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fuel pump pressure

mreee22
mreee22 Member Posts: 3
anybody have high pump pressures from restricted return line ,had furn and wh bolth running higher than norm ,higher with bolth running,190psig ,wh flame would drop out,tripping cad cell relay,changed return line, all good now, my boss doing service since 56 told me, not possible,what i described ,

Comments

  • icesailor
    icesailor Member Posts: 7,265
    High return pressures:

    I've seen it a lot. Usually, you will blow the pump seals. Or, the pump outlet pressure to the nozzle will go up. Blow both the supply and return with compressed air. 10# is fine. I set my air compressor regulator to zero and slowly increase the pressure.

    If the return is restricted, it is probably full of sludge. In my opinion, it is not a good idea to switch lines for these reasons. And switching the plugged return for an open supply that is now the clogged supply, the higher vacuum will cause air that is dissolved in the fuel to come out of suspension and you will have a poor flame response. If the supply is good and the return is plugged, abandon the plugged return and install a Tigerloop.

    I have a customer that had a 2000 gallon UST replaced. It had sludged up oil lines. I used to blow back the lines regularly. It ran 1" to 2" of vacuum suction pressure "lifting" product from the ground. Now, they have a 2000 gallon above ground storage tank that when filled, has at least a 6' head of pressure at the pumps. But the suction on the pumps is 14" and rising. The installers kinked a line underground. The high vacuum pressure sucks the air out of the fuel and turns the Garber filters into vacuum chambers. The installers refuse to come back and fix it. They say it is normal. I told the owner that they were full of it and don't call me at 2:00 AM when the system goes down because someone will be digging up the concrete where the new lines are to replace the lines and it won't be me.
  • billtwocase
    billtwocase Member Posts: 2,385
    edited February 2012
    possible

    never seen it happen, but anything is possible. I have seen pump seals blow this way, but haven't seen a case where the flame was affected as of yet. I would drop the 2 pipe anyway. 
  • mreee22
    mreee22 Member Posts: 3
    fuel pump pressure

    thanks for replys,did blow back lines ,before changing ,air went through but  sludge sealed back up like tire sealant,cut out oil line sample pinched the end sludge came out like a  toothpaste tube , still cant figure the wh burner tripping out only when bolth running, 2 inches run vac,taken at filter vac gauge  at  tank , is     pressure back up 3450 burner furn somehow slowing   intake oil        flow on wh wich is 1725 ? would think any presuure would show up on vac gauge.
  • mreee22
    mreee22 Member Posts: 3
    fuel pump pressure

    thanks for replys,did blow back lines ,before changing ,air went through but  sludge sealed back up like tire sealant,cut out oil line sample pinched the end sludge came out like a  toothpaste tube , still cant figure the wh burner tripping out only when bolth running, 2 inches run vac,taken at filter vac gauge  at  tank , is     pressure back up 3450 burner furn somehow slowing   intake oil        flow on wh wich is 1725 ? would think any presuure would show up on vac gauge.
  • billtwocase
    billtwocase Member Posts: 2,385
    sounds like

    you may have a water problem. Is this an underground tank? Have you tried to treat the oil?
  • Ed N.Y.C.
    Ed N.Y.C. Member Posts: 73
    Pressure

    Ditto what Bill said. Do you have a vac gauge on both units. I would. Do you have a 30 psi gauge on return line, This will tell if return line is the problem. When in doubt use gauges   ED N.Y.C.
  • icesailor
    icesailor Member Posts: 7,265
    gauges:

    If you put any gauge on the return of the pump, make sure it is a compound pressure vacuum gauge. If you put a vacuum only gauge on the return and there is pressure, you may destroy the gauge.
  • icesailor
    icesailor Member Posts: 7,265
    gauges:

    If you put any gauge on the return of the pump, make sure it is a compound pressure vacuum gauge. If you put a vacuum only gauge on the return and there is pressure, you may destroy the gauge.
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