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 cannondale

  1. cannondale

    Pump Selection: low flow, high head, and highly abrasive

    I'd go either diaphragm or recip. Plenty of choice on pumps and materials, and pressure is no issue. I'm seeing the Putzmeister rep tomorrow so ill ask if I remember. I pump much larger particles and volumes/pressures with recips all the time, and yes valves and packings can be an issue, but if...
  2. cannondale

    precharge pump job on a high pressure water jetting machine

    Having mulled over this for some time, I'd recommend not experimenting. These pressures are extremely hazardous. Caution must be exercised when changing any equipment from its original build, especially for this application. Have you checked the pressure rating of the whole system (all its...
  3. cannondale

    Temperature change after compression

    I was kind of hoping for a mathematic solution rather than an online calc, but I got the answer I was looking for none the less, I just cant use it in a report very easily.
  4. cannondale

    High pressure valve seals

    I did try but cant see how I add a document as I don't have a web location to put as the url? Do I have to register a cloud (google etc) account and load to there and then post the link?
  5. cannondale

    precharge pump job on a high pressure water jetting machine

    It's all about NPSHa as already stated for the change pump, differential pressure, cavitation, and most importantly the nozzle size on your jet nozzle, oh and the line associated that gives you the back pressure. Changing the belt drive pulley isn't the answer, as the speed/torque availability...
  6. cannondale

    Temperature change after compression

    http://www.freecalc.com/ptemfram.htm Fluid is water Flow rate 450lpm Pump Head 2750m Pump Eff 95% Tank volume 5000ltr Recic rate 1hr result +36.61 C That's a typical example of a smaller pump test. However I've convinced them to use a 32m3 tank now, so approx. +5.7C in an hour which is much...
  7. cannondale

    PED question regarding equipment installed prior to PED

    From what I remember, this and a few other things only really get enforced when CE marking comes into play, and more importantly the re-work or refurbishment of that machine or piece of equipment. If "major" items are changed of replaced from within that machine/assembly, then a new assessment...
  8. cannondale

    High pressure valve seals

    I have a high pressure fluids application. The valve is a sliding spool type with the pressure acting inside a blind hole in the spool with a side port. When the pressure is reached the spool moves and the port lines up with another in the body and hence flow path is achieved. I'm trying to seal...
  9. cannondale

    temperature change and pressure rise gradiant for a PRV

    apologies, though maybe id hit different disciplines. Thanks for the help though
  10. cannondale

    Temperature change after compression

    LoL, yes they are pretty big numbers. They are for a pump test set up. Specifically a 375kw test in 30degC, approx. 70-80% humidity, and no facility for cooling the test fluid. Only maybe, more tanks and/or more water in the loop. Its not often we have to do it, but needs must an all that. This...
  11. cannondale

    Temperature change after compression

    Hi BigInch, That's exactly what I was looking for, but wanted to try and understand the math behind it.
  12. cannondale

    Temperature change after compression

    I'm considering the issue when using a PD pump. I've always used 95% eff fluid end, and 85% eff for the mechanical/driver. so approx. 5% as a heat/noise estimation. Acknowledged the friction through the choke (relief valve) would be where id expect the majority of the heat to come from. When I'm...
  13. cannondale

    Temperature change after compression

    Hmmmm I understand that there's a substantial difference between gases and liquids. However, why doe the fluid get very hot after running tests on a pump in a test bay with a circulation of fluid from a tank? I know the fluid gets hot, and I'm presuming there's a temp change where the...
  14. cannondale

    temperature change and pressure rise gradiant for a PRV

    I'm looking for some help. To calculate the temperature change of a fluid (water for example), when its pressurised to 345bar from atmosphere or 3bar maybe, and then what the temperature change would be when brought back to atmosphere again. Pressure rise gradient for a closed valve condition...

Part and Inventory Search