Loader Valve Is Restricting Flow--Need advice

[npalen]

http://www.nimco-controls.com/virtupload/content/93/CV112.pdf

I have this valve on a Westendorf FEL new just this Spring. I'm having a problem with the valve passing a maximum of only about one third of its 12 GPM stated flow rate.
This is on a Mahindra 3015 (30HP) with a pump rated at 7.9 GPM.

I'm seeing, at 3000 RPM, a maximum flow thru the valve of 4.3 GPM and a back pressure of about 1250 PSI between the pump and valve when operating the bucket curl function.
I've been in contact with Nimco for some time now but having trouble getting answers.

So wondering if you guys might have some thoughts or advice which is appreciated.

Edit: Max flow is actually specified as 13 GPM on the valve.

 

[oldnslo]

Npalen
What pressure do you see with all the valves in spring center condition?

Does the lift - lower operate correctly?

If the lift - lower operates correctly and you have minimal pressure in the spring center condition I would move my pressure gauge to curl - dump circuit to determine where the restriction is. I.e. is it the valve or something in the curl circuit like a failing quick disconnect.

 

[npalen]

The pressure reading with the spools both centered is near zero as would be expected. I've taken pressure readings on both sides of the valve but will repeat to make sure that I've not missed something.
The bucket spool seems to be worse than the lift spool. It takes 19 seconds, for example, to curl the bucket in at low idle (1000 RPM), and that figures a bit over one GPM given the 2" bore x 1" rod x 21" stroke. High idle (3000 RPM) takes about six seconds (4.3 GPM) and both tests with the SSQA bucket removed so very little resistance from weight.

 

[oldnslo]

On your first post you mention 1250 PSI is the pressure you see while curling. Have you checked to confirm that you are getting full spool travel? Reason for asking is 1250 PSI seems low for the system relief but a partially shifting spool would cause the problem that you are experiencing. It would restrict flow which would then equate to pressure loss.

 

[RickB]

On your first post you mention 1250 PSI is the pressure you see while curling. Have you checked to confirm that you are getting full spool travel? Reason for asking is 1250 PSI seems low for the system relief but a partially shifting spool would cause the problem that you are experiencing. It would restrict flow which would then equate to pressure loss.

I agree. Spool travel is the first thing to check.

 

[npalen]

The spool travel is very short in my estimation. I double checked the measurements just now and am seeing 7/32" total travel on the bucket spool and 11/32" on the lift spool. Neither of these measurements include the float or regen travel but rather just the up and down and curl in and out.
I asked to speak with the service technician at Nimco in Sturdevant, WI but was told that he didn't have time to visit with me. They told me that I can send the valve in to have it checked but I want to be sure that a replacement valve will not have the same issue before going thru the mess of removing and shipping the valve. I offered to buy a new valve and then return the original for credit but they said that would have to be done via their dealer, Westendorf, but Westendorf does not warranty products made by other manufacturers.

 

[RickB]

Take the centering spring cap off the bucket spool and investigate. Check the spool travel with the cap off.

Westendorf warranty policy sucks if you are accurately describing it. What does your selling dealer say about all this?

 

[oldnslo]

Are those dimensions each way from center or total movement end to end?

If total movement I would agree that in not enough.

Can you easily disconnect the joy stick on one of the spoils and move the spool by hand to see if the travel changes? If the joy stick goes into float & regen I would suspect it is not a travel issue but this should be easier to check than removing the whole valve.

I will have to check tomorrow but I might have a Nimco valve in my garage that I can look at.

 

[npalen]

I can pull the cap off the spools and see if that allows any more travel in the lift up and curl in directions.
The spool travel for lift down and curl out probably won't change however since the spool traveling beyond those functions goes into float and regen respectively.
I'm thinking that the tolerances for the valve casting and spool land spacings are so tight that the tiniest out of tolerance on the casting would severely impact the flow past the spool.
When considering that the spool only travels 7/32" total for the curl in, curl out and neutral positions, that figures only about 0.070" travel for each position--barely 1/16'.
Seems like a casting core shifted just a few thou could start changing things, for example.

Edit: I believe system relief is set at 2200 PSI on the Mahindra and the loader valve relief checked approx 2000 PSI.

Edit: Westendorf warranty:
FAQ | Westendorf

 

[npalen]

Are those dimensions each way from center or total movement end to end?

If total movement I would agree that in not enough.

Can you easily disconnect the joy stick on one of the spoils and move the spool by hand to see if the travel changes? If the joy stick goes into float & regen I would suspect it is not a travel issue but this should be easier to check than removing the whole valve.

I will have to check tomorrow but I might have a Nimco valve in my garage that I can look at.

The dimensions are total travel end to end prior to going into regen.
I will try removing the joystick and checking spool travels but I don't believe that the joystick mechanism is restricting the travel.