Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by Liad

  1. Liad

    High pressure limitation for equipment

    Thank you all guys. The pump has an internal PRV and I will add another rupture disc just in case.
  2. Liad

    High pressure limitation for equipment

    Yes, we thought about installing another pressure relief valve. the fluid is phenolic resin so ש blockage in the pressure relief valve is possible in a certain situations. The gear pump discharge maximum pressure is around 30 bar. The control will stop the pump after 2-3 seconds of very high...
  3. Liad

    High pressure limitation for equipment

    Hello, We plan to have a positive displacement pump that can get up to a discharge pressure of 30 bar. we will have a pressure relief valve after the pump that will work at around 10 bar, and a pressure transmitter after the pump so we can stop the pump if we reach 8 bar. I know that a pressure...
  4. Liad

    Gear pump failure against backpressure

    We use a servo motor to control the flow of the pump by increasing or decreasing the RPM of the pump (not Hz like VFD). we checked the shafts and coupling and there was no issue with that. It's a standard gear pump that one gear moves the other. The decrease in pump performance is like the RPM...
  5. Liad

    Gear pump failure against backpressure

    Thank you, guys. I will try to answer some of the questions: 1. please see a part of the P&ID of the system: 2. we run the pump without a PRV and the result is the same. we also run the pump in our workshop after the fault (the customer send the pump to us) and we connected it straight to a...
  6. Liad

    Gear pump failure against backpressure

    We run the system for different flow rates, it works fine until we set backpressure of more than 5 or 6 bar, in that pressure the flow goes to zero.
  7. Liad

    Gear pump failure against backpressure

    Hello All, We are dealing with a phenomenon of a very rapid drop in pump performance shortly after the system is activated. To go deep into the details: We have a tank with an agitator inside, there is a liquid inside(a mixture of water and oil) with level control. there is an outlet pipe going...
  8. Liad

    Pump in parallel - Fluctuations in flow

    Hey all, I will appreciate your opinion on adding booster pump as I mentioned above: Beside some mechanical changes, do you think adding a booster pump at the outlet of the tank on the 1.5" pipe will help? If yes, I will be happy to know what do you think are the parameters required to take to...
  9. Liad

    Pump in parallel - Fluctuations in flow

    Beside some mechanical changes, do you think adding a booster pump at the outlet of the tank on the 1.5" pipe will help? If yes, I will be happy to know what do you think are the parameters required to take to select the appropriate pump. I was thinking of taking a centrifugal pump with a flow...
  10. Liad

    Pump in parallel - Fluctuations in flow

    Hey all, Here is a picture of the design of the system: The connection to the lines going up to the pump is welded, the tees you can see behind is just for flushing. I guess and as you say, we have an issue that can cause a cavitation, maybe because of to much losses in the pipes. But my...
  11. Liad

    Pump in parallel - Fluctuations in flow

    Hey, So I meant we have full control on flow of each pump by a mass flow, and the pump is with servo motor. We did some tests, for example 10 LPM (this is a normal flow in these machine) with one pump we got a stable flow. When we tried to work with 5 LPM per pump x 2 pumps in parallels, we got...
  12. Liad

    Pump in parallel - Fluctuations in flow

    Hey all, Sorry for the delay, I will try to answer the question above: If these are gears pumps what do you mean when you say "The flow is the same in one/two or three pumps." Flow in total or flow through each pump? I meant if we work with 2/3 pumps the total flow for them is the same as a...
  13. Liad

    Pump in parallel - Fluctuations in flow

    Hey all, We are running a system with 3 positive gear pumps in parallel that installed at the outlet of a tank, like the picture below: The left pump is the closest pump to the tank. The outlet of the tank is 1.5", going up to suction of the pump is 3/4" for each pump and the discharge pipe is...
  14. Liad

    Heating calculations of flow in a pipe

    Hey All, We want to design a water heater that works with a constant water flow in a pipe. The pipe run in circles inside a water tank, the water in the tank is the heating medium. We want to get an estimate of the required length pipe. For this I take few assumptions: surface temperature is...
  15. Liad

    Pressure drop differences in piping

    Hello All, I got into a discussion with some other mechanical ENGs about pressure drop in pipe. We are running some tests for a gear pump and want to simulate a flow rate with back pressure in the end of a long line that as a connection to a 10 bar steam line. I suggest to use a short line and a...
See more

Part and Inventory Search

Back
Top