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  • pump controls

    Does anyone know if it is still possible to get a manual screw-out throttle and a manual relief valve on a real pumper? I hate the electronic governors but that is all I see anymore,despite some serious reliability issues (at lest in my experience). I am throwing around an idea in my head for our next truck in which hte electronic governor pad could be mounted on a small door which would swing open to reveal manual controls as backup. Anyone ever see anything like this?
    In time

  • #2
    I can't say I've ever seen what you're talking about with the access door, but you can still get the throttle control you're describing. The salesman will call it a "vernier" throttle (we considered it on our new truck). Personally I prefer the manual controls, but on our vollie department it's hard to get the guys trained, and for them to use it enough to remember, on how to properly pump a truck.

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    • #3
      The closest you will come to a manual throttle is available from Fire Research, and, I'm sure, others. But it's still an electronic control device. It looks the same as a hand throttle, and it does the same thing, but it's still an electronic control. The reason is that all engines today have electronic fuel ijection systems. There are no more mechanically controlled engines available, and haven't been for several years. Meeting the last couple of generations of federally mandated emissions standards was not possible with mechanically controlled throttle systems.

      Really though, the electronic governor systems available today are much more reliable than they were just a few years ago. What's really nice is that when a competent, knowlegeable pump operator sets one up, there's no more changing the throttle to try to keep up with ongoing opening and closing of lines. The throttle system will react and make the change before you even realize it was needed. As long as the water's there, the people on the (hand) lines never feel the difference.

      And although you want your pump operator close by and keeping tabs on everything, it unchains that person from the throttle knob. It allows for tasks like hooking up lines, pulling kinks out and similar duties that need to be done but might not be if the pump operator had to stay at the throttle.

      Good ol' relief valves are very much available and many departments still spec them.

      Stay safe out there, everyone goes home!
      Last edited by chiefengineer11; 11-01-2006, 06:01 PM. Reason: Clarification

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      • #4
        Is the Vernier an actual old time twist throttle that is connected to the trucks throttle via a hard (coat hanger type) wire or is a twist throttle that sends electric voltage signals to the engine computer. I thought it looked old fashion but sent signals.
        IACOJ - Senior Jake

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        • #5
          The vernier throttle that we use is made by Felstead and is nothing more than a twist action unit that acts like a rheostat to request more fuel through the engine electronics. Looks and acts like thold style but is still electronic. Not sure if they have completely done away with the manual relief valve systems or not.

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          • #6
            You can still get a mechanical relief valve for any pump. As stated, the vernier throttle is electronic, operating like the old cable type, but using the "cruise control" segment of the engine ECM. It is possible to get this throttle behind a door to use as a backup to an electronic governor, but it requires a toggle switch to select it in place of the governor, as it connects to the same circuit on the ECM as the electronic governor.

            In my area, electronic governors account for 99% of new deliveries over the last few years. They are very reliable. Too often in the fire service, opinions carry more weight than reality. The electronic components used on fire apparatus are state-of-the-art, and the failure rate is next to nothing. Give them a chance, and base your confidence level on actual experience. There's plenty of "opinions" based on little knowledge to go around.............

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            • #7
              I have had bad experiences with electronic throttling systems on two Pierce pumpers in two departments. The problems (no governing action on one truck and no throttling action on the other) recurred several times, even after trips back to the dealer. In my opinion anything that takes the operator so far out of the loop is great when it works but disastrous when it doesn't and so is probably not worth the risk.
              In time

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              • #8
                Originally posted by firehat87
                I have had bad experiences with electronic throttling systems on two Pierce pumpers in two departments. The problems (no governing action on one truck and no throttling action on the other) recurred several times, even after trips back to the dealer. In my opinion anything that takes the operator so far out of the loop is great when it works but disastrous when it doesn't and so is probably not worth the risk.
                All of the current systems that I am familiar with (I don't claim to be familiar with all the systems out there) have a throttle mode. If the pressure control mode fails, or if for some reason you want to maintain a constant engine RPM, you switch to "Throttle" mode. The vernier throttles mentioned by me and others are about the same thing as always being in "Throttle" mode.

                The relief valve you can have easily. Waterous, Hale and Darley will be happy to sell you all you want. But forget about getting something where a cable pulls on a linkage that pulls on a lever on an injection pump or throttle box on an engine, they went to the same place as open cabs and back steps.

                Bear this point in mind, and it doesn't just apply to this situation, it's a generalization: Every new development enables us to think and do differently; every new development requires us to think and do differently.

                Stay safe out there, everyone goes home!

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                • #9
                  If you have Detroit Diesels in your older trucks, meaning from the early 90's, you been "driving by wire" this whole time! When was the last time you stepped on the throttle and nothing happened? Probably never. Your electronic throttle at the pump panel is the same thing. I've seen problems with the pressure transducers at the pump, but the operator always has "throttle mode" to default to. Class 1 had a bad run on transducers.

                  Let's face it, mechanically controlled engines are gone and electronic ones are here to stay. Get over it.They are reliable.

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                  • #10
                    Originally posted by HFD147
                    In my area, electronic governors account for 99% of new deliveries over the last few years. They are very reliable. Too often in the fire service, opinions carry more weight than reality. The electronic components used on fire apparatus are state-of-the-art, and the failure rate is next to nothing. Give them a chance, and base your confidence level on actual experience. There's plenty of "opinions" based on little knowledge to go around.............
                    Exactly. I get a laugh out of all the "oh I wish we still had this and that" talk that always comes up. I've driven and pumped old school trucks (including Macks), and let's be real, they were often a pain in the backside. Far too often we let the warm feelings of nostalgia for yesteryear sweep over us, and we seem to forget all the negative things. If given the choice between pumping our 1997 Pierce with the DDEC electronic throttle and governor, or manually setting everything on our old 1972 Mack CF, I'll take the Pierce every time. We have never had a failure on any DDEC controlled truck, but plenty of times with the old cable throttles and relief valves we've had trouble.

                    To each his own though.

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                    • #11
                      Firehat- We have on our new engines the set-up you are describing. Agreed, the electronics are here to stay and definitely more reliable than 20 years ago. We spec the back-up because there are many things that can go wrong with the governor (flow and pressure sensors, fuses, additional wiring, other inputs). When you select the "manual overide throttle" it is just a direct 3-wire ECM signal to the engine without any other potential problems. (If there is a problem with the ECM wiring / control you are screwed regardless). Keep in mind when you switch to "manual" you have no pressure relief control. It is for emergency only. I do not recommend getting both a governor and relief valve, they will constantly fight each other to maintain pressure. ( The sales rep's will try to sell it to you though!)

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                      • #12
                        HFD,I've got an opinion on your "failsafe"electronics based on FACT. TWICE we've experienced a failure of electronic control systems with interior crews involved under heavy fire.COMPLETE and utter shutdown of pressure delivery NOT related to a bad transducer and unrecoverable in either mode.Now I know that you can no longer get mechanical controls but I've still got a couple and SPEAKING only for MYSELF I'm a lot more confident I'll have water with a mechanical truck. We work on computerized vehicles for a living and let me assure you a fool proof/failsafe electronic control/device system DOES NOT EXIST! Nor does foolproof software.In over a quarter century of operating mechanical rigs I cannot recall a time when you could not improvise a roadside cure to keep a mechanical truck working.Certainly NOT true of electronic versions. Yes,electronics are here to stay but you better have a back up nearby.If you have yet to experience a failure,YOU WILL,and it generally happens at the worst possible time.T.C.

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                        • #13
                          Governor vs. relief valve

                          Originally posted by FD1976
                          I do not recommend getting both a governor and relief valve, they will constantly fight each other to maintain pressure. ( The sales rep's will try to sell it to you though!)
                          '76 - I don't disagree with you on that point, we don't have a relief valve on our '89 Duplex/Quality which has a 6V92 Detroit mechanical engine and a Barber-Colman governor. We won't be getting a relief valve on our new Spartan/Toyne that is on order. It will be a Caterpillar C13 (2006 engine, thank you) and have an FRC Pump Boss governor.

                          But if the scenario develops where you had to go to your back up, you don't really don't have any protection, either. The Waterous relief valve does have a shut off that would take it out of the picture unless needed. With Hale, I would expect that you could just crank it way up. I'm not familiar enough with Darley to say how you could handle theirs. The caution that applies to any of them would be that every week or so you would want to exercise the relief valve. If not exercised regularly, the one thing that can be guaranteed is that when you need it, it won't work!

                          Stay safe out there, everyone goes home!

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                          • #14
                            Roadside cure to non-functioning pump governor/engine rpm controller is to have someone sit in the cab and operate the driver's throttle with his foot. Driver's foot throttle must have worked since you got to the fire didn't you?

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                            • #15
                              I believe, on some manufactures, when placed in pump it disables the pedal in the cab. So that may not work either.
                              IACOJ - Senior Jake

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