Chapter 10 - Operating Fire Pumps

What are the steps for engaging a midship transfer pump?
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What are the steps for engaging a midship transfer pump?
1.) Bring apparatus to a full stop
2.) Shift transmission to neutral
3.) Set apparatus parking brake
4.) Operate the pump shift control to transfer power from the drive axle to the pump drive.
5.) Shift the transmission into the appropriate gear for pumping
When performing pump operations from the apparatus water tank, assuming the pump is full of water, what will the master pressure gauge do?
If the pump is normally full of water, it should begin to rise as soon as the rpm is increased.
If the pump has been drained of water, what are the steps for forcing air out of the pump?
The air has to be forced out of the pump by the water as it enters before discharge pressure can build;
AT LEAST ONE DISCHARGE VALVE OR THE TANK FILL LINE MUST BE OPENED BEFORE AIR CAN ESCAPE and the pump can fill with water.
Per Chapter 10, what is the distance SOME drivers will open the tank fill valve to recirculate water?
The distance of their thumb to the panel with their hand on the valve control
As discharge flow increases, incoming pressure from a supply source will do what?
It will drop due to friction loss
What are two key considerations when making a forward lay?
Distance from hydrant to the fire
Amount of supply hose carried
Describe the use and purpose of 4 way hydrant valves
1.) They allow the original supply line to be immediately charged
2.) The valve has a 2nd discharge, usually 4.5" to 5", equipped with a shut-off valve.
3.) A second pumper may be connected without interrupting flow to the first
How should you load hose for a reverse lay?
With the male couplings set to come out first (when using threaded couplings)
What is the hose configuration for a forward lay (when anticipating hooking up for big water)
By using a double female at the hydrant and a double male at the pump.
What is the most direct method for supplementing hydrant pressure or performing drafting operations?
Reverse lay
What prevents water from entering the tank under pressure?Check valves in the tank to pump line. NOTE: Rigs before 1991 may not have this featureTrue or False: D/O should close the tank to pump valve after transitioning to an external water supplyTruePercentage Method Equation[(Static - Residual) x 100] / Static or 100(S-R) / SFirst Digit Method1.) S-R = X 2.) First Digit (Y) of Static x 1, 2, or 3 3.) X </= Yx1 - 3 more lines of equal GPM 4.) X </= Yx2 - 2 more lines of equal GPM 5.) X </= Yx3 - 1 more line of equal GPMWhat are the assumed flow rates for the squaring the lines method?1.5" Hose - 125 gpm 1.75" Hose - 175 gpm 2" - 200 gpm 2.5" - 250 gpmSquaring the Lines Method1.) S-R = X 2.) Multiplication Factor = (Number of Lines)Squared 3.) Resultant Pressure Drop = MF x (X) 4.) S - RP > 20 psi to determine whether or not you have enough water.Pressure Differential (partial vacuum)The effect of altering the atmospheric pressure within a confined space by mechanical meansWhat happens to the environment when air is exhausted from within the space?A low pressure environment is created and replacement air will be drawn inWhat happens when air is blown into a definite space?A high pressure environment is created and air will be moved outsideWhat is the atmospheric pressure at sea level?14.7 psi or 30" HgWhen drafting, friction loss is proportional to what?The amount of water moving through the hard suctionPressure decreases by how much psi for every 1,000 of elevation gain?.5 psiMost pumps are able to develop a vacuum capacity of approximately ______ Hg22" HgDefinition: CavitationWater being discharged faster than it is coming into the pumpWhat are some factors affecting the point at which cavitation can begin?1.) Temperature 2.) Height of lift 3.) Volume of waterWhat are some indicators of cavitation?1.) Pressure gauge fluctuations 2.) Hose stream pulsation / popping / sputtering sound 3.) Gravel like noise within the pumpWhat is the SUREST indication of pump cavitation?A lack of reaction on pressure gauge to a throttle increaseWhat depth of water is required for a pump to approach is rated capacity using a traditional strainer while drafting?There must be 24" in all directions from the strainerThe use of a low level strainer allows water to be effectively drafted from what depths?2"What is the ideal water temperature while drafting?Between 35 degrees F and 90 degrees FWhat happens to elevation pressure as the amount of life increases?Elevation pressure increasesWhat happens to the capacity of the pump as the amount of lift increases?The capacity of the pump decreasesAll pumps meeting NFPA and ULI requirements are rated to pump their capacities at _______' of lift10'A pumper in good working order can lift water a maximum of ______'25'To create an effective fire stream, a lift no greater than ______' is recommended20'Working at 20' of lift, a pump operates at approximately what percentage of its rated capacity?60%When drafting while using a two stage pump, the transfer valve must be in what position?Parallel (volume)What is a consequence of attempting to draft while in Series?The pump may trap airWhat is the most effective engine speed when priming?Between 1,000rpm and 1,200rpmWhat is the ideal engine speed with an apparatus featuring a vacuum type pump?The lowest RPM possible without causing an engine stallWhat should the reading on the intake gauge indicate during a drafting operation?1" of Hg for every 1' of liftHow is vacuum (lift) measured?The height of the water surface to the eye of the impellerHow long does a priming action typically take?0:10 to 0:15 NOTE: It could take up to 0:30 when up to 20' of intake is used to lift a maximum of 10'What is the most common cause of an inability to prime?An air leakWhat is the most common cause of an air leak?An open drain or valve - SPECIFICALLY on the intake side of the pumpWhat is one of the primary ways of preventing a loss of prime or overheating the pump/engine?Recirculating a booster line into the static water sourceFluctuations in discharge pressure with a corresponding loss of vacuum on the intake gauge - What does this indicate? What is the solution?An air leak on the intake side of the pump Solution: Recheck couplingsWhirlpool allowing air to enter the pump. What's the problem? What's the solution?Problem: There's not enough water above the strainer Solution: Put at beach ball on top of the whirlpoolAir leakage due to defective pump packing: What's the problem? What's the solution?Problem: If onboard water tank is empty, tank-to-pump line may be source of the leak Additionally: This is likely to occur when an excessive amount of water leakage from the packing in a steady stream instead of just drippingGradual increase in the vacuum with no change in flow rate? What's the problem?This is an indication that a blockage is developingWhat should you do if you experience a gradual decrease in discharge pressure?Decrease the engine RPM until the pressure drops and immediately check for blockages in the strainerWhen is a pump most likely to experience a blockage?When the pump is operating at a high rate of dischargeTo support sprinkler systems when using a multistage pump, what position should the transfer valve be set in?Parallel (volume)According to IFSTA, a general guideline is to discharge what psi into the FDC?150 psiAccording to IFSTA, pressure reducing valves are installed at standpipes to reduce the amount of pressure at that discharge to what psi?Usually 100 psiWhen performing pump operations from the apparatus water tank, what position should the transfer valve be set to?Series (skill-sheet p. 392) NOTE: IFSTA recommends Parallel for priming and standpipe operations.What is the appropriate sized hose for a 1.5" FDC?1.75" HoseWhat is the appropriate size hose for a 2.5" FDC?At least 1x 3" Hose or 2x 2.5" HoseWhen should you check static pressure when operating from a pressurized water source?After the pump is full of water and the pressure in the system has stabilized.What does IFSTA recommend when making a transition from tank water to a pressurized water source while lines are flowing?1.) Open the intake valve while adjusting the throttle to avoid a pressure surge (we can't do this on our rigs) 2.) Switch to RPM mode on the pressure governor and ensure air is bled from the supply line before opening the intake, then switch back to Pressure