D03 or D05 subplate and valve - Murphy proofing my 3rd function

powerscol · Oct 16, 2017

Ok folks - first I have spent several weeks going over this in my head. I want to thank ND2Fire, kennyd, Speedex, jabeling and Brian. I was choosing between a dirverter up front and a true 3rd function. Brian has previously set me up with a great kit to go from the rear remotes to the front grapple, but reaching for the remote lever is causing issues with my recently respired shoulder. All the plumbing is there from the rear down the left side opposite the loader control valve.

I have made a decision to go with the third function as I can go both to the front and back with a set of couplers by teeing off of the AB ports or line at or just beyond the valve and utilize of the hoses I have and by getting them cut with new ends. I will only be using one set (front or rear)at a time so this should work ? I also plan to get the John Deere grip and use relays. Power is handy off the fuse block spare location or rear of the tractor.

Now the delima I have a Bobcat CT235 with an open center loader valve (max flow is 7.9 GPM at about 3000psi (stock is 2600psi), This allowes me to us the line form the loader valve to the rear 3pt just as ND2Fire did. I also want a sub plate with P-T on one side and A-B opposite to have things line up. Right now my rear remotes lines to the front cross over the trans where N2Dfire set his up.

I had a long chat with my Bobcat dealer and also the local John Deer dealer that does a lot of custom hydraulics. When I am using my hay grapple I can get the system and hoses pretty hot. I have burned myself a couple of time trying to dis-connect my grapple too soon. Im running 3/8 lines from the stock rear remotes. Both folks, even though I have low flow recommended using a D05 sub-plate and valve to minimize any loses and reduce heat build up, especially at the subplate. The hard line from the loader valve to the 3pt is approximately 1/2 inch only metric. ND2 has listed the fittings I need at each end, so the only thing that will change is at the sub plate. I do know I want to go with 1/2" lines for the P-T and want the least restrictive fittings for both flow and heat. The JD man had a chart that showed up to 300psi pressure loss through the DO3 subplate and fittings at my flow rate. That could make a difference in my 3pt operation on max lift.

Northern tool has two sub plates that will appear to work with this valve http://www.northerntool.com/shop/tools/product_200329588_200329588 Northman Fluid Power Hydraulic Directional Control Valve 26.4 GPM, 4500 PSI, 3-Position, Double Solenoid, Tandem Center Spool, 12 Volt DC Solenoids, Model# SWH-G03-C6-D12-10 I know it is way overkill but the price is right. They have both a 1/2 : NTP subplate http://www.northerntool.com/shop/tools/product_200326792_200326792?isSearch=203341 Northman Fluid Power Single-Station Subplate NFPA D05 Pattern, 1/2in. NPT Side Ports, Model# M03-04-S-2
and a 3/4 one
http://www.northerntool.com/shop/tools/product_200333909_200333909 Northman Fluid Power Single-Station Subplate NFPA D05 Pattern, 3/4in. NPT Side Ports, Model# M03-06-S-2
Hopefully I have chosen a matching subplate for the valve and have the correct valve for my situation. the one with the 3/4 fittings is not listed on the valve page.

I don't know the pressure ratings on thees or the dimensions but will be calling tomorrow. Also anyone know anything about the durability of the valve? It has been mentioned in other threads.

These folks also have what I need and I can customize it. - Detail1 - Subplate - S5**-1/** - Steel D5 Side Ported Subplate - MANIFOLD - If I do go with these folks should I get aluminum or steel and what ports like 38SAE o-ring etc.

I do plan to make up a foam block replica of the unit before I order to check the mounting location for any interference.

If I am nuts here please let me know :confused2:

Any comments are welcome, including other valve or subplate recomendations

Thanks Keith

IceStationZebra · Oct 16, 2017

I don't know why you would need a DO5. A DO3 is good for 15-20gpm and the 1/2 line is only good for ~11gpm. Assuming this is for the CT235 in your signature, it only puts out 12.2 total (assuming the steering flow combines when not needed). Also you are not running a grapple continuously so some extra flow losses are minimal compared to the size of a DO5. You should also consider the current draw of the coils on a DO5 compared to a DO3. If you were to run something continuously like a snow blower the reduction is pressure drop would be worth the hassle.

I'm assuming the burns are caused by touching hot bare steel, which has a good heat transfer rate. One way to reduce the potential is to pain the steel.

ISZ

N2DFire · Oct 17, 2017

Hey Kieth,

I'd like to see his chart because what little I can find on the internet says 300 PSI loss at 20 GPM (Most of the information I can find is about the loss thru the valve itself).

The 2 things to remember here are 1) You're no where near 20 GPM & 2) Friction Loss VS Flow is a curve and not linear so at the 8 or so GPM you're looking at it should be less than 100 PSI.

Besides that, there are lots of companies making these kits with DO3 valves & subplates and yet I haven't heard of anyone reporting any issues related to them.

Now - all of that being said - the cost to switch from a DO3 Valve & Subplate to DO5 is minimal in the grand scheme of things so if it buys you peace of mind then there's no reason not to.

As to material choice - Aluminum all the way. It has much better heat absorption / dissipation properties than steel - just don't crank down too hard on any of your fittings putting things together.
Ports - I still think NPT with adapters to JIC is the best combo. No gaskets, no O-Rings, and JIC has built in swivel capabilities.

I will add one new piece of knowledge I just got last night. I am in the process of adding the rear remotes to our tractor and some of my hose routing is VERY close to the control levers/linkages and I'm going to have to end up putting in a couple zip ties to hold things off the levers so no vibration / impulse movement causes it to rub on the levers. Since you already have the rear SCV's then you should be able to work around them ok.

oldnslo · Oct 17, 2017

If this is a true 3 rd function valve it will be passing the full flow when the tractor is operating so pressure loss / heat generation is a valid concern. D03 sub-plates typically have 1/4 - 9/32 diameter holes for the valve mounting while D05 would have closer to 7/16 diameter holes. On 99.99% of D03 & D05 style valves the tandem center valve will have the highest pressure loss when flowing from P to T since the flow must travel through the center of the spool.

I am not familiar with Northman valves but in looking at Vickers & Rexroth data sheets it looks like both of these are around 50 - 60 PSI loss through a D03 at 9 GPM. This does NOT include the sub-plate, fittings, etc.

Also consider the flow velocity through the sub-plate: 9 GPM through a 9/32 diameter hole is approx 52 feet per second. Desired flow rate in constant flow pressure lines is 15 feet per second or less.

my two cents I would go with the D05 for a constant P to T flow application like this.

Confirm that the Tank port of the valve selected is also capable of being pressurized to your system pressure. Reason is that operating the 3PH will pressurize the tank port of this valve.

ericm979 · Oct 17, 2017

Its the D03 subplate that has a 300psi drop at 20 gpm. The holes in it are much smaller than the valve's. jabeling ported his and I was thinking of doing the same for my Branson's 10.5 gpm.

I think that the steering circuit is always separate from the main circuit, at least on my tractor.

powerscol · Oct 17, 2017

N2DFire said:
Hey Kieth,

I'd like to see his chart because what little I can find on the internet says 300 PSI loss at 20 GPM (Most of the information I can find is about the loss thru the valve itself).

The 2 things to remember here are 1) You're no where near 20 GPM & 2) Friction Loss VS Flow is a curve and not linear so at the 8 or so GPM you're looking at it should be less than 100 PSI.

Besides that, there are lots of companies making these kits with DO3 valves & subplates and yet I haven't heard of anyone reporting any issues related to them.

Now - all of that being said - the cost to switch from a DO3 Valve & Subplate to DO5 is minimal in the grand scheme of things so if it buys you peace of mind then there's no reason not to.

As to material choice - Aluminum all the way. It has much better heat absorption / dissipation properties than steel - just don't crank down too hard on any of your fittings putting things together.
Ports - I still think NPT with adapters to JIC is the best combo. No gaskets, no O-Rings, and JIC has built in swivel capabilities.

I will add one new piece of knowledge I just got last night. I am in the process of adding the rear remotes to our tractor and some of my hose routing is VERY close to the control levers/linkages and I'm going to have to end up putting in a couple zip ties to hold things off the levers so no vibration / impulse movement causes it to rub on the levers. Since you already have the rear SCV's then you should be able to work around them ok.

Steve he had a chart he made up that included a typical D03 sub plate, his gold plated Eton valves, and most critical the hoses and fittings. He assumed 1/2 inch hose to the typical 3/8 fittings for the estimated length of the tractor from the loader valve to the 3 point based on your set up. He indicated there was more loss through the fittings that the valve and hoses which makes sense. Being an engineer and working with water flow, the bends can add a lot of losses. He designs and builds custom hydraulics for construction equipment, and replaces and upgrade design flaws. I can ask for a copy next time I am over there - it 45 miles. Then again I am probably over thinking this as usual. Magnaloy has a D03 subplate that takes 1/2 " NPT fittings so maybe that is and option with the Surplus City valve that has the larger flow capacity. Lots mor to read.

Thanks everyone

lt190b · Oct 17, 2017

Keith, as N2DFire says the cost difference is minimal. I added a 3rd function to my farmall 40 to run a boom mount brush cutter. All the hydraulic flow travels thru it. May be my imagination but it seems like the performance of the tractor, while mowing with a 90" finish mower, was affected. I have since bypassed the valve, back to factory plumbing. Go with the bigger subplate and valve to match.

N2DFire · Oct 17, 2017

powerscol said:
Steve he had a chart he made up that included a typical D03 sub plate, his gold plated Eton valves, and most critical the hoses and fittings. He assumed 1/2 inch hose to the typical 3/8 fittings for the estimated length of the tractor from the loader valve to the 3 point based on your set up. He indicated there was more loss through the fittings that the valve and hoses which makes sense. Being an engineer and working with water flow, the bends can add a lot of losses. He designs and builds custom hydraulics for construction equipment, and replaces and upgrade design flaws. I can ask for a copy next time I am over there - it 45 miles.

Just to be clear - I'm not doubting him - I'd just like to see it b/c I can't find anything like that online (and I'm too lazy to drag out the books and do the math myself). Best I could find on simple Google search was the 300psi @ 20gpm and as I said before that's not a linear thing so it should drop drastically down at 8gpm

Somewhere back in a drawer somewhere I have an A.A.S. in MET (that I don't use much) & I teach "hydraulics" for Firefighting so I'm totally in agreement on the bend radius & effects on friction loss & laminar vs turbulent flows and all that stuff.

powerscol said:
Then again I am probably over thinking this as usual.

I think we all are. LOL

powerscol said:
Magnaloy has a D03 subplate that takes 1/2 " NPT fittings so maybe that is and option with the Surplus City valve that has the larger flow capacity.

Just keep in mind what oldnslo said because he's right on too - DO3 is a standard so regardless of what size input ports you have on the subplate (3/8" vs 1/2") - it's all going thru 1/4" orifices into the valve body anyway. So 1/2" on a DO3 might get you a little bit better performance, but now you're into a special order piece. You'd be better off to by an "off the shelf" DO5 set-up and be done with it.

It may not be sound engineering method, but I stand by the fact that W.R. Long, Construction Attachments, Bailey Hydraulics, and a whole slew of homegrown systems are all using DO3 and no-one has reported a blow up yet.

MtnViewRanch · Oct 17, 2017

N2DFire said:
Just to be clear - I'm not doubting him - I'd just like to see it b/c I can't find anything like that online (and I'm too lazy to drag out the books and do the math myself). Best I could find on simple Google search was the 300psi @ 20gpm and as I said before that's not a linear thing so it should drop drastically down at 8gpm

Somewhere back in a drawer somewhere I have an A.A.S. in MET (that I don't use much) & I teach "hydraulics" for Firefighting so I'm totally in agreement on the bend radius & effects on friction loss & laminar vs turbulent flows and all that stuff.

I think we all are. LOL

Just keep in mind what oldnslo said because he's right on too - DO3 is a standard so regardless of what size input ports you have on the subplate (3/8" vs 1/2") - it's all going thru 1/4" orifices into the valve body anyway. So 1/2" on a DO3 might get you a little bit better performance, but now you're into a special order piece. You'd be better off to by an "off the shelf" DO5 set-up and be done with it.

It may not be sound engineering method, but I stand by the fact that W.R. Long, Construction Attachments, Bailey Hydraulics, and a whole slew of homegrown systems are all using DO3 and no-one has reported a blow up yet.

Exactly. and if there were problems, I think that it would have shown up on TBN by now.

Really no reason to reinvent the wheel for this.

powerscol · Oct 17, 2017

oldnslo said:
If this is a true 3 rd function valve it will be passing the full flow when the tractor is operating so pressure loss / heat generation is a valid concern. D03 sub-plates typically have 1/4 - 9/32 diameter holes for the valve mounting while D05 would have closer to 7/16 diameter holes. On 99.99% of D03 & D05 style valves the tandem center valve will have the highest pressure loss when flowing from P to T since the flow must travel through the center of the spool.

I am not familiar with Northman valves but in looking at Vickers & Rexroth data sheets it looks like both of these are around 50 - 60 PSI loss through a D03 at 9 GPM. This does NOT include the sub-plate, fittings, etc.

Also consider the flow velocity through the sub-plate: 9 GPM through a 9/32 diameter hole is approx 52 feet per second. Desired flow rate in constant flow pressure lines is 15 feet per second or less.

my two cents I would go with the D05 for a constant P to T flow application like this.

Confirm that the Tank port of the valve selected is also capable of being pressurized to your system pressure. Reason is that operating the 3PH will pressurize the tank port of this valve.

OMG - you are very correct on this. Most D05 are at 2030PSI my pump pressure is 2611 - 3000. It was tweaked a bit. I need to be very careful on this. Most of the D03 valves are 3000, so close. The Northern tool valves wont work.