Why is this hard? Hydraulic sizing frustration

[MinnesotaEric]

All I want to do is add a third function valve and subplate in series to the fat 1/2" ID hydraulic line in the middle of this photo.

One problem is that my NX6010 flows just a little over 12 gpm and all of it, flows down that 1/2 line through three spool valves for the rear remotes and then the 3 PT valve before it goes to tank.

Thus I need electo-hydraulic open center valve that flows over 12 gpm and the right open center subplate that has 1/2" P and T ports. I can get a 16 gpm D03 valve, but for the life of me I cannot find a sub plate with 1/2" or SAE 8 (1/2") high pressure ports in a D03 size format because I don't know where to look. My local hydraulics guys at first thought I needed too tap into tank from this valve, complicating the issue further, and I shared this forum, explaining that everybody here is simple putting things series without and extra line to tank. Sadly, the need to research the right D03 sub plate.

All I need is a part numbers for the right sub plate and valve.

Then to top it off, this is the hose I need to tap into.

See the end on the left? My local hydraulic shops cannot size it to make custom length hoses. It measures 22.45mm ID and uses this special bolt.

The special bolt screws into this block with the blue cap on the back of my tractor. The flatness threw my local hydraulics guys off because there isn't a shoulder for an o-ring, the block is flat and the hose end has the shoulder to press on the o-ring. I had hoped we could screw in an adaptor and a 90 degree elbow and be off to the races.

I don't know why this is hard? But I'm not able to find the right parts and I'm not a hydraulic parts expert. To be clear: for all the time I've put into project, I have no idea what parts to use.

Should I just give up and try top make a simple diverter valve work up front?

 

[oldnslo]

Try Daman manifolds for your subplate. I am 99% sure they make D03 subplates with P & T ports #8 or even larger on their high flow versions.

From what you are describing this is a series circuit so I would be very, very hesitant to use a D03 for 16 GPM continuos flow. May even be pushing the performance limits on a D05 Tandem center spool.

That special bolt or fitting is called a "banjo" bolt and it may be difficult to get a hose end for that. They may use a seal washer Vs just an O-ring to seal.

 

[MinnesotaEric]

Talk to me like I'm 2 years old. Why would you hesitate to use a D03? If the sub plate is the same ID size and flows through, there should be much of the pressure drop and not much extra heat getting generated, no?

What don't I know?

Also, it looks like a banjo to me as well with two o-rings. Know a source for them so i can get hoses made?

 

[J_J]

12 GPM valve

http://www.baileynet.com/product/9262

Manifold 1/2 in ports

D03 manifolds

 

[kennyd]

Often, a BSPP fitting will thread into banjo ports. See if your local shop has any, or order some cheap caps and plugs online for "gauges". I'll help search for a subplate later...

 

[oldnslo]

The flow has to go through the valve in a series circuit. The holes on a D03 size valve are 9/32". D05 are 7/16. Also if look at the valve manufacturers data sheet they should show the pressure drop Vs flow for the different spools and possibly a "power envelope". This power envelope shows the point at which the valve malfunctions. Typically the tandem center spool is one of the worst spools since the flow has to travel through the center of the spool to get from pressure to tank.

example of a data sheet: do a google search for RA23178. This is Rexroth 4WE data sheet and look at the "G" spool curves.

Hose with the Banjo fitting, not sure who would have them. Typically Parker, or Eaton - weather head have a good selection of hose ends.

Does this help clear things up or just muddy the water some more.

 

[boggen]

cut the hose in half, get 2 couplers, 2 hoses, and 2 ends. and you can route the hoses were ever you want to route them.


you only show one hose, were is the second hose?

pump -> fel valves -> ""hose"" to rear of tractor -> valves for remotes on rear of tractor -> ""hose"" to reservoir assuming on front of tractor -> to pump.


as long as you have a open center valve for a 3rd function, it should not matter which hose you tie into. or were you tie into.

 

[Leejohn]

What is that lever for that is hooked to a spool?

 

[MinnesotaEric]

Often, a BSPP fitting will thread into banjo ports. See if your local shop has any, or order some cheap caps and plugs online for "gauges". I'll help search for a subplate later...

British Standard Pipe Paralel (BSPP). Got it. It would be great if I could screw in an adaptor, hang a 90 degree elbow and be off to the races. My basic idea is to used a sub plate with P, T, A, and B each on one side, with P, and T ports effectively passing through and the A and B ports with 90 degree elbows pointing forward so I can chance the hoses forward. I also entertained the idea of all four port having quick disconnects for purposes of servicing.

The flow has to go through the valve in a series circuit. The holes on a D03 size valve are 9/32". D05 are 7/16. Also if look at the valve manufacturers data sheet they should show the pressure drop Vs flow for the different spools and possibly a "power envelope". This power envelope shows the point at which the valve malfunctions. Typically the tandem center spool is one of the worst spools since the flow has to travel through the center of the spool to get from pressure to tank.

example of a data sheet: do a google search for RA23178. This is Rexroth 4WE data sheet and look at the "G" spool curves.

Hose with the Banjo fitting, not sure who would have them. Typically Parker, or Eaton - weather head have a good selection of hose ends.

Does this help clear things up or just muddy the water some more.

In other words, even though the ports are 1/2", the internal galleries are 9/32" and restrictive and pressure drop will be too great? or are you concerned about excessive heat building up? or the regulator popping continually? The hydraulic guys I spoke with looked at the rating and said I'd have a 100 PSI drop and they think i should be running from the valve to tank, but in another conversation, JJ said that parallel cuicuits are not the way to go and that I should keep everything in series with an open center system. FWIW, the machine regulates at 2650 PSI according to the service manual.

Question: I've never seen a sub plate or held one in my hand or seen a hydraulic schematic for one and so leading to my lack of knowing. In a series style subplate, does the subplate pass all the oil from P up through the open center, spring centered valve (assuming the valve is not actuated) it is bolted to and then receive the flow from that same valve and exhaust it out the T port or does a series valve port some of P to T without going to the valve it is bolted to. I ask because I'm trying to understand your pushback against a D03 or D05 valve.

12 GPM valve

http://www.baileynet.com/product/9262

Manifold 1/2 in ports

D03 manifolds

JJ, thanks.

What do you think about oldnslow's pushback against using a D03?

If I upped to a D05, do you know what valve and sub plate I should use?

Thanks!

cut the hose in half, get 2 couplers, 2 hoses, and 2 ends. and you can route the hoses were ever you want to route them.


you only show one hose, were is the second hose?

pump -> fel valves -> ""hose"" to rear of tractor -> valves for remotes on rear of tractor -> ""hose"" to reservoir assuming on front of tractor -> to pump.


as long as you have a open center valve for a 3rd function, it should not matter which hose you tie into. or were you tie into.

There is only one hose. This hose connected to the FEL valve's power beyond port and runs to the spool valve stack.

I was told at the hydraulic shop that my existing hose, because it is painted, couldn't be cut and recrimped. I did, however just look up the part number of the hose pictured in the bucket ( P/N T5535-42051 ) with the idea that a new, unpainted hose could get cut in half and new fittings popped on to serve my needs.

My plan calls for pump > FEL valve power beyond > hose <insert subplate> hose > spool valve stack > 3PT >tank. The FEL regulates and has a return to tank as well.

I currently have two push backs and I think they are on the same trajectory.

My local hydro guys want to use some type of sub plate that has a return to tank. I did not think that necessary given what people have shared here on TBN. I showed the parts that JJ suggested to them and they were not familiar with the sub plate and wanted to see how it is diagrammed inside.

oldnslo has raised what may be the same issue suggesting that the D03 sub plate is too restrictive.

 

[MinnesotaEric]

What is that lever for that is hooked to a spool?

You mean the knob or the lever in the first photo? The knob is a variable valve and speeds up or slows down how fast the 3PT works and the lever is the HST L-N-M-N-H shifter that one mussent touch when moving.