Preventive measures – Hale Q Series Muscle User Manual
Page 196
Cavitation
196
MUSCLE (Midship) Pumps Installation, Operation, and Maintenance Manual
p/n: 029-0020-63-0
Monitor barometric pressure. NFPA standard sets a baseline of 29.9” Hg. (See
Table G-3: “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 “Strainers” on
page 197.
Preventive Measures
Consider the size of the suction hose. Table G-4: “Hose Size vs. Pump Rating
Capacity” on page 196, lists the NFPA pre-selected hose sizes for each pump-rat-
ing capacity. Using the appropriately sized hose minimizes the occurrence of cav-
itation. An undersized suction hose can lead to cavitation.
Consider the piping within the truck. Suction losses can result from additional suc-
tion piping added to the fire pump during assembly.
Table G-3: Lift Loss from Barometric Reading
Barometric
Reading
in. (mb)
Lift Loss, Head
Ft. (Meters)
29.9
(1,012.5)
NFPA Base Line - 2.38 ft. (0.73 m)
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)
Table G-4: Hose Size vs. Pump Rating Capacity (Sheet 1 of 2)
Hose Diameter
in. (mm)
3”
(75)
4”
(100)
4.5”
(110)
5”
(125)
6”
(150)
Dual
6” (150)
Triple
6” (150)
Flow - gpm (lpm)
Lift Loss gpm (lpm)
250 (1,000)
5.2 (1.6)
350 (1,300)
2.5 (0.7)
500 (2,000)
5.0 (1.5)
3.6 (1.5)
750 (3,000)
11.4 (3.5)
8.0 (3.5)
4.7 (1.4
1.9 (0.6)
1,000 (4,000)
14.5 (4.4)
8.4 (2.6)
3.4 (1.0)
1,250 (5,000)
13.0 (4.0)
5.2 (1.6)
1,500 (6,000)
7.6 (2.3)
1.9 (0.6)
1,750 (7,000)
2.6 (0.8)
2,000 (8,000)
3.4 (13)