Tpm operation from a hydrant, Draft limiting factors, Table 3-3: baseline nfpa rating – Hale SMR User Manual
Page 40: Pumping from draft, Table 3-3: baseline nfpa rating (additional loses), Caution
Operating Procedures
3-6
Stainless Max Series Pumps
TPM Operation from a Hydrant
When operating from a positive inlet pressure, during some opera-
tional conditions, it may be necessary to adjust the TPM Relief
Valve to a point where water is dumping to the ground. The internal
relief valve will always open first, and if it cannot handle the pres-
sure rise, the external relief valve will dump water on the ground.
When the internal relief valve opens, the panel light turns ON, and
when the external dump valve opens, the pilot light on the panel
flashes.
Draft Limiting Factors
See Table 3-3: “Baseline
NFPA Rating (Additional
Loses).”
The effect of raised
water temperatures
when pumping from a
positive pressure source
(i.e., a hydrant) is negli-
gible on fire pump
performance. However,
when pumping from
draft, elevated water tempera-
ture does have a limiting effect.
Water temperature above 95
°
F (35
°
C) causes a noticeable decrease
in lift when drafting. Another factor that can limit lift when drafting is
barometric pressures below 29 In. of Hg.
It is important to be aware of environmental conditions when
drafting.
Pumping from Draft
1. Get as close to the water source as possible. The pump can
draw 100% of its rated capacity with less than a 10 foot (3.05
meters) vertical lift. As the lift increases to above 10 feet, the
pump capacity is reduced.
CAUTION!
REFER TO DEPARTMENT PROCEDURES FOR SETTING WHEEL
CHOCKS AND LAYING OUT SUCTION AND DISCHARGE HOSES. ALL
VALVES, DRAIN COCKS, AND CAPS SHOULD BE CLOSED.
Water Temperature
F° (C°)
Lift Loss
Head Ft. (mm)
Table 3-3: Baseline NFPA Rating
(Additional Loses)
°
0
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°
6
1
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e
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A
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2
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3
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6
.
7
(
°
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7
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6
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2
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5
1
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°
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°
2
3
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8
2
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°
8
3
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7
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2
.
3
4
(
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°
3
4
(
5
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.
3
6
(