141
Appendix F: Cavitation
Hale Products, Inc., Nov.2005, Rev-A
Cavitation
❑
During Operations
❑
Do not increase pump speed
beyond the speed at which
the pressure ceases to rise.
The higher the elevation
above sea level, the lower
the atmospheric pressure
and less lift. Lift loss is in
addition to NFPA Baseline of
2.38 ft. (0.73 meters) at
2,000 (610 meters) of eleva-
tion - see Figure F-6: “Lift
Loss from Elevation” on page 141.
❑
Open the throttle gradually and watch the pressure gauge and the tachome-
ter, if equipped. An increase in engine RPM without a corresponding
increase in pressure indicates cavitation.
❑
Monitor the water temperature. Figure F-5: “Lift Loss from Temperature”
shows the amount of lift loss as temperatures rise.
❑
Monitor barometric pressure. NFPA standard sets a baseline of 29.9” Hg.
(See Figure F-6a: “Lift Loss from Barometric Reading.”)
❑
Regularly inspect suction hoses to check for air leaks. Air leaks can also
cause cavitation.
❑
Check suction strainer for blockage or effectiveness. See heading “Strain-
ers:” on page 142.
Preventive Measures
❑
Consider the size of the suction hose. Figure F-7: “Hose Size vs. Pump Rat-
ing Capacity” on page 142, lists the NFPA pre-selected hose sizes for each
pump-rating capacity. Using the appropriately sized hose minimizes the
occurrence of cavitation. An undersized suction hose can lead to cavitation.
Water Temperature
F° (C°)
Lift Losses
Head Ft. (Meters)
60°
(16°)
NFPA Base Line - 2.38 (0.73mm)
70°
(21°)
0.3
(0.09)
80°
(27°)
0.6
(0.18)
90°
(32°)
1.1
(0.34)
100°
(38°)
1.7
(0.52)
110°
(43°)
2.5
(0.76)
Figure F-5: Lift Loss from Temperature
Elevation, Feet (Meters)
Lift Loss, Feet (Meters)
2,000
(610)
NFPA Base Line - 2.38 (0.73mm)
3,000
(914)
1.1
(0.33)
4,000
(1,219)
2.2
(0.67)
5,000
(1,524)
3.3
(1.00)
6,000
(1,829)
4.4
(1.34)
7,000
(2,134)
5.5
(1.67)
8,000
(2,438)
6.6
(2.01)
9,000
(2,743)
7.7
(2.35)
10,000
(3,048)
8.8
(2.68)
Figure F-6: Lift Loss from Elevation
Barometric Reading
in. (mb)
Lift Loss, Head Ft. (Meters)
29.9
(1,012.5)
NFPA Base Line - 2.38 (0.73mm)
29.7
(1,005.8)
0.2
(0.6)
29.5
(999)
0.5
(0.15)
29.3
(999.2)
0.7
(0.21)
29.1
(985.4)
0.9
(0.27)
28.9
(987.7)
1.1
(0.33)
28.7
(971.9)
1.4
(0.43)
Figure F-6a: Lift Loss from Barometric Reading
Summary of Contents for Silencer AP Series
Page 6: ...Overview 6 Silencer Series Booster Pump p n 029 0020 83 0...
Page 22: ...Introduction 22 Section 2 Introduction Hale Products Inc May 2006 Rev B...
Page 32: ...Accessories Options 32 Section 2a Accessories Hale Products Inc May 2006 Rev B...
Page 66: ...Preventive Maintenance 66 Silencer Series Booster Pump p n 029 0020 83 0...
Page 124: ...Installation 124 Basic Installation Hale Products Inc August 06 Rev B...
Page 143: ...143 Appendix F Cavitation Hale Products Inc Nov 2005 Rev A Cavitation...
Page 144: ...Cavitation 144 Appendix F Cavitation Hale Products Inc Nov 2005 Rev A...
