5 Water Supply Flashcards
Mobile water supply apparatus generally carry how many gallons of water
1000 to 3500 gallons
Vehicles caring 1000 gallons of water or more of a fire pump are generally referred to as
Tankers
Water carrying apparatus with a standard fire pump and a large water tank used for fire attack or pumping water to pumpers on the fire ground referred to as
Pumper tankers
Vehicles carrying 1000 gallons of water or more without a fire pump but may utilize a small PTO driven pump, specifically designed to carry water to fire are called
Tenders
A method to offload tanker water where pressurized water stream is used to increase the velocity of a larger volume of water that is flowing by gravity through a dump valve
Jet assist
A method to offload tanker water where the tank is pressurized to assist in expelling the water through the dump valve
Pneumatic system
What determines the number of attack lines to be placed in service
The supply of water that can be maintained
Water delivery capacity of a pumper is limited by the
Capacity of the pump, the number of suction intakes, and discharges
Operation of a pumper is limited by
Engine speed and residual pressure
Pump systems must be capable of delivering the following
100% rated capacity at 150 psi.
70% of rated capacity at 200 psi.
50% of rated capacity at 250 psi
Pumpers are rated from which type of water source
At draft from the static water source
True/false pumpers cannot exceed their rated capacity if they are receiving water under positive pressure
False pumpers can exceed capacity when being fed positive pressure water
Which type of valve can be used to receive water from two different supply lines of minimum 2 1/2 inches
Gated suction Siamese valve
Minimum size of discharge outlets to provide the rated capacity of the pump
2 1/2 inches or larger
Usual practice is to install wanted to and a half inch discharge for each what in rated capacity of a pump
One 2 1/2 inch discharge for each 250 gallons per minute of rated capacity
The pump must not be operated about what percent of it’s rated peak speed for any length of time
80%
An increase in engine pump speed, RPM, that does not result in an increase in discharge pressure indicates what
That the pumper has reached it’s pumping capacity or limit of the water supply
Pump operators should maintain a residual pressure of what at all times
20 PSI or more at all times
The residual pressure of a pump should not be allowed to drop below what
10 psi except under extreme conditions
If minimum allowable residual pressure, 10 psi, is reached, the proper procedure is to
Notify the company officer lower discharge pressure never shut down a hose line without knowledge and consent
If action is required to limit the flow of water to increase residual pressure who should determine what actions to be taken to correct the problem
The incident commander
A measure of the reserve capacity of the hydrant is what
Residual pressure
As more water is taken from the hydrant what happens to residual pressure
It drops, The more water taken the less water remains as potential capacity
As flow rate increases what happens to friction loss
Friction loss increases
Hose that is designed to convey water to hose line nozzles, distributor nozzles, master stream appliances, portable hydrants, manifolds, standpipe and sprinkler systems, and pumps used by the fire department.
Attack hose
Hose that is designed for moving water between a pressurized water source and a pump that is supplying attack lines
Supply hose
When and LDH is used to supply attack lines master streams hydrants manifolds standpipes and sprinklers what should be used
A pressure relief device with a maximum setting of 200 psi
The standard hose of the fire service nationally is
2 1/2 inch hose
A 2 1/2 inch supply line should not be used to deliver more than how many gallons per minute
350 gallons per minute
Per 100 feet the friction loss of 2 1/2 inch hose flowing 350 gallons per minute is
25 PSI per 100 feet
Friction loss of 2 1/2 inch hose operating at 250 gallons per minute per hundred feet
15 psi per 100 feet
True/false two, 2 1/2 inch supply lines is preferred over one 2 1/2 inch supply line flowing over 350 gallons per minute
True
What is required of hose to decrease the friction loss as well as the number of his lines needed to move a given amount of water
Increase the diameter of the hose
One 3 inch line is almost as effective as how many 2 1/2 inch lines
Two
What defines an LDH as hose with an inside diameter of 3 1/2 inches or larger
NFPA 1961
4 inch LDH delivers a volume of water approximately equivalent to how many 2 1/2 inch hose
3 1/2, 2 1/2 inch hose lines
5 inch LDH delivers a volume of water approximately equivalent to how many 2 1/2 inch hose lines
Six 2 1/2 inch hose lines
A pumper approaching the fire from a water source should perform which type of lay
Forward lay
If a pumper arrives at the fire first which type of lay should be used from the fire
Reverse lay from the fire to a water source
As a rule, under average conditions, what pressure should a pumper at a hydrant initially begin pumping to a unit at the fire
100 psi
To counteract friction loss of long lays exceeding 1000 feet what type of pumping method should be used
Relay pumping
The maximum capacity of a relay operation is determined by what
The smallest pump capacity and or the smaller supply hose use in the relay
If LDH is not being used to supply lines should be laid initially only if what
They can be laid simultaneously
If LTH is not being used for initial supply line and conditions permit what should be done for supply lines
Lay two supply lines
When initiating a relay pump, what is the process of charging LDH
Pump at water supply charges hose to second pumper, second pump opens intake and charges supply line to third pumper
At the start of the really operation all pumpers in the line should set up to pump what pressure to the pumper at the fire
150 psi
During a relay pump, if additional water is needed, relays capacity is exceeded, what should be done
Another supply line should be late between the operating pumpers
Static pressure is
The pressure in the water pipe with no water is flowing
Residual pressure is
The pressure remaining in a water distribution system while the water is flowing. The residual pressure indicates how much more water is potentially available
Three factors influence the movement of water at fires, they are
Water source, pumper, hose
The four possible water sources at the fire ground are
Watermain systems,
static water sources,
apparatus water tanks,
mobile water supply apparatus.
Flow test of the water main system and components should
Be done by the fire department for the fire department should be part of the process
Areas with what type of water mains are especially vulnerable to water supply problems
Dead and mains and small mains
What type of gauge is used to measure static and residual pressure of intake
Compound gauge
At the beginning of the pump operation the driver reads the compound gauge with the hydrant open and all discharge gates closed, showing which type of pressure
Static
With one attack line charged to the proper discharge pressure of the compound gauge is read again, Showing what
Residual pressure
What gives you the true measurement of available water
The difference between static and residual pressure
When estimating attack lines drop of about 5% from the static pressure to the residual pressure indicates how much more can be delivered by the hydrant
Three equal parts equivalent to the amount being delivered
When estimating attack lines a static to residual drop off 10% indicates how many more equal parts can be supplied from the hydrant
Two more equal parts
A static to residual pressure drop of 20% indicates how many more parts can be delivered from the water main system
One more equal part
In regard to supplying fire attack hose lines from the apparatus water tank and smoke or fire showing situations, is it acceptable
Yes but An uninterrupted supply of water must be established
When operating a take a shuttle as a water supply house should tankers be filled
By pumper stationed at the water source
Pumper intakes in the United States must have
National hose male threads
Quick friction loss calculation for 2 1/2 inch hose by gallons per minute
Take the number of gallons per minute drop the last digit subtract 10. 350, drop zero, subtract 10. 25 psi per 100ft
The proper size hose for a supply line is
Always LDH if available
Name the two main types of mobile water supply apparatus
Tanker and tender
