Chapter 12 Flashcards
What is the formula for relay distance?
P = R/D +1
P= total number of pumpers needed
R= relay distance
D= distance from tables 12.1 or 12.1b
When relaying long distances, what should pumpers do with hose lays?
Try to make them equalized as possible
A relay pumping operation should begin with what pumper?
The largest capacity pumper working from the water source
All personnel involved in the relay operation must understand?
That the overall capacity of the system is determined by the smallest pump and the smallest diameter of hose used in the relay.
The relay pumper should be waiting for water and doing what action?
With a dump line or discharge open and the pump out of gear. When the source or relay pumpers are ready the discharge supply the hose line on the source pumper is opened while the valve on the dump line is closed in a coordinated action. This is done to force air out of the relay pumpers pump. Engage pump after steady flow of water
Relay pumpers with adjustable intake relief valves should be set to what psi above the static pressure of the water system or what psi above the discharge pressure of the previous pumper in the relay?
10 psi above static pressure of the water system, or 10 psi above the discharge pressure of the previous pumper in the relay
Attack pumpers with adjustable intake relief valves should be set to?
Set Between 50 to 75 psi to establish a stable operating condition
When the need for relay pumping has ended, the operation should be discontinued from what point?
It should be discontinued from the fire scene
What is the open relay method?
Consist of deploying portable folding drop tanks at each intake for pumpers in the relay operation.
Driver operators should refer to what NFPA standard for the placement of relief valves?
Nfpa 1962
Inline relay valves are used for what typically?
Placed along the length of a supply hose to permit pumpers to connect to the valve to boost pressure/volume in the hose. These allow for uninterrupted water supply.
