Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross 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 jfaucher

  1. jfaucher

    Steel corrosion in standard air

    I'm not 100% sure I well understand the concept of sacrifical anode... someone could help me? I'm using an all-steel linear bearing in a room where occur standard conditions of air temperature and humidity. In this case, the corrosion of the track is not happening really quickly, but after many...
  2. jfaucher

    Diaphragm pump calculation for sizing

    I forgot to mention that my diaphragm pump will be compressed-air activated. Even if this kind of pump is still classified as positive displacement, its performance curve is not vertical at all. Therefore, the resulting flow depends on pressure losses. But should I considere only discharge side...
  3. jfaucher

    Diaphragm pump calculation for sizing

    Hi everyones, When I'm sizing a centrifugal pump for an hydraulic system, I'm looking for a pump for which the head rise at requested flow will meet the sum of suction loss and discharge loss at the same flow (assuming I'm pumping fluid from/to reservoirs opened to atmosphere, at same level)...
  4. jfaucher

    Compressed air pressure drop

    BigInch, I tried, as you recommanded, to divide my hose into small segments, doing iterative calculation in excel spreadsheet. The results looks good as long as I divide my hose in segments of 2 ft or less, giving a local pressure drop of less than 10% of total line as predicted. I assumed...
  5. jfaucher

    Compressed air pressure drop

    My problem is going as follow: an existing equipment is supplied with compressed air through a 24ft long flexible hose with an I.D. of 0.31". 20 SCFM at a minimum of 15 PSIG is currently required. Now, a modification to this equipment will increase the flow requirement to 28 SCFM. I want to...
  6. jfaucher

    Flow Coefficient for fluid other than water

    racookpe1978, My flow is laminar because I'm working with oil (not water) and the liquid temperature may average -20 degC. For example, at this temperature, the kinematic viscosity of my oil is 891 cSt, which gives me a Re = 35 at 6 GPM in a 3/4" pipe. Even at room temperature, my fluid has a...
  7. jfaucher

    Flow Coefficient for fluid other than water

    One more question: In most fluid mechanics handbook, they explain how to calculate minor loss from the loss coefficient factor "K", going like this: deltaP = K * rho * V^2 * 1/2 However, as for the Cv factor that we have seen previously, there is no correction here for viscosity. How to...
  8. jfaucher

    Flow Coefficient for fluid other than water

    Thanks guys for your help. Specialy this link from ione, exactly what I was looking for! Jean-Pierre Faucher, ing. www.cel-aerospace.ca
  9. jfaucher

    Flow Coefficient for fluid other than water

    That means if you have high viscosity oil with a specific gravity of 1.0, you will have the exact same pressure lost than if you have the same flow of clear water going through a gate valve, for instance? Jean-Pierre Faucher, ing. www.cel-aerospace.ca
  10. jfaucher

    Flow Coefficient for fluid other than water

    Thanks for your response! Know I have a better understanding of my problem... My system is laminar flow, since I'm pumping about 6 GPM of engine oil through 3/4 pipes. Am I correct if I guess a loss coefficient factor "K" for each component, in order to evaluate the pressure loss following this...
  11. jfaucher

    Flow Coefficient for fluid other than water

    I'm currently doing pump sizing calculation, so I have to determine the total pressure loss of my piping system. Most of commercial components like ball valves, check valves, strainers, etc. have experimental data from suppliers indicating the flow coefficient (Cv) for water at 60degF. If I want...
  12. jfaucher

    Joukowski formula in rubber hose (water hammer)

    I would like to evaluate theoretically the pressure rise occuring during a water hammer effect in a piping circuit which includes high-pressure blended rubber hoses. Joukowski formula is based uppon Young modulus of the pipe material, but how to evaluate this variable with a composite "pipe"...
  13. jfaucher

    Transient Vibration (Water Hammer???)

    I have a transient vibration problem on a test cell using a hydraulic dynamometer. An upstream pump is supplying 80 PSI of water pressure to a 4" I.D. pipe, which is controlled by a valve. Downstream the valve, 18 feet of (about) staight piping lead to an absorber dyno. When the valve is slowly...
  14. jfaucher

    High Speed Motor (26,000 RPM -- 20HP)

    I'm looking for a high speed electric motor (probably brushless DC) to supply up to 20HP at 26,000 RPM. It is a non-continuous application (periods of 5 minutes only). I will need to control the motor with a drive to accurately fix output RPM at different values for engineering testing purpose...
  15. jfaucher

    Flexure Plates for Turbine Test Rig

    I'm looking for suppliers (or engineering cues to design by myself) a set of 4 flexure plates that must support a turbofan engine and its adapter structure (approx. weight 8,000 lbf). These plates act as flexure hinges in order to transfert axial thrust to a load cell, but must support rigidly...

Part and Inventory Search