Centrifugal pump Net Positive Suction Head Available Calculation
System data
- Q = 1000 gpm
- 8 in diameter, 25 ft long aluminium suction line
- (Hazen - Williams C = 135)
- Water temperature = 65℉
- Water level remains constant during pumping
- Elevation is 1000 ft above sea level
We have to calculate Barometric pressure
K1 = Constant = BP in m of water if h in ft
K1 = 33.89 and
K2 = 1.69 * 10⁻⁸
h = 1000
BP = 33.89-1.17*103 *1000+1.69*108 *10002
= 32.74 ft
VPw = 0.72 ft ( Standard)
K = Unit constant = 385.9 for Ft; 435.7 for meter;
M1S =
For Reducer K = 0.3
For Elbow K=1.2
For foot valve K = 5.5
D = 8 in
Q = 1000 gpmb
SL = 25 ft
DD = 0 ft
NPSHa = 32.74-0.72-0.48-5.06-25
= 1.49ft