3 Pump Equipment Centrifugal Pump Pressure Relief Valve/Governor Intake Relief ValveTransfer ValvePositive Displacement PrimersManual Pump ShiftGaugesAuxiliary CoolerThe pump equipment covered in this class will include the following;Centifugal pumpPressure relief valve/governorIntake relief valveTransfer valvePositive displacement primersManual pump shiftGaugesAuxiliary cooler
4 Centrifugal Pump Non-positive displacement pump Three factors influence pump discharge pressure1) Incoming pressure, 2) Speed of the impeller, and 3) The amount of water being dischargedSingle or multi-stageNOT self-primingCavitationThe centrifugal pump is a non-positive displacement pump, which means that it does not pump a definite amount of water with each revolution.Three factors influence pump discharge pressure;1) the amount of water being discharged2) the speed at which the impeller is turning3) the pressure that the water has when it enters the pumpThe centrifugal pump can be single or multi-stageA single stage pump uses a single impeller to deliver water with pressure capabilitiesA milti-stage pump utilizes two or more impellers and a transfer valve to allow the pump to create pressure or volumeWhen in the pressure mode, the impellers pump in a seriesWhen in the volume mode, the impellers pump in parallelA centrifugal pump cannot pump air, therefore cannot be self priming
5 Pressure Relief Valve/Governor Most common devicesSet while discharging at operating pressureSet for highest operating pressurePressure relief valve - diverts waterPressure governor - controls rpmThe most common devices used are the pressure relief valve and the pressure governor.These devices should be set while all the lines are discharging water at their proper operating pressures.The line with the highest operating pressure determines what pressure the device will be set at.The pressure relief valve relieves excess pressure by allowing water to be diverted from the pump discharge to the pump intake.The pressure governor controls excess pressure by adjusting the speed of the engine.If pressure increases, the engine rpm will decrease to maintain proper pressure.If pressure decreases, the engine rpm will increase to maintain proper pressure.
6 Intake Relief Valve Also known as dump valve Protects pump from water hammer and excessive intake pressurePossibly capped during high pressure operationsPiston intake relief valveCommonly referred to as a dump valve, it is designed to protect the pump from incoming water hammer or excessive intake pressure.Valves have adjustable settings, on some apparatus it is not easily accessible.Normally, should be adjusted to slightly higher than normal hydrant pressure.If pumping in a high pressure relay, such as high rise fires, the high pressure pumper will possibly have to cap these valves.Piston intakes have an additional relief valve which have adjustable settings.In cases of high pressure operations, these intakes may have to be removed if the setting cannot be adjusted.
7 Transfer Valve Multi-stage pump only Pressure (series) vs. Volume (parallel)Most operations in pressure mode50% ruleChange 50 psi net pump pressureFound on multi-stage pumps, is required to switch from pressure mode to volume mode.Most operations will be in the pressure mode.If the volume of water being pumped exceeds fifty percent of the pumpers rated capacity, it should be placed in the volume setting.Changing from one setting to another should be done at no more than 50 psi net pump pressure.If lines are already in operation when the change over is to take place, the incident commander must be notified, coordination with attack crews is essential.
8 Positive Displacement Primers Required for draftingMost common - rotary vaneOperate for no more than 45 secondsPriming oilEnvironmentally safe primersSince centrifugal pumps cannot pump air, positive displacement primers are required for drafting.The most common is the rotary vane primer, which is driven by an electrical motor.The primer should not be operated for more than 45 seconds at a time.While operating, most primers use an oil supply to fill gaps between the vanes and the pump casing. The oil is expelled with the air and water under the apparatus.Newer pumpers are equipped with environmentally safe primers which do not use oil. These primers are impregnated with a silicon-type material, and will not have a reservoir.
9 Manual Pump Shift Provides back-up Usually located on pump panel Often require two persons to operateBack-up throttle may have to be usedExercise manual shift oftenMost modern apparatus rely on electrical or air actuated pump shifts. Problems occasionally occur with these and the manual shift provides a back-up.The manual pump shift is usually found on the pump panel and often requires two persons to operate. When it is necessary to use the manual pump shift, the back-up throttle may have to be used.Exercise the manual pump shift often to assure working condition.
10 Gauges Compound gauge Master intake gauge (compound) Master discharge gaugeIndividual discharge gaugeEngine gaugesThe various gauges found on a pumping apparatus are as follows;Compound gauge - Capable of reading both positive and negative pressure readings. Usually psi for positive pressure and 0-30 inches of mercury for negative pressure.Master intake gauge - Connected to the intake side of the pump, when connected to a positive pressure source, both static and residual pressures can be obtained.Master discharge gauge - Connected to the discharge side of the pump. It measures the total discharge pressure of the water as it leaves the pump.Individual discharge gauge - One gauge per outlet, measures pump discharge pressure for the specific outlet.Engine gauges - Tachometer, oil pressure, and water temperature gauge. Monitor these gauges closely, if a reading outside of the normal operating range is obtained, correct the problem. If unable to correct the problem, shut down the pumping operation as soon as possible.
11 Auxiliary Cooler Allows water from pump to cool engine Use when temperature exceeds normal levelClose when temperature returns to normalKeep in closed positionThis valve allows water from the pump to be diverted to decrease the engine coolant temperature. The water runs through a separate set of coils, without mixing with the fluid in the radiator, and then returns to the pump.If the temperature exceeds normal recommendations, or a warning light/buzzer is activated, the engine must be cooled immediately. This is accomplished by opening the auxiliary cooler valve located on the pump panel.Once the temperature has returned to normal, the valve should be closed. If the device has to be used, notify the incident commander and mechanic.This valve should be carried in the closed position during normal operations.
12 Valves Main intake valve (suction)-keystone, piston, MIV Auxiliary intake valve ( 2 ½ )Tank-to-pump valveTank fill valveDischarge valvesPump drain valveDischarge drain valveIntake drain valveMain intake valve - Known as keystone, piston intake or MIV. Located on both sides of the pumper. On apparatus equipped with rear intakes, the rear intake should be used only after both side intakes have been utilized.Auxiliary intake valve - a 2 1/2” connection, usually on the engineer’s side of the apparatus. Can use a 2 1/2” male - 4” female adapter for connection with large diameter hose.Tank-to-pump valve - A clappered valve located on the intake side of the pump, allows water from the booster tank to be discharged through the pump when in the open position. Once another water source is obtained, close the tank to pump valve.Tank fill valve - Located on the intake side of the pump, allows the booster tank to be filled from a supplied water source. Should be opened as soon as another water source is connected to the pumper. Also can be “cracked” open to act as a recirculating valve in order to cool the pump.Individual discharge valves - Used to control the flow of water from a specific discharge. These valves can be “gated back” to provide different pressures. Most can be locked in place by turning the handle a quarter turn.Fire pump drain valve - used to drain the pump and plumbingIndividual drain valve - Drains individual dischargesIntake drain valve - Relieves pressure between the hydrant and intake.
14 Booster Tank Sizes Tank-to-pump valve Use only one handline Obtaining positive sourceRefill as soon as possibleThe most common size in the fleet is 500 gallons, some apparatus such as the 88 Seagrave and 93 Pierce have 750 gallon tanks.The tank-to-pump valve should be left in the open position.When using the booster tank, only one handline should be used.Once a positive pressure source is obtained, an increase in pump pressure will probably occur and an adjustment will have to be made to the discharge pressure.The booster tank should be refilled as soon as possible.
15 Hydrant Operations Two types of hydrants Steamer should face street Blue reflectors assist in locatingColor coded to main sizeMUD Districts may not color codePrivate hydrants - Apartments, BusinessesThere are two types of fire hydrants, wet-barrel and dry barrel.The dry barrel is the most common type of hydrant in use today and is primarily used in areas where freezing temperatures may be encountered.The largest opening should be facing the street and be at least 15” above grade.Blue reflectors may be present in the middle of the street to assist in locating hydrants at night.Hydrants are color coded to main size. The codes are as follows;Red 4”Yellow 6”White 8”Green 10”-20”Orange 24”-60”Orange bonnet and caps 100 psi and 36”-90”Hydrants located in municipal utility districts are not required to be color coded.
16 Water System Consumption Peak use hoursMorning - residential areasMid day - downtown areasEvening - residential areasMay contact Water Department to divert water to fire areaLow water pressure may be experienced due to high consumption on the domestic side of the system. It may become necessary to contact the water department to have water diverted to the fire area.
17 Drafting Primary source for rural fire protection Portable water suppliesStatic water suppliesStatic and portable water supplies are usually the primary source for rural fire protection. Static water supplies are lakes, ponds, rivers, cisterns, retention ponds and pools. Portable water supplies would include Tankers.
19 Theory of Pressure Force: measure of weight Pressure: measure of force per unit area
20 Pressure and FluidsPressure acts on fluids according to six basic principlesFluid pressure is perpendicular to any surface on which it acts.Fluid pressure at a point in a fluid at rest is of the same intensity in all directions.Pressure applied to a confined fluid from without is transmitted equally in all directions.The pressure of a liquid in an open vessel is proportional to its depth.The pressure of a liquid in an open vessel is proportional to the density of the liquid.The pressure of a liquid on the bottom of a vessel is independent of the shape of the vessel.
21 Hydraulic Calculations Engine Pressure = nozzle pressure + friction loss in the hose + friction loss in appliances + pressure due to elevationNozzle Pressure - The amount of pressure required at the nozzle to produce an effective fire stream.
23 Friction LossThe part of the total pressure lost while forcing water through pipe, fire hose, fittings, adapters, and appliances. The basis for fire hose friction loss calculations are the size of the hose, the amount of water flowing, the length of the hose lay, the age of the hose, and the condition of the lining.These factors give rise to the formula for computing friction loss: FL = C · Q · L
24 FL = C · Q · L FL = friction loss in psi C = coefficient ( constant ) Q = flow rate in GPM/100L = hose length in feet/100FL = friction loss in psiC = coefficientQ = flow rate in GPM/100L = hose length in feet/100
26 ExampleIf 200 gpm is flowing from a nozzle, what is the friction loss in 200 ft. of 2½” hose?FL = C · Q · LC = 2Q = gpm/100 = 200/100 = 2L = length/100 = 200/100 = 2FL = (2) (2) (2) = (2) (4) (2) = 16 psi
27 GPM FormulaIt is possible to determine water flow from any solid stream nozzle when the nozzle pressure and tip diameters are known. The following formula is used to determine the GPM flow of solid stream nozzles: GPM = 29.7 ·d2 ·NP29.7 is a constantd - diameter of the tip, measured in inchesNP - nozzle pressure in psi (square root )
28 GPM = 29.7 ·d2 ·NP GPM= Discharge in gallons per minute 29.7 = A constantd = Diameter of the tip (inches)NP = Nozzle pressure in psi (square root)29.7 is a constantd - diameter of the tip, measured in inchesNP - Nozzle pressure in psi ( square root )
29 Example Determine the water flow from a 2” tip operating at 80 psi. GPM = (29.7) (d)2 (NP)= (29.7) (2)2 (80) (use 81)= (29.7) (4) (9)= (118.8) (9)= GPM (1070)
36 ExampleWhat is the engine pressure for 200 ft. of 1¾” hose flowing 200 gpm, with a low pressure fog nozzle, on the third floor?EP = NP + FL + Appliance + ElevationEP =EP = 215 psi
37 Wyed Hoselines Complex pumping situation Common with apartment lay Same size and typeDifferent sizeCommunication with crewsWhen pumping into hoselines of differing size, engine pressure will have to be set to supply the line with the greatest friction loss and nozzle pressure. Other lines operating from the apartment lay will have to be gated back by the attack crew.
38 Pressure vs. Volume Common misconception Maximum capacity at draft Maximum capacity with positive pressureNet pump pressure
39 Calculating Additional Water Available Static pressureResidual pressurePercentage drop: static -residualFormulaPercentage Drop = (Static - Residual) (100)Static
40 Water Available Table Percent Decrease Water Available % x amount% x amount% same amountOver 25% less than being delivered
42 Multiple Discharges Different Pressures Different Friction Loss CalculationsGating Back DischargesSet Pressure Relief Device/Governor
43 Master Streams Most Common - Deck Gun, Ladder Pipe Nozzle Tips Flowing GPMSolid Bore - 80 psi Nozzle PressureFog Nozzle psi Nozzle Pressure25 psi Friction Loss
44 Standpipes and Sprinklers Usually have a 2 ½” connectionHook up with 3” high pressure hose or 4” hose with adapterReverse layDO NOT PUMP UNLESS ORDERED
45 Non-PRV Systems Standpipe: Sprinkler: Fog Nozzle: 150 psi + 5 psi per floorSolid Stream 65 psi + 5 psi per floorSprinkler:150 psi + 5 psi per floorElevation loss is calculated to the fire floor
46 PRV Systems Pump the designed pressure if known If the designed system pressure is unknown:100 psi + 6 psi per floor to the top floor of the zoneWhen pumping into a PRV system, the standpipe outlet pressure cannot be raised above its designed pressure
47 Relay PumpingNecessary when the required GPM flow of the attack pumper cannot be met because of friction loss in the supply linePump pressure is based on GPM needed and distance between pumpers20-50 psi residual in addition to friction lossRelay initiated by pumper at water source
48 Relay PumpingIntermediate pumpers - close pump to tank valve, open 2½” discharge until water discharges, close discharge, place in pump gear and open supply to next pumperDischarge pressures should not exceed 200 psi, if pressure required to supply water is greater than 200 psi, another pumper or additional lines are needed
49 Relay Pumping Relay is designed to deliver volume not pressure Relay is terminated by attack pumper by decreasing pressure, followed by next pumper in relay, etc.
50 Foam Operations Portable Eductors Do not start foam operations unless incident can be terminated with resources availablePortable eductors require 200 eductorEmulsifiers can be 1/2 or 1%Nozzle setting must 95 gpmApparatus will carry gallon containers of foam and gallon containers of cold clean
51 Foam OperationsPortable eductors must be flushed with clean water to prevent gumming of the pick-up tube. Flush the entire hoseline for approximately 5 minutes.Rotate the proportioning valve while flushingMaximum length from eductor to nozzle is 300 ft of 1 3/4” hose or a combination of /4” and 2 1/2” hose not exceeding 450 ft
52 Permanently Mounted Eductor Similar to portable eductorRequire same eductorMaximum hose length from eductor to nozzle ft of 1 3/4” hose or a combination of 1 3/4” and 2 1/2” hose not exceeding 450 ftProportioning valve located on pump panel
53 Direct Injection Foam System Uses a pump to inject the emulsifier/foam into a discharge pipe that connects the fire pump and designated foam dischargesControlled by electronic keypadTwo tanks - 40 gallons foam, 10 gallons emulsifierSystem is self adjusting, regulated by flow meter
54 Direct Injection Foam System Intake pressure kept below 50 psiMinimum pump pressure is intake pressure plus 100 psiMaximum pump pressure 250 psiSet engine pressure according to hoselay and nozzleFoam and emulsifier flows only through designated discharges
55 Direct Injection Foam System Can flow water through non-foam discharges simultaneouslyTo flush system, decrease pump pressure to 100 psi and place toggle switch in flush position - flush system for 20 secondsTurn foam system off and flush hoseline for 5 minutes
56 Drafting 3 primary considerations for selecting a site; 1) Amount of water available2) Type of water available3) Location accessibilitySource should have 24 inches of water above and below the strainerMaximum lift is 20 feet
57 Drafting Use side intakes Close pump to tank valve Remove keystone or piston intakeConnect hard suctionCan prime either in or out of pump gearWhen in pump gear, increase rpm’s to 1200 and pull primer for not more than 45 sec.
58 Drafting Priming typically requires 15-20 seconds Most common problem is air leakAfter pump has been primed, increase pump pressure to psi prior to opening any dischargeOpen discharge valve SLOWLYIf pressure drops, momentarily engage primer
59 Drafting Do not engage pressure governor until flowing water If pressure governor is on prior to obtaining prime and apparatus is in pump gear, will sense increase in rpm without corresponding increase in pressure and return engine to idle.Flush pump with clean water ASAP
60 HH HOUSTON FIRE DEPARTMENT PUMP OPERATOR PROGRAM VAL JAHNKE FIRE TRAINING FACILITYHH