylinder?
I guess I was way off in what I thought my pump put out. I have seen priority flow dividers that are 11 GPM max somewhere. I will need to buy one of those. If it will even work. I haven't seen any 8 GPM max ones.
Thanks,
Eric
I guess I was way off in what I thought my pump put out. I have seen priority flow dividers that are 11 GPM max somewhere. I will need to buy one of those. If it will even work. I haven't seen any 8 GPM max ones.
Thanks,
Eric
Well, I can't seem to find a divider with 11 GPM max flow. I found several rated 16 GPM max. I guess that's what I will need to get. Summit has conflicting info on their site. Looking at the 16 GPM model it says it can be used to power another function then lower down it says the ex port must be plumbed to a tank for the relief valve to work. I think it is just bad copywriting. Whoever is writing their copy doesn't understand what they are writing about and whoever is supplying the info isn't providing clear info. Which leads to confused and frustrated customers.
Eric
Eric