Chapter 14 Relay Pumping

Question 1

What are the three options firefighters have when the attack pumper cannot connect directly to a reliable water supply

Answer 1

1. used tank water, and allow fire to burn once empty
2. water shuttle operation
3. water relay operation

Question 2

When are water shuttle operations commonly used

Answer 2

water supply sources more than 1 mile from incident scene or the department involved has insufficient hose to establish a relay

Question 3

what makes relay operation superior to water shuttle operations

Answer 3

relay pumping establishes a constant flow of water to the scene, safety, fuel efficiency.

Question 4

some departments call a two pumper relay

Answer 4

tandem pumping

Question 5

what and NFPA standard requires pumpers to carry at least 800 feet of 2 1/2 inch or larger supply hose

Answer 5

NFPA 1901

Question 6

source, or supply, pumper refers to

Answer 6

the pumper connected to the supply at the beginning of the relay operation

Question 7

relay pumper

Answer 7

sometimes called in-line plumper, pumper in the middle of a relay

Question 8

attack pumper

Answer 8

the pumper in a relay that is at the scene

Question 9

hose tenders

Answer 9

may or may not be equipped with the fire pump, usually carry a mile or more large diameter

Question 10

medium diameter hose

large diameter hose

Answer 10

MDH 2.5”- 3” hose

LDH 3.5”- 12”, ( 3.5”, 4”, 5” are most common)

Question 11

perhaps the most crucial safety device for relay pumping operations

Answer 11

intake pressure relief valve, also called relay relief valve

Question 12

what are the two basic types of intake really valves

Answer 12

supplied by pump manufacturer is integrated part of pump intake and add-on relief valves

Question 13

what should intake relief valves be set at

Answer 13

10 psi above static pressure of the water system

10 psi above the discharge pressure of the previous pump in relay

Question 14

what are the two basic requirements of a relay operation

Answer 14

1. amount of water needed

2. distance between emergency scene and water source

Question 15

incidents that require flows of less than 500 GPM can probably be…

Answer 15

handled by tank water

Question 16

where the four options if the relay flow drops below required levels

Answer 16

1. increase the size of the hose
2. add additional hose lines to the relay
3. increase the pump discharge pressure of relay pumpers
4. increase the number of pumpers in the relay

Question 17

what are the NFPA standards for firehose and firehose maintenance

Answer 17

NFPA 1961

NFPA 1962

Question 18

fire hose should be pumped at pressures that do not exceed ___ of the annual service test pressure

Answer 18

90%

Question 19

what are the two basic designs for relay pumping operations

Answer 19

maximum distance relay method (more common)

constant pressure relay method

Question 20

maximum distance relay method

Answer 20

predetermined volume of water, pumpers are spaced appropriately for the maximum distance they can pump that volume, leaving a minimum 20 PSI residual

Question 21

constant pressure relate method

Answer 21

each pumper in the relay lays out the same type and length of hose, all pumpers pump the same discharge pressure

Question 22

where the advantages constant pressure relay, over maximum distance relay (5)

Answer 22

1. speeds related activation
2. requires no calculation
3. minimizes radio traffic
4. attack pumper can govern fire lines with greater ease
5. operators in the relay only have to guide and adjust pressure to one constant figure ( pump one pressure)

Question 23

when a constant pressure relay is in operation the pump operator should keep correcting their pump discharge pressure to 175 psi until one of the following occurs:

Answer 23

1. intake pressure from the pressurized water source drops below 20psi
2. adjusting throttle does not result in an increase in RPM

Question 24

when performing constant pressure relay, how is pressure adjusted

Answer 24

when increasing the relay pressure the first pressure supply proper is adjusted until desired level is reached. then each successive pumper is similarly adjusted…. decreases and pressure start at the attack pumper then starting at the supply pumper again?

Question 25

what determines the maximum capacity of a relay

Answer 25

the smallest pump and smallest hose line

Question 26

where should the largest capacity pump be placed in a relay

Answer 26

at the water source, especially if drafting

Question 27

relay pump operators should try to maintain the pump intake pressure at between ____, if the intake pressure rises above ___ a dump line valve should be opened

Answer 27

20-30psi | 50psi

Question 28

the attack pumper in a relay operation should set their intake relief valve to____

Answer 28

50-75psi

Question 29

once relay operations are established, the pump operator should take no action as long as intake pressure does not drop below ___ or increase above___. Excessive changes can result in constant varying pressures

Answer 29

10psi | 100psi

Question 30

when shutting down the relay operation start from the____

Answer 30

fire scene to the source

Question 31

4 reasons why the 175 psi figure may be adjusted during a constant pressure relay pumping operation

Answer 31

1. variations in relay pumping spacing 2. severe elevation differences 3. increased required fire flow 4. large diameter hose (requires lower pressure)