Relay Pumping Operations
Relay
Pumping
Operations
Instructors
Copy
INITIAL 12/99
FOR MORE INFORMATION CONTACT COURSE COORDINATOR AT
MISSISSIPPI FIRE ACADEMY
#1 FIRE ACADEMY USA
JACKSON, MS 39208
(601) 932-2444
NFPA 1001 - I&II FIREFIGHTER
IG 1
CERTIFICATION DIVISION
Mississippi Fire Academy
Relay Pumping Operations
Subject: Relay Pumping Operations
Time: 45 minutes
Objectives:
3-2.2/6-2.2 Pump a supply line of 2 2" or larger, given a relay pumping evolution, the length
and size of the line, desired flow and intake pressure, so that the proper pressure and flow are
provided to the next pumper in the relay.
(a) Requisite Knowledge: Safe operation of the pump
(b). Requisite Skills: The ability to position a fire department pumper to operate
at a afire hydrant and at a static water source, power transfer from vehicle
engine to pump, draft, operate pumper pressure control systems, operate the
volume/pressure transfer valve(multistage pumps only), operate
auxiliary cooling systems, make the transition between internal and
external water sources.
NFPA 1001 - I&II FIREFIGHTER
IG 2
CERTIFICATION DIVISION
Mississippi Fire Academy
Relay Pumping Operations
Outline
I. Relay Apparatus and Equipment
II. Relay Pumping operational Considerations
III. Types of Relay Pumping Operations
A. Maximum Distance Relay Methods
B. Constant Pressure
IV. General Guidelines for Relay Operations
A. Putting the Relay into Operations
B. Operating the Relay
C. Shutting Down the Relay
NFPA 1001 - I&II FIREFIGHTER
IG 3
CERTIFICATION DIVISION
Mississippi Fire Academy
Relay Pumping Operations
Introduction
In some fire situations, the source of water may be a considerable distance
from the fire. When faced with this, pumping operations must relay the
water to the fire scene. Relay operations use the pumper at the water
source to pump water under pressure through hoselines to the next
pumper. Components of a relay operation, factors that influence the relay,
and various methods for establishing a relay operation will be discussed in
this chapter.
Slide 4 I. Relay Apparatus and Equipment
Various pieces of equipment are used. Standard fire apparatus are used
for pumping
A. Explanation of terms
1. Source pumper- connected to the water source
2. Relay pumper (in-line pumper)- connected within the
relay and receives water
3. Attack pumper- located at the fire and receives water
4. Hose tenders
a. May or may not have a pump
b. Usually carry large amounts of hose (LDH),
tools and appliances
Slide 5 B. Variety of appliances may be used
1. Intake pressure relief valves- (2 types)
a. Supplied by pump manufacturer
b. Add-on device
Both should be preset within 10 psi of static pressure or
above the discharge pressure of previous pumper
c. Bleeder valves- allows air to e bled off
Slide 6 II. Relay Pumping Operational Considerations
Relay operations are based on:
Χ Amount of water
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IG 4
CERTIFICATION DIVISION
Mississippi Fire Academy
Relay Pumping Operations
Χ Distance from emergency scene to the water source
A. Amount of water
1. Relay may supply total water needed
2. Relay may supplement
B. Distance
1. The longer the distance, the longer the hose lay
a. More friction loss
b. Size of hose affects flow
c. Number of pumpers needed
2. To increase amount of water
a. Increase hose size or number of hoses
Slide 7 III. Types of Relay Pumping Operations
Two determining factors:
Slide 8 A. Maximum Distance Relay Method
Involves flowing a predetermined volume of water for the
maximum distance it can be pumped.
1. Note Table 13.1 to determine number of pumpers
needed.
Slide 9 B. Constant Pressure Relay Method
Used constant pressure by establishing maximum flow
Χ Speeds relay activation
Χ Requires no complicated calculations
Χ Radio traffic and confusion is reduced
Χ The attack operator governs with greater ease
Χ Operators only have to adjust to one constant
pressure
Slide 10 1. Forming the Constant Pressure Relay
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CERTIFICATION DIVISION
Mississippi Fire Academy
Relay Pumping Operations
a. Position the attack pumper
b. Place largest pumper at the source
c. Lay out hose
d. Connect all hose to all pumpers in relay
e. All D/O open discharges except source
f. Source pumper develops 175 psi
Slide 11 g. D/O closes discharges slowly & throttle to 175
psi
h. Set relief valve or governor
2. Keep pressure until
a. Intake pressure drops below 20 psi
b. Throttling does not increase rpm
3. Constant pressure can be modified for:
a. Pumper spacing
b. Elevation differences
c. Increases in needed flow
d. LDH hose
Slide 12 IV. General Guidelines for Relay Operations
A. Putting the Relay into Operation
1. Always begins with the source pumper- largest pumper
2. When water is established, use a dump line until relay is
ready.
a. When discharge begins, slowly close dump line
and keep residual below 50 psi.
3. In receiving water, relay pumpers should maintain 20-
30 psi residual.
a. If residual is greater than 50 psi, open dump line
b. As discharge increases, residual decreases
Slide 13 B. Operating the Relay
1. Once in operation, set pressure control device
a. Operate auxiliary cooler for extended operations
NFPA 1001 - I&II FIREFIGHTER
IG 6
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Mississippi Fire Academy
Relay Pumping Operations
C. Shutting Down the Relay
NFPA 1001 - I&II FIREFIGHTER
IG 7
CERTIFICATION DIVISION
Mississippi Fire Academy
