BB3242
Mechanical
- Jun 21, 2007
- 9
Hey,
I have been searching through many of the threads that have arised and have become a bit confused. I understand about the NPSHr on the curve. I am looking into the NPSHa of the curve goign for VGO. I have a tank that is 40 Ft tall. Open up to Atmospheric press. I have all of the Line losses calculated with respect to the Kinematic Viscosity of the fluid.
Am I correct in using this equation?
NPSHa= Static Head + Head Due to Atmospheric pressure at top of the tank - Head due to line losses - Head due to Vaporization Pressure
H due to Patm= (14.7psi*2.31)/(sg of VGO liquid)
H due to Line losses = K* (Vel of VGO liq ^2)/ (2 * 32.214) For minor and = f* (Vel of VGO liq ^2)/ (2 * 32.214) For major losses
H due to Vap Pressure= (2.31*.49Psi)/(sg of VGO liquid)
Static Head = Height of the fluid above centerline of the pump
This is correct right I feel as though I should have to multiply the static height by the SG of the VGO fluid. Also even though the NPSHr is read as a guage pressure I should still calculate the Atmospheric pressure right?
Thanks for any help. I know there are alot of threads out there but I just became confused.
I have been searching through many of the threads that have arised and have become a bit confused. I understand about the NPSHr on the curve. I am looking into the NPSHa of the curve goign for VGO. I have a tank that is 40 Ft tall. Open up to Atmospheric press. I have all of the Line losses calculated with respect to the Kinematic Viscosity of the fluid.
Am I correct in using this equation?
NPSHa= Static Head + Head Due to Atmospheric pressure at top of the tank - Head due to line losses - Head due to Vaporization Pressure
H due to Patm= (14.7psi*2.31)/(sg of VGO liquid)
H due to Line losses = K* (Vel of VGO liq ^2)/ (2 * 32.214) For minor and = f* (Vel of VGO liq ^2)/ (2 * 32.214) For major losses
H due to Vap Pressure= (2.31*.49Psi)/(sg of VGO liquid)
Static Head = Height of the fluid above centerline of the pump
This is correct right I feel as though I should have to multiply the static height by the SG of the VGO fluid. Also even though the NPSHr is read as a guage pressure I should still calculate the Atmospheric pressure right?
Thanks for any help. I know there are alot of threads out there but I just became confused.