Flint & Walling Centrifugal Packages - end suction centrifugal pumps - Manual (Page 6)

6
95 North Oak Street • Kendallville, IN 46755
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NPSH FORMULAS
PROPOSED INSTALLATION
1. To calculate the NPSH available in a proposed
application, the following formula is recommended:
Hsv = Hp ± Hz - Hf - Hvp
2. Hsv-Available NPSH expressed in feet of fluid
3. Hp-Absolute pressure on the surface of the liquid
where the pump tanks suction, expressed in feet.
This could be atmospheric pressure or vessel
pressure (pressurized tank).
4. Hz-Static elevation of the liquid above, or below the
centerline of the impeller, expressed in feet.
5. Hf-Friction and entrance head loss in the suction
piping, expressed in feet.
6. Hvp-Absolute vapor pressure of the fluid at the
pumping temperature, expressed in feet of fluid.
PROPERTIES OF WATER
Temperature
ºF
Absolute Vapor
Pressure Specific
Gravity
PSI Ft. Water
60 0.26 0.59 0.999
85 0.60 1.4 0.996
100 0.95 2.2 0.993
120 1.69 3.9 0.989
130 2.22 5.0 0.986
140 2.89 6.8 0.983
150 3.72 8.8 0.981
160 4.74 11.2 0.977
170 5.99 14.2 0.974
180 7.51 17.8 0.970
185 8.38 20.0 0.969
190 9.34 22.3 0.966
195 10.38 24.9 0.964
200 11.53 27.6 0.963
202 12.01 28.8 0.962
204 12.51 30.0 0.961
206 13.03 31.2 0.960
208 13.57 32.6 0.960
210 14.12 33.9 0.959
212 14.70 35.4 0.958
214 15.29 37.0 0.957
216 15.90 38.4 0.956
218 16.54 40.0 0.956
220 17.19 41.6 0.955
222 17.86 43.3 0.954
224 18.56 45.0 0.953
226 19.28 46.8 0.953
228 20.02 48.6 0.952
230 20.78 50.5 0.951
240 24.97 61.0 0.947
250 29.83 73.2 0.943
300 67.00 168.6 0.918
350 134.60 349.0 0.891
Altitude
(Feet)
Barometer
Inches
Mercury
Atmospheric
Pressure
Boiling
Point ºF
PSIA (ft. water)
-1000 31.0 15.2 32.5 213.8
-500 30.5 15.0 34.6 212.9
0.0 29.9 14.7 33.9 212.0
+500 29.4 14.4 33.3 211.1
+1000 28.9 14.2 32.8 210.2
+1500 28.3 13.9 32.1 209.3
+2000 27.8 13.7 31.5 208.4
+2500 27.3 13.4 31.0 207.4
+3000 26.8 13.2 30.4 206.5
+3500 26.3 12.9 29.8 205.6
+4000 25.8 12.7 29.2 204.7
+4500 25.4 12.4 28.8 203.8
+5000 24.9 12.2 28.2 202.9
+5500 24.4 12.0 27.6 201.9
+6000 24.0 11.8 27.2 201.0
+6500 23.5 11.5 26.7 200.1
+7000 23.1 11.3 26.2 199.2
+7500 22.7 11.1 25.7 198.3
+8000 22.2 10.9 25.2 197.4
+8500 21.8 10.7 24.7 169.5
+9000 21.4 10.5 24.3 165.5
+9500 21.0 10.3 23.8 194.6
+10000 20.6 10.1 23.4 193.7
+15000 16.9 8.3 19.2 184.0