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  • Unloader?

    Does an unloader "hold" a certain pressure after the pump is off and assuming the drive side of the pump is not releasing any fluid?

    Thanks.

    J.C.

  • #2
    Re: Unloader?

    yes it does as long as it's the pressure style and not the soft start style.

    basically there's a small check ball and spring.

    rick.
    phoebe it is

    Comment


    • #3
      Re: Unloader?

      Originally posted by PLUMBER RICK View Post
      yes it does as long as it's the pressure style and not the soft start style.

      basically there's a small check ball and spring.

      rick.
      Any recommendations as to a the best kind.

      Thanks.

      J.C.

      Comment


      • #4
        Re: Unloader?

        Will an uloader always be releasing water somewhere regardless of pressure settings?

        Thanks.

        J.C.

        Comment


        • #5
          Re: Unloader?

          yes, it will either bypass in a small hose loop such as in a cart jetter with no holding tank. therefore you need to have overheat protection on the unloader to dump water when it heats up, or have a holding tank to recirc into such as a trailer or cart with 8-12 gal. surge tank.

          i have an electric jetter that actually stops the 2hp. motor when the foot pedal is released. this prevents overheating, but is harder on the motor and electrical circuit.

          rick.
          phoebe it is

          Comment


          • #6
            Re: Unloader?

            Ok, then I need suggestions for a valve in this application.

            See the brass-90 degree-valve coming off the pump about 30 inches up. It's connected to the drive/pressure side of the pump and "unloads" through the vertical PEX into the tank to the right.

            It is adjustable but is beginning to not perform as before. You can set it to unload at 800 psi pressure and it just keeps unloading until about 600 psi-then it holds. It would hold before at whatever psi you set it at.

            Now I replaced it with a Giant Pressure Actuated Unloader today and the new one would never stop unloading at any setting. Never build any pressure because it is constantly bypassing just like there is nothing there but a 90.

            So if an unloader is always releasing water, then what type of valve is in the picture as it can be set to hold water? Adjustable pressure relief? There is NOT a brand, stamp, marking on it anywhere.

            Thanks.

            J.C.
            Attached Files

            Comment


            • #7
              Re: Unloader?

              does the tank have a float valve?

              does the tank recirc back into the pump inlet?

              the part you spoke about is not an unloader, but a safety adjustable relief valve.

              see this link. http://www.pagegangster.com/p/HarDl/54

              rick.
              Last edited by PLUMBER RICK; 03-12-2010, 07:06 PM.
              phoebe it is

              Comment


              • #8
                Re: Unloader?

                Originally posted by PLUMBER RICK View Post
                does the tank have a float valve?

                does the tank recirc back into the pump inlet?

                the part you spoke about is not an unloader, but a safety adjustable relief valve.

                see this link. http://www.pagegangster.com/p/HarDl/184/54

                rick.
                Your link is not working. The tank has a pump on the other side pulling from the bottom of the tank and pumping into the inlet of the high pressure pump.

                The tank has a float control system related to another pump altogether. The float control system is NOT related to the fill pump or the high pressure pump.

                J.C.

                Comment


                • #9
                  Re: Unloader?

                  sorry, try again.

                  http://www.pagegangster.com/p/HarDl/54

                  page 54 top left

                  rick.
                  phoebe it is

                  Comment


                  • #10
                    Re: Unloader?

                    Thanks. Looks pretty close. What's the inlet and outlet connection? Male x Female? And what book is this from?

                    J.C.

                    Comment


                    • #11
                      Re: Unloader?

                      Seriously, I do need this and was wondering if anyone had good experiences or recommendations. Links to purchase too if possible.

                      A high pressure, adjustable, relief valve. Maximum pressure of 1000psi and a maximum flow rate of 20gpm. Temperature does not matter.

                      Thanks.

                      J.C.

                      Comment


                      • #12
                        Re: Unloader?

                        seems like all you want is a 20gpm unloader.

                        an unloader is just an adjustable relief valve.

                        The behavior you describe is odd... set a pressure and it bleeds down...

                        is this a continuous flow process? is the pump that makes the flow this thing is supposed to regulate on all the time? or is it like it's supposed to build up to 1000psi and hold it there static for a while, and the pump kicks off, and kicks back on when needed.

                        I'm asking because, really, there just isn't that much to go wrong with these things; it's just a seat and a spring. if the pump is running continuously, and there is little to no demand for long periods of time, I can see it wearing the seat from pumping everything across it all the time and it getting funny acting from that; not being able to close fully from the wear. a gob of goo or grit will make them act funny too... but you put a brand new one in, right?

                        I wonder if the pump is getting weak, and the pressure bleeds down during demand because the pump can't keep up anymore. does it lose pressure only when the downstream process is taking a bunch of flow? if so I'd be looking at the pump.
                        This is my reminder to myself that no good will ever come from discussing politics or religion with anyone, ever.

                        Comment


                        • #13
                          Re: Unloader?

                          jc, that link is from envirospec. the particular relief valve is rated for 12 gpm and is 3/8''. maybe add a tee and install 2

                          i can see if there's a 1/2'' model that will put out 20gpm.

                          rick.
                          phoebe it is

                          Comment


                          • #14
                            Re: Unloader?

                            Originally posted by Ace Sewer View Post
                            seems like all you want is a 20gpm unloader.

                            an unloader is just an adjustable relief valve.

                            The behavior you describe is odd... set a pressure and it bleeds down...

                            is this a continuous flow process? is the pump that makes the flow this thing is supposed to regulate on all the time? or is it like it's supposed to build up to 1000psi and hold it there static for a while, and the pump kicks off, and kicks back on when needed.

                            I'm asking because, really, there just isn't that much to go wrong with these things; it's just a seat and a spring. if the pump is running continuously, and there is little to no demand for long periods of time, I can see it wearing the seat from pumping everything across it all the time and it getting funny acting from that; not being able to close fully from the wear. a gob of goo or grit will make them act funny too... but you put a brand new one in, right?

                            I wonder if the pump is getting weak, and the pressure bleeds down during demand because the pump can't keep up anymore. does it lose pressure only when the downstream process is taking a bunch of flow? if so I'd be looking at the pump.
                            That's what I was thinking too. But apparently an unloader always unloads. Or at least this one does.

                            Yes, I did install it correctly and spoke to the manufacturer on the phone about it. They say based on my description that it sounds defective. But I'm not sure that it is being that it's a pretty simple design.

                            So I keep coming back to the question: Does an unloader always unload? Because this one never stopped one drop from coming through no matter where I set it. Then I took it apart and you can't blow any air through it with your mouth.

                            So that leads me back too...adjustable high pressure relief.

                            By the way, this is the ONLY unloader in my town. Not the only brand, THE ONLY ONE.

                            And when I ask for an adjustable high pressure relief valve everyone goes deer-in-headlights on me.

                            Thanks.

                            J.C.

                            Comment


                            • #15
                              Re: Unloader?

                              naw... something is wrong; if it's the style I'm familiar with (rick mentions another) it only opens to bypass when pressure bulds enough to lift the bypass valve off it's seat against the spring.

                              there are usually about a million ports on the thing and it takes a little bit of thought to make sure you've got the guzzinta and guzzottas in the right spots.

                              they come with different springs for different pressure ranges; might just be a really light spring? but you'd still see some pressure if tht was the case, and whatever spring it's got if you crank the thing all the way down it never opens at all.

                              you've either got a bad one or you had it hooked up wrong is my guess.
                              This is my reminder to myself that no good will ever come from discussing politics or religion with anyone, ever.

                              Comment

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