Ch 12. Relay Pumping Operations Flashcards
The pumper with the largest capacity pump in a relay should be assigned to the water source. This is because the source pumper may have to:
Develop a higher pump discharge pressure in the other pumpers in the relay
What are the limiting factors in a pumper relay system?
The overall capacity is limited by the smallest pump in the relay in the smallest diameter hose used in the relay
What psi intake pressure should drivers/operators maintain as a relay pumper?
20 to 30 psi
What pressure Governor mode should the attack pumper use?
Attack apparatus should be in pressure mode
What pressure governor mode should relay pumpers operate in while relaying water?
Rpm mode
What is a dump line?
A secured hose line or discharge that is used to handle excess water during relay operations
What is a Tender?
A mobile apparatus that has the primary function of supporting another operation. Examples include a water tender that supplies water to pumpers. Some water tenders may carry large diameter hose of more than a mile in length
When considering limitations of the hose while increasing discharge pressure, the driver/operator must remember that:
Discharge pressures must not exceed the pressure at which hose or appliances have been tested
Addidng some additional pumpers into the relay system will allow:
Allow pumpers to operate at lower pressures in maximum flows within the relay operation
When putting a relay into operation, the relay pumpers intake pressure should be maintained at what psi?
20 to 30 psi
What device serves an important role in the safety of a relay operation because of the cumulative effect of pressure increases when changes in flow occur?
Pressure governors
 When relay pumpers are equipped within adjustable intake relief valve, they should be set to _______ psi above the static pressure of the water system to which it is attached.
10 psi
Once a relay is in operation, the driver/operator of the attack pumper should not attempt to correct minor fluctuations as long as the intake pressure does not drop below ______ PSI.
20 psi
How should relay operations be shut down?
Starting at the fire scene
What is the characteristic of an open relay?
Deploys portable folding drop tanks at each intake for pumpers in the relay operation
Why might the open relay method be employed in relay operations?
To provide an alternate water supply system
What type of relay requires no adapters or other appliances to connect intake hose is in the system?
Open relay
What is a benefit of using the open relay method when operating from portable folding drop tanks?
iliminates pressure surges
When relay pumping operation procedures include a predetermined task force, the task force that is dispatched to initiate a relay pumping operation will set up a relay water supply operation:
Independent of the other companies already operating at the same
 What might be true about the type of hose diameters local jurisdictions may use to complete really operations?
A variety of hose diameters might be used
What devices reduce the possibility of damage to the pump and other water supply components that may be caused by water hammer when valves are operated to quickly or intake pressures rise dramatically?
Pressure relief valves
What occurs when intake pressure relief valves are preset to allow a predetermined amount of pressure into the fire pump and incoming pressure exceeds that preset level?
Valves open in dump access pressure/water until water is entering the pump at the correct pressure
What is a type of intake pressure relief valve that is often equipped with a gate valve that allows the water supply to the pump to be shut off?
Screw on intake pressure release valve
What device on an intake pressure relief valve allows air to bleed off as the incoming supply hose is charged?
Bleeder valve
Later arriving pumpers can tie into the relay in boost pressure and volume after it has already started flowing, without interrupting water supply, by using:
In-line relay valves
