HH H OUSTON H OUSTON F IRE F IRE D EPARTMENT P UMP P UMP O PERATOR O PERATOR P ROGRAM VAL JAHNKE...
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Transcript of HH H OUSTON H OUSTON F IRE F IRE D EPARTMENT P UMP P UMP O PERATOR O PERATOR P ROGRAM VAL JAHNKE...
HHHHOOUUSTSTONON FFIIRERE DDEEPAPARTRTMEMENNTT
PPUUMPMP OOPPERERATATOROR PPRROOGRGRAMAM
VAL JAHNKE FIRE TRAINING FACILITY
Pump Equipment
• Centrifugal Pump• Pressure Relief Valve/Governor• Intake Relief Valve• Transfer Valve• Positive Displacement Primers• Manual Pump Shift• Gauges• Auxiliary Cooler
Centrifugal Pump
• Non-positive displacement pump
• Three factors influence pump discharge pressure
1) Incoming pressure, 2) Speed of the impeller, and 3) The amount of water being discharged
• Single or multi-stage• NOT self-priming• Cavitation
Pressure Relief Valve/Governor
• Most common devices
• Set while discharging at operating pressure
• Set for highest operating pressure
• Pressure relief valve - diverts water
• Pressure governor - controls rpm
Intake Relief Valve
• Also known as dump valve
• Protects pump from water hammer and excessive intake pressure
• Possibly capped during high pressure operations
• Piston intake relief valve
Transfer Valve
• Multi-stage pump only
• Pressure (series) vs. Volume (parallel)
• Most operations in pressure mode
• 50% rule
• Change over @ 50 psi net pump pressure
Positive Displacement Primers
• Required for drafting
• Most common - rotary vane
• Operate for no more than 45 seconds
• Priming oil
• Environmentally safe primers
Manual Pump Shift
• Provides back-up
• Usually located on pump panel
• Often require two persons to operate
• Back-up throttle may have to be used
• Exercise manual shift often
Gauges
• Compound gauge
• Master intake gauge (compound)
• Master discharge gauge
• Individual discharge gauge
• Engine gauges
Auxiliary Cooler
• Allows water from pump to cool engine
• Use when temperature exceeds normal level
• Close when temperature returns to normal
• Keep in closed position
Valves
• Main intake valve (suction)-keystone, piston, MIV• Auxiliary intake valve ( 2 ½ ) • Tank-to-pump valve• Tank fill valve• Discharge valves• Pump drain valve• Discharge drain valve• Intake drain valve
Water Supply
Booster Tank
• Sizes
• Tank-to-pump valve
• Use only one handline
• Obtaining positive source
• Refill as soon as possible
Hydrant Operations
• Two types of hydrants
• Steamer should face street
• Blue reflectors assist in locating
• Color coded to main size
• MUD Districts may not color code
• Private hydrants - Apartments, Businesses
Water System Consumption
• Peak use hours
– Morning - residential areas
– Mid day - downtown areas
– Evening - residential areas• May contact Water Department to divert
water to fire area
Drafting
• Primary source for rural fire protection
• Portable water supplies
• Static water supplies
Hydraulics
Theory of Pressure
• Force: measure of weight
• Pressure: measure of force per unit area
Pressure and Fluids
• Pressure acts on fluids according to six basic principles– Fluid 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.
Hydraulic Calculations
Engine Pressure = nozzle pressure + friction loss in the hose + friction loss in appliances + pressure due to elevation
Nozzle Pressure - The amount of pressure required at the nozzle to produce an effective fire stream.
Nozzle Pressures
• Fog nozzle 100 psi
• Low pressure fog nozzle 75 psi
• Vindicator nozzle (minimum) 50 psi
• Solid stream handline 50 psi
• Solid stream master 80 psi
Friction Loss
The 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
FL = C · Q · L
• FL = friction loss in psi
• C = coefficient ( constant )
• Q = flow rate in GPM/100
• L = hose length in feet/100
Friction Loss Coefficients
• 1¾” - 15.5
• 2½” - 2.0
• 3” - .80
• 4” - .20
Example
If 200 gpm is flowing from a nozzle, what is the friction loss in 200 ft. of 2½” hose?
FL = C · Q · L
C = 2
Q = gpm/100 = 200/100 = 2
L = length/100 = 200/100 = 2
FL = (2) (2) (2) = (2) (4) (2) = 16 psi
GPM Formula
• It 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 ·NP
GPM = 29.7 ·d2 ·NP
GPM= Discharge in gallons per minute
29.7 = A constant
d = Diameter of the tip (inches)
NP = Nozzle pressure in psi (square root)
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)
= 1069.2 GPM (1070)
Solid Stream Handline @ 50 psi
Tip Size GPM
1” 210
1 1/8” 265
1 1/4” 325
Solid Master Stream @ 80 psi
Tip Size GPM1 ½” 6001 ¾” 8002” 1000
2 ¼” 13452 3/8” 15002 ½” 1660
Appliances
• Reducers
• Gates
• Wyes
• Manifolds
• Heavy Stream Piping
Appliance Friction Loss
• Small appliances:– Less than 350 GPM - no friction loss– More than 350 GPM - 10 psi friction loss
• Master streams:– 25 psi friction loss
Standpipes
• No friction loss for piping
• Allow for elevation only
• 5 psi per floor for elevation
• Can be negative number– pumping to basement
Total Engine Pressure
• EP = NP + FL + Appliance + Elevation
Example
• What 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 + Elevation
EP = 75 + 125 + 0 + 15
EP = 215 psi
Wyed Hoselines
• Complex pumping situation
• Common with apartment lay
• Same size and type
• Different size
• Communication with crews
Pressure vs. Volume
• Common misconception
• Maximum capacity at draft
• Maximum capacity with positive pressure
• Net pump pressure
Calculating Additional Water Available
• Static pressure
• Residual pressure
• Percentage drop: static -residual
• Formula– Percentage Drop = (Static - Residual) (100)
» Static
Water Available Table
Percent Decrease Water Available
0 - 10% 3 x amount
11 - 15% 2 x amount
16 - 25% same amount
Over 25% less than being delivered
Specialized Pump Operations
Multiple Discharges
• Different Pressures
• Different Friction Loss Calculations
• Gating Back Discharges
• Set Pressure Relief Device/Governor
Master Streams
• Most Common - Deck Gun, Ladder Pipe
• Nozzle Tips Flowing 400-1500 GPM
• Solid Bore - 80 psi Nozzle Pressure
• Fog Nozzle - 100 psi Nozzle Pressure
• 25 psi Friction Loss
Standpipes and Sprinklers
• Usually have a 2 ½” connection
• Hook up with 3” high pressure hose or 4” hose with adapter
• Reverse lay
• DO NOT PUMP UNLESS ORDERED
Non-PRV Systems
• Standpipe:– Fog Nozzle: 150 psi + 5 psi per floor– Solid Stream 65 psi + 5 psi per floor
• Sprinkler:– 150 psi + 5 psi per floor
• Elevation loss is calculated to the fire floor
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
zone
• When pumping into a PRV system, the standpipe outlet pressure cannot be raised above its designed pressure
Relay Pumping
• Necessary when the required GPM flow of the attack pumper cannot be met because of friction loss in the supply line
• Pump pressure is based on GPM needed and distance between pumpers
• 20-50 psi residual in addition to friction loss
• Relay initiated by pumper at water source
Relay Pumping
• Intermediate pumpers - close pump to tank valve, open 2½” discharge until water discharges, close discharge, place in pump gear and open supply to next pumper
• Discharge pressures should not exceed 200 psi, if pressure required to supply water is greater than 200 psi, another pumper or additional lines are needed
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.
Foam OperationsPortable Eductors
• Do not start foam operations unless incident can be terminated with resources available
• Portable eductors require 200 psi @ eductor• Emulsifiers can be educted @ 1/2 or 1%• Nozzle setting must be @ 95 gpm• Apparatus will carry 6 - 5 gallon containers
of foam and 2 - 5 gallon containers of cold clean
Foam Operations
• Portable 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 flushing
• Maximum length from eductor to nozzle is 300 ft of 1 3/4” hose or a combination of 1 3/4” and 2 1/2” hose not exceeding 450 ft
Permanently Mounted Eductor
• Similar to portable eductor
• Require same pressure @ eductor
• Maximum hose length from eductor to nozzle - 300 ft of 1 3/4” hose or a combination of 1 3/4” and 2 1/2” hose not exceeding 450 ft
• Proportioning valve located on pump panel
Direct Injection Foam System
• Uses a pump to inject the emulsifier/foam into a discharge pipe that connects the fire pump and designated foam discharges
• Controlled by electronic keypad
• Two tanks - 40 gallons foam, 10 gallons emulsifier
• System is self adjusting, regulated by flow meter
Direct Injection Foam System
• Intake pressure kept below 50 psi• Minimum pump pressure is intake pressure
plus 100 psi• Maximum pump pressure 250 psi• Set engine pressure according to hoselay and
nozzle• Foam and emulsifier flows only through
designated discharges
Direct Injection Foam System
• Can flow water through non-foam discharges simultaneously
• To flush system, decrease pump pressure to 100 psi and place toggle switch in flush position - flush system for 20 seconds
• Turn foam system off and flush hoseline for 5 minutes
Drafting
• 3 primary considerations for selecting a site;
1) Amount of water available
2) Type of water available
3) Location accessibility
• Source should have 24 inches of water above and below the strainer
• Maximum lift is 20 feet
Drafting
• Use side intakes
• Close pump to tank valve
• Remove keystone or piston intake
• Connect hard suction
• Can prime either in or out of pump gear
• When in pump gear, increase rpm’s to 1200 and pull primer for not more than 45 sec.
Drafting
• Priming typically requires 15-20 seconds• Most common problem is air leak• After pump has been primed, increase pump
pressure to 50-100 psi prior to opening any discharge
• Open discharge valve SLOWLY• If pressure drops, momentarily engage primer
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
HHHHOOUUSTSTONON FFIIRERE DDEEPAPARTRTMEMENNTT
PPUUMPMP OOPPERERATATOROR PPRROOGRGRAMAM
VAL JAHNKE FIRE TRAINING FACILITY