Page 1 of 4 1234 LastLast
Results 1 to 10 of 31
  1. #1

    Join Date
    Dec 2003
    Posts
    579
    Location
    California , Idaho and a little island in Panama
    Tractor
    Kioti DK45TLB

    Default pressure relief question

    Can I just put a second pressure relief valve inline on my extra set of hyd hoses to my front loader add on attachnents ? Some need a very minimun pressure and others need all the pressure I can send . It would be nice just to turn a knob to regulate pressure . I don't want to bend any more parts !!! Big Al

  2. #2

    Join Date
    Jan 2004
    Posts
    5,974

    Default Re: pressure relief question

    I believe what you want is a flow regulator, but I'm no hydraulic expert. Maybe Mad will chime in with the answer. John

  3. #3
    Elite Member
    Rest in Peace

    Join Date
    Apr 2003
    Posts
    3,741
    Location
    New Hampshire
    Tractor
    Kubota B2710, IH TD6-62 dozer with Drott 4n1 bucket loader

    Default Re: pressure relief question

    You mean you want to control the flow to the cylinders to slow them down? Then you need some type of flow control, either a line restrictor or a special flow control valve on the work port side of the spool valve.

    Relief valves are used on the pressure side of the spool valve, not the work port side.

  4. #4

    Join Date
    Dec 2003
    Posts
    579
    Location
    California , Idaho and a little island in Panama
    Tractor
    Kioti DK45TLB

    Default Re: pressure relief question

    Hi Mad ,
    OK ,this is what I have going on . I have a custom built grapple added on to my existing loader bucket that has so much hyd. strength when the jaw's close that it can twist the mounting brackets for the ram and that is a solid 2" piece of steel tubing . I need to get less psi power but keep the same volume so it closes quickly . My other attachment that is in the "build works" now is a tree shear that needs all the psi and volume it can get . I was hoping I could just put something "in line" to work . [img]/forums/images/graemlins/confused.gif[/img] Since I can't use the grapple at the same time as I use the shear ,I was hoping I could reuse the same hyd. lines for both duties . Thanks for your input .
    Big Al

  5. #5
    Super Member RickB's Avatar
    Join Date
    Sep 2000
    Posts
    7,038
    Location
    Eastern NY
    Tractor
    Case 885, JD 730D, Ford 4000

    Default Re: pressure relief question

    How about smaller diameter cylinder(s) to operate the grapple? If the existing cylinder(s) came with the grapple and the grapple's own frame won't hold up to the pressure the cylinder(s) exert, it sounds like a lousy design.

  6. #6
    Epic Contributor jinman's Avatar
    Join Date
    Feb 2001
    Posts
    20,950
    Location
    Texas - Wise County - Sunset
    Tractor
    NHTC45D, NH LB75B, Ford Jubilee

    Default Re: pressure relief question

    Al, you should look at the Prince RD1850H Prince Hydraulics adjustable pressure relief valve. Its range is 1000-2500 psi. If you mount it on your grapple's cylinder, when you remove the grapple, you remove the valve. That way your shear will have full pressure.

    I'm not sure if this valve is a checkvalve in reverse, so you might have to add a checkvalve for opening your grapple.

  7. #7
    Elite Member
    Rest in Peace

    Join Date
    Apr 2003
    Posts
    3,741
    Location
    New Hampshire
    Tractor
    Kubota B2710, IH TD6-62 dozer with Drott 4n1 bucket loader

    Default Re: pressure relief question

    Jinman,

    The problem with putting a pressure relief valve, like the one you suggested, on a work port circuit is that you still have to have a return to tank hose since when the relief pops the fluid has to go somewhere, ie. to the tank.

    If you look at the hydraulic circuit diagram of the RD-1850 you will see it needs a return to tank.

    Pressure relief valves of this type are not designed to go in line. They simply monitor line pressure and provide the fluid a path to tank when the pressure exceeds the valve limits.

  8. #8

    Join Date
    Dec 2003
    Posts
    579
    Location
    California , Idaho and a little island in Panama
    Tractor
    Kioti DK45TLB

    Default Re: pressure relief question

    Hi Rick ,
    Yes ,I thought about that . I designed and built this grapple for extreme duty myself .So the only person I can go after is myself! [img]/forums/images/graemlins/blush.gif[/img] Most of it is 3/4" T-1 steel . The ram is set up like the newer bucket ram on a Cat or JD . Only one ram in the center . This thing is also a ripper in the closed position and it is unbelievable at how well it works ,except for ram pressure problem . I have it off the tractor now and I am looking at all my options now . It seemed like a relief valve might be my answer . Thanks
    Big Al

  9. #9
    MMM
    MMM is offline
    Platinum Member
    Join Date
    Nov 2003
    Posts
    800
    Location
    Winn Parish, LA
    Tractor
    Case 380B, Super C

    Default Re: pressure relief question

    Do you have power beyond at loader valve and third valve for grapple? There are many control valves with adj relief that would work for grapple. A little simpler than plumbing inline relief. Single spool valves for $40 are abundant on E-bay and Surplus Center, etc.

  10. #10
    Gold Member
    Join Date
    Sep 2002
    Posts
    411
    Location
    So. Colorado
    Tractor
    Iseki TS1610F 4x4

    Default Re: pressure relief question

    It seems to me that you would want a pressure regulator...or pressure reducing valve (PRV) dedicated to your lower pressure cylinder, tapped off from the main pressure loop. Of course it would have to plumb back in to the return, back to the reservoir. But I could be wrong...I would need to see the circuit.

    Bill

Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2013 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.