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!

Search results for query: *

  1. simar187

    Actuator Torque for Butterfly Damper

    Offset Butterfly Damper Specifications - 48" diameter - 0.75 PSI pressure drop - 100 degrees F - intended for GAS service - velocity is approximately 0.5 ft/s Once again, the sealing system is 316SST on 316SST. The seating torque will be minimal, but since its for gas service, I would like to...
  2. simar187

    Actuator Torque for Butterfly Damper

    I am trying to determine the actuator torque required for my metal seated, eccentric (meaning offset) butterfly damper. I am using formulae from Appendix A of AWWA C504-87, titled "Suggested Method for Calculating Torques Required to Operate Rubber-Seated Butterfly Valves". The formula for...
  3. simar187

    Butterfly Damper Torque

    I am trying to size the actuator required to operate my Eccentric Butterfly Damper. To do so, I am trying to determine the Hydroynamic Torque that air flow would induce in the damper's installed state. The software I am using is the Cosmos FloWorks plug-in for SolidWorks. The approach I am...
  4. simar187

    Hydrostatic Torque

    I have reviewed the inputs and all of the parameter solutions have converged. I think the problem may have something to do with where the torque and force parameters are being measured. I will be starting a new thread to address this problem. Thanks for your help.
  5. simar187

    Hydrostatic Torque

    Sorry about the confusion. The word "temperature" should actually be "pressure" in the following line: "and the approximate PRESSURE (NOT temperature) at my mass flow rate to 1atm+0.725psi" Furthermore, all pressure values that I input into CFD software and those mentioned in the initial thread...
  6. simar187

    Hydrostatic Torque

    I am using Cosmos Floworks to model and measure the hydrostatic torque that the flow of air would have on the disk of a butterfly damper. The mass flow rate of air at the inlet is 15.3125 lbs/s, the pressure is approximately 14.477 psi. Since the system has a pressure drop of 0.725 psi, I am...
  7. simar187

    Damper Torque Requirements

    In my above post, ?P is suppose to be delta P, the pressure differential, wherever used. Under dynamic torque, where it specifies: 5 deg < ? ? 90 deg It's suppose to be 5 degrees < alpha , 90 degrees, where alpha is the angle of disc opening. Simar
  8. simar187

    Damper Torque Requirements

    I am trying to determine the torque requirements of butterfly style dampers for air service. The dampers will be eccentric and range in size from 24" to 84" in diameter. Furthermore, they will be custom fabricated and NOT cast. The torques I am considering are Seating, Packing, Dynamic and...
  9. simar187

    Damper Leakage Test

    I forgot to include the leakage I am allowing. Since it is a Class IV, I am looking at 0.01% of damper capacity which is roughly about 4-5 SCFM.
  10. simar187

    Damper Leakage Test

    The size of the damper being tested for leakge is 16 inches. Furthermore, the standard I am trying to achieve is ANSI/FCI 70-2, class IV.
  11. simar187

    Resistance Coefficient, K

    Thanks for your help. The Hydraulic Handbook was very useful.
  12. simar187

    Damper Leakage Test

    I am planning on performing an AIR leakage test on a butterfly style damper intended for GAS service. My plan is to fasten blind flanges to both sides of the damper. One blind flange will have an air connection to connect to a air compressor. The other blind flange will have a flow meter...
  13. simar187

    Resistance Coefficient, K

    That is true. However, I'm a using the K value to determine my damper Cv. For preliminary calculations I have assumed it to be 0.25 for all damper sizes, but I need to verify and possibly correct this assumption.
  14. simar187

    Resistance Coefficient, K

    I am trying to determine the resistance coefficient, K, of a single-offset, butterfly style damper. Since, there is no readily available data for dampers I was going to utilize the K values of butterfly valves. Unfortunately, the formulas available are limited to sizes below that which I am...
  15. simar187

    Cv

    Thanks for all your help. I was able to arrive at a solution. Once again, thanks!
  16. simar187

    Cv

    I previously posted a thread, “Cv and acceptable leakage of air,” http://www.eng-tips.com/viewthread.cfm?qid=205910&page=1. In that thread, MikeHalloran, mentions that you can correlate Cv to air flow, but that he didn’t know how to do it off the top of his head. I was hoping either he, or...
  17. simar187

    Cv and acceptable leakage of air

    Hi Jim, First, this is a damper not a valve and ANSI/FCI says the test medium pressure will be as you said, 45-60 psi but it also says OR within +-5% of the maximum operating differential which would be 0.75 psi in our case at hand. So, if we were testing at 1.0 psi with air then it would...
  18. simar187

    Cv and acceptable leakage of air

    Many thanks for your reply Mike. Having checked out the thread you mentioned, we are still at a loss as to how we establish the acceptable air leakage in scfm that qualifies the damper to Class IV? And if we take a different tack, how would a manufacturer calculate the Cv of a given valve...
  19. simar187

    Cv and acceptable leakage of air

    We have a butterfly style damper for air service on an industrial system that was certified by the manufacturer as ANSI/FCI70-2 Class IV, which allows for a leakage rate of 0.01% of damper capacity. The Cv of the damper is 32042 and if we were to do a water test, at 1 psi differential, we would...

Part and Inventory Search

Back
Top