Hale MG - Manual (Page 53)

Muscle Pumps
3-10
TABLE 3-4.
SUGGESTED NOZZLE SIZE (INCHES)
PUMP RATING FULL CAPACITY 70% CAPACITY 50% CAPACITY
750 1-3/4 1-3/8 1-1/4
1000 2 1-5/8 1-3/8
1250 (2) 1-1/2 or 2-1/4 1-7/8 1-1/2
1500 (2) 1-3/4 or 2-1/4 2 1-3/4
1750 (2) 2 (2) 1-1/2 or 2-1/4 1-7/8
2000 (2) 2 (2) 1-3/4 or 2-1/4 2
2250 (2) 2-1/4 (2) 1-3/4 or 2-1/4 2
The following general guidelines should be used
when testing the apparatus.
For 750 GPM (2839 LPM) test, two 2-1/2-inch
lines should be laid from the pumper to the nozzle.
For 1000 GPM (3785 LPM) test, three lines are
required, and for the 1250 (4731 LPM) and 1500
GPM (5677 LPM) tests, four or more lines are
required between the pumper and the nozzle. For
1750 (6624 LPM) and 2000 GPM (7570 LPM)
tests four or more hose lines and two nozzles are
required. For testing a 2250 GPM (8516 LPM)
pumper up to six hose lines into two separate
nozzles should be used.
Because deluge guns are not always available,
other hose layouts may be used, such as one, 2 1/2-
inch line to a 1-3/8-inch nozzle for 500 GPM
(1892 LPM). Generally, the nozzle used on one, 2
1/2-inch line should not be larger than 1 1/2 inches
for accuracy in measuring GPM (LPM). Another
alternative when a deluge gun is not available
consists of a 1 1/4 inch nozzle on one and a 1 1/2
inch nozzle on the other to pass 1000 GPM (3785
LPM). The sum of the flow from both nozzles is
the GPM (LPM) delivered by the pump. For good
pilot gauge accuracy, the nozzle pressures should
be between 30 and 85 PSIG (2.1 and 5.8 BAR).
Because NFPA standards specify both GPM
(LPM) and pressure, it is usually necessary to
restrict the flow somewhat to build up the pump
pressure. In normal pumping, this restriction would
be caused by the friction loss in the lines.
However, depending on line loss alone would
require a large amount of hose for some tests. For
example, testing a 500 GPM (1892 LPM) Class A
pumper at 250 GPM (946 LPM) and 250 PSI (17.2 BAR) requires 72-PSI (5 BAR) nozzle pressure on a
one-inch tip. To reduce the pressure from 250 PSI
(17.2 BAR) at the pump to 72 PSI (5 BAR) at the
nozzle would require approximately 1100 feet of 2
1/2-inch hose. Therefore, it is common practice to
use 50 to 100 feet of hose and gate the discharge
valves as required.
Performance Testing
Note that the NFPA standards require a 10 percent
reserve in pressure at the capacity run when the
apparatus is delivered.
1. Check the relief valve according to the Relief
Valve Testing procedure under Weekly
Maintenance.
2. Perform steps 1 and 2 of the Post Operation
Maintenance procedures in this section.
3. Run the standard pump test in accordance with
NFPA standards to check pump performance.
4. Run the engine for 20 to 30 min utes to
stabilize the engine temperature. Then run the
pump for 20 minutes at capacity, 10 minutes at
70 percent capacity, and 10 minutes at 50
percent capacity.
5. If the apparatus does not reach performance
levels, refer to the Hale diagnostic/service
chart (Section 4).
6. Compare the results of this test to those from
when the apparatus was delivered. It maybe
that the apparatus did not show the 10
percent reserve at delivery. If the apparatus