Ch 8 Pg 281 Flowmeter - Pg 284 Hyd Calc. Flashcards
The driver must use “blank” to determine the appropriate amount of water to be discharged form hose lines and nozzles?
Hydraulic Calculations
Flow meter
Mechanical device installed in discharge line that sense flow of water, which reads in GPM
What reduces the number of pressure calculations required of driver?
Flowmeters
How do flowmeters measure and display water flow?
In general
When using automatic nozzles with hand lines and/or master stream devices it is advantageous for driver to “blank” and “blank” determine the flow.
Quickly and accurately
The flowmeters relieve you from relying on calculations based on what three areas?
Friction loss, evaluation pressure, and length of hoseline.
Based on NFPA 1901, every discharge equipped with a flowmeter shall also have what?
A pressure gauge
Based on NFPA 1901, flowmeters must display flow in increments of ?
10 GPM or less.
What are the two types of flowmeters?
Paddlewheel
Spring probe
What is a paddlewheel flowmeter?
A small device that extends into the waterway.
Paddlewheel flowmeters reduce what?
Reduces the impediment to water flow and lessens the chance of damage by debris
What is a spring probe flowmeter?
Stainless steel probe detected by pressure on a spring. The greater the flow the more the spring bends. One simple moving part, requires little maintenance.
A flowmeter is good working order should be accurate within how many percent?
Plus or minus 3 %, in other words, based on 100gpm, display should Ben impress or less than 3 gallons.
each discharged equipped with a flowmeter must have a digital readout display mounted with in how many inches of the control valve for that discharge
6inches
If there is a pressure gauge mounted at the 6 inch location, then the flowmeter must be mounted with in how many inches adjacent to the pressure gauge?
2 inches
What additional information do monitoring devices offer?
- Flow from any specific discharge
- Total “real time” water flow through the pump
- total water flowed through the pump for the duration of the incident
- amount of foam being flowed
The driver may use flowmeters to identify what?
Water flow issues such as kinks, partially closed valves, and burst lines. All show decreases in pressure
Intake pressure should not be allowed to drop below what PSI
20 psi
With the exception of attack pumpers, What should pumps with electronic pressure governors involved in relay pumping operate in?
RPM
Standpipes: when equipped with flowmeters, the number and types of nozzles on lines operating on a standpipes you can be factored by?
Adding the flow rate for each nozzle together and pumping the volume that matches that rate.
When operations on a standpipe, the driver must monitor the status of each line to determine what?
Which attach lines are flowing
During standpipe operations, when a line is shut down, what must you do?
Lower the pressure accordingly, or the standpipe system will try to flow excess through the remaining hose lines.
True or false, the pressure governor in RPM mode with compensate for a shut down line, when multiple lines are in use during standpipe ops?
False, RPM mode will not automatically compensate for reduced flow, but PSI mode will.
Drivers must consider what when a hose line or standpipe is charged?
That there is no flow through the system until until you open the nozzle
Drivers must rely on what three things to set pressures that are relatively close to what is required for water discharge?
Experience, training, and operating guidelines
