Transcript Engineer/Operator Program - Louisiana State University

HOUSTON FIRE DEPARTMENT
HH
PUMP OPERATOR PROGRAM
VAL JAHNKE FIRE TRAINING FACILITY
Pump Equipment
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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
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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
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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
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Required for drafting
Most common - rotary vane
Operate for no more than 45 seconds
Priming oil
Environmentally safe primers
Manual Pump Shift
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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
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Compound gauge
Master intake gauge (compound)
Master discharge gauge
Individual discharge gauge
Engine gauges
Auxiliary Cooler
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Allows water from pump to cool engine
Use when temperature exceeds normal level
Close when temperature returns to normal
Keep in closed position
Valves
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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
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Sizes
Tank-to-pump valve
Use only one handline
Obtaining positive source
Refill as soon as possible
Hydrant Operations
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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
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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
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FL
C
Q
L
= friction loss in psi
= coefficient ( constant )
= flow rate in GPM/100
= hose length in feet/100
Friction Loss Coefficients
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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
1 ½”
1 ¾”
2”
2 ¼”
2 3/8”
2 ½”
GPM
600
800
1000
1345
1500
1660
Appliances
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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
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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
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Complex pumping situation
Common with apartment lay
Same size and type
Different size
Communication with crews
Pressure vs. Volume
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Common misconception
Maximum capacity at draft
Maximum capacity with positive pressure
Net pump pressure
Calculating Additional Water Available
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Static pressure
Residual pressure
Percentage drop: static -residual
Formula
– Percentage Drop = (Static - Residual) (100)
»
Static
Water Available Table
Percent Decrease
0 - 10%
11 - 15%
16 - 25%
Over 25%
Water Available
3 x amount
2 x amount
same amount
less than being delivered
Specialized Pump
Operations
Multiple Discharges
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Different Pressures
Different Friction Loss Calculations
Gating Back Discharges
Set Pressure Relief Device/Governor
Master Streams
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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 Operations
Portable 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
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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
HOUSTON FIRE DEPARTMENT
HH
PUMP OPERATOR PROGRAM
VAL JAHNKE FIRE TRAINING FACILITY