System expansion, relief valve question

   / System expansion, relief valve question #1  

CalG

Super Member
Joined
Sep 29, 2011
Messages
5,105
Location
vermont
Tractor
Hurlimann 435, Fordson E27n, Bolens HT-23, Kubota B7200
I recently added a three spool loader valve in a power beyond configuration.
The former configuration supplied the loader through the Aux control valves. the entire tractor hydraulics is protected by a main pressure relief.


The system is now: pump-- power steering via priority valve-- the new loader valve -- original pair of auxilliary ports -- three point lift. The relief has to be in there with the priority valve, as I see no seperate device. Unfortunately, I have not been able to obtain comprehesive literature on this S-L-H tractor

Everything works just fine.

The question came to me, What is the most beneficial setting for the relief on the newly added loader valve? Is there any good reason not to just screw in the adjustable relief on the new loader spool to some arbitrary (and unknown) value higher than system relief pressure.

I can't think of a reason why it should be less.

Comments?

tia

Cal
 
   / System expansion, relief valve question #2  
In my opinion, what you propose makes sense provided you're correct on the placement of the factory system relief. The relief MUST be between the pump and the load(in this case, your three spool valve). If you guess wrong, and the relief is actually somewhere downstream, raising the spool valve setting up too high can create a problem. Set it(or at least check it) with a pressure gauge. It's not a "guesswork" option.
 
 
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