Fire Pumps Flashcards
Fire pumps are rated for a net pressure of ____ or more
40 psi
Fire pumps rated for 5000 gpm and over are subject to individual review by
Authority having jurisdiction
When installing fire pumps, steel pipe must be used ______
Above ground
What is tuberculation
Small Knobs or buttons of rust on the inside of the pipe
What is used to prevent tuberculation
Galvanized or painted on the inside of piping
What is not permitted with pipe & fittings
Thick bituminous linings
Steel piping is joined by
Screwed
Flanged
Welded
Grooved
When can slip type fittings be used
-When piping is mechanically secured to prevent slippage
-When pump and its suction supply are on separate foundations
NFPA 51B is the standard for
Fire prevention in use of cutting and welding process
All pump discharge pipes are required to be _____
Hydrostatically tested
What must be installed in the pump discharge assembly
Back-flow preventor or check valve
What can large systems experience when a fire pump shuts down
Water hammer
What shall be installed on the system side of the check valve
Butterfly or gate valve
A clearance of not less then ____ inch is required around all pipes that pass through walls or floors
1”
Holes through the pump room fire walls should be packed with
Mineral wool
Holes through fire pump floor may be filled with
Asphalt mastic
Gauge located on or near discharge casting size
3-1/2” diameter
Gauge located on or near discharge pressure scale and units
-At least twice the rated working pressure of the pump, not less then 200psi
-Must read in Bar, or PSI
Suction pipe gauge is a
Vacuum and compound pressure gauge
Suction pipe gauge size
3-1/2”
Suction pipe gauge must read in what units and have a scale of
-Inches of mercury (Hg) or PSI
-2x rated maximum suction pressure, not less then 100psi
Fire pump is any device which does what
Takes water from any type of source and increases the pressure of that water
Jockey pumps are also referred to as
Pressure maintenance pumps
Why are jockey pumps installed
To increase system pressure without turning fire pump on
Jockey pump is designed so it
Comes on before fire pump and returns system to its minimum static pressure
Jockey pumps are usually ____ pressure and ______ flow pumps
High pressure, Low flow pumps
2 types of pumps found in fire protection are
Centrifugal and positive displacement
Most common kind of pump in fire protection is
Centrifugal pump
What is the most important part of a centrifugal pump
Impeller
What guides water from the eye to the discharge to avoid turbulence
Vanes
Vanes on impeller are curved
Away from the direction of rotation
Single suction impeller is
Water enters the eye on one side
Double suction impeller is
Water enters the eye on both sides
What allows the shaft to pass through the pump while maintaining an air tight seal
Packing
Each entrance and exit of shaft must have
Packing
Packing material is designed to be lubricated with
Water
What happens if the packing gland is over tightened
Packing will dry out, crumble, cause pump damage
How often should pump run to lubricate packing
Once a week
Pumps with only one impeller are how many stages
1 stage
Volume and pressure rating in single stage pump are determined by
Size of impeller
Speed at which it rotates
Pumps with more then one impeller on same shaft are
Multiple stage pumps
Number of impellers on shaft determines what
Number of stages
Multiple stage pumps can operate in 2 different manners which are
In series, and in parallel
Pumping in parallel increases
Total flow from pump
Pumping in series increases
Total pressure output of the pump
Multistage pumps are often used in
Series
Horizontal pump is
Shaft between the engine and the impeller is run in horizontal plane
Vertical pump is
A pump where the shaft between engine and the impeller is run in a vertical plane
What is a end suction pump
Single suction pump
On opposite side of stuffing box
Horizontal split case pump is
Horizontal pump where the casing is split along the same axis as the shaft between engine and impellers
in-line pump is
Any pump with suction and discharge flanges along centreline
Vertical (shaft) turbine pump is
Pump with impellers suspended by conductor system. Vertical shaft is along the same axis as the discharge from impeller
What is the only pump exempt from needing Postive pressure at the suction
Vertical (Line) shaft turbine pump where
What pump is designed to bring water from a static source
Vertical (Line) shaft turbine pump
Can pump is slang for
Vertical in line type pump or any vertical pump installed in a pipe for boosting pressure rather then from a static source
Why is an eccentric tapered reducer used on suction side of fire pump
Avoids turbulence and air pockets
How should eccentric reducer be installed
Flat side on TOP
If suction can go below 20 psi, what is needed
Compound gauge capable of registering negative pressure on suction
When taking suction from a tank the suction pressure cannot drop below
0 psi while pump is @ 150%
What can happen if a negative suction pressure happens
-Fire pump and piping could
Cavitate
-infiltration of ground water
Discharge pressure gauge is beneficial to be
Liquid filled (they dampen the pressure fluctuations)
What does an automatic air release do
Reales air in casing that could cause impeller damage
Relief valves are not intended too
Control pressure, they are intended to relief pressure from overspeed
What is a way to look at discharge with relief valve
Sight glass
What is the purpose of the discharge check valve
keep pressurized liquid from coming back through fire pump
What is necessary for a jockey to keep pressure on system
Check valve
Valve on test header is supervised in the normally ____ position
Closed
Most common way of testing a fire pump
Test header
What’s the purpose of a flow metre
Measure flow rate from fire pump if in a loop piped back to the pump suction
If a flow metre is used, what must be done every 3 years
Discharge performance test
Fire pump controllers purpose is too
Monitor, start/stop fire pump.
What kind of switch is used to tell the controller to start the fire pump
Mercoid or pressure transducer
Jockey pump must have its own
Controller
Where is fire pump sensing line connected
One end to Myceroid/pressyrw transducer within controller and other end to FP piping between discharge check and control valve
When May jockey pumps require 2 check valves
With high pressure fire pump.
(Check holds pressure on the system so when fire pump is on the pressure does not go through Jockey)
FDC should be installed where with fire pumps
Downstream of the fire pump discharge check valve
How is back pressure avoided with exhausts
Proper sizing and fittings
Purpose of fire pump bypass
Allows the water supply to provide some pressure to the system should the fire pump fail
Diesel engine battery have how much capacity
2x the capacity at 40F, sufficient to maintain cranking speed
Battery’s must be capable of
- 3 minute attempt to start cycle
-15 seconds of cranking & 15 seconds of rest
- 6 times
Where is heat exchanger fed from
Pump discharge
Controllers should be located
Within sight of the motors
Controllers will show net pressure up too
400psi
Pump house maintained at
40F
Electric monthly pump run time
10 minutes
Fuel tanks shall be kept a minimum of
2/3rds full
Most common cooling method is
Constant flow heat exchanger
Diesel fire pump for how long
30 minutes
Engine must reach operating speed within
20 seconds
Annual fire pump test (electric driven pumps) when is voltage and amperage recorded
Each of the 3 phases
How is pump speed measured
A tachometer or speed counter
Annual pump test is how long
30 minutes
Power failure condition should be simulated at
Peak load (150%)
The controller should provide a crank cycle for how long
3-15 seconds
Lubricating oils should be replaced after how many hours
50
NFPA for generators
NFPA 110
Sensing line pipe size
Not less then 1/2”
-brass, copper, series 300 stainless steel
If a water pulsation causes erratic operation, what is required
Supplemental air chamber, or pulsation damper
How many check valves in sensing line and what is in them
- 2 check valves
- 3/32 hole in clapper
When can check valves with 3/32 hole for sensing line be omitted
With clean water, ground face unions with non corrosive diaphragms drilled at 3/32 instead
Where is a pump coupling used
To connect the rotating pump shaft to the drive shaft of the motor
When is a pump coupling not required
If a pump is close coupled (on single shaft)
A close coupled to pump has the impeller directly mounted to the
Motor shaft
Rigid coupling is
Coupling that permits little to no movement between the shafts
(Best for precise alignment)
Flexible coupling is
Any coupling that can permit some degree of relative motion between the shafts
Sleeve or muff coupling is
-Simplest of the rigid couplings
-cast iron sleeve
-gib head key is used to restrict relative motion
Flange coupling is
Coupling with flange put onto each shaft
What is a Gear coupling
-Similar to flange coupling but is flexible
-can accommodate misalignment of 0.25-0-5mm (2 degrees)
What is a universal joint (hooked joint)
For when 2 shafts are parallel, and intersect at a small angle
Oldham coupling is
-used exclusively for lateral shaft misalignment
Diaphragm coupling is
Great all rounder shaft coupling. Can accommodate misalignment as well as high angular and axial misalignment
Jaw coupling is
-Material fabric coupling
-low power transmission and motion control applications.
Beam coupling is
-Machined coupling
-high flexibility
-the best for low power transmission
Churn pressure is
No flow, pump is running but no water moving
What is rated pressure
100% of pump demand
What is peak demand
150% of pump demand
Net pressure is
Pressure produced by a pump
Rating of fire pump is determined by
The hydraulic calculation and available water supply
Lantern ring is only installed where supply is less then
30 psi
Dual impeller design
670’ of head rated for 290psi
Vertical In line impeller orientation
Rotates horizontal
Net pressure for vertical in line pumps
175psi
End suction pumps max gpm and net pressure
1500gpm
159psi
Cannot get an End suction pump less then how many gal in fire protection
500gal
Horizontal split case impeller orientation
Rotates on vertical plane
Horizontal split case gpm and psi
250-5000gal
Net 640psi
Size of circulation relief valve for pumps not more then 2500gpm
3/4”
Size of circulation relief valve for pumps 3000-5000gpm
1”
Pumps connected to adjustable speed drivers shall have
Listed relief valve
2 types of relief valves are
Spring loaded
Pilot operated diaphragm
The relief valve shall NOT be piped too
The pump suction of supply connection
Hose valves shall have the
NH standard external thread as per NFPA 1963
Metering devices/fixed nozzles for fire pump testing shall be listed for water flow of not less then
175% of pumps rated capacity
Where is the water inlet for an end suction pump
The water inlet is at the end, rather then on the side
Where is the motor mounted for a horizontal shaft split case pump
Beside the pump
Horizontal pump 3 designs are
Split case
End suction
In Line
The motor and pump are usually mounted on ______ for Horizontal shaft split case pump
A common base plate and connected W/ a coupling
Where is the electric motor mounted for the horizontal split case vertically mounted in pump
On top/above pump
Inline pump is defined as
Variation of end suction style, with the inlet and outlet connections in a straight line
As capacity increases, the total
Pressure that the pump is capable of developing is
Reduced
When is the highest point of pressure with a fire pump
Churn
The gauge at a pump suction tank shall be capable of
Dropping to -3psi with the lowest water level after
Size of bypass around fire pump
At least as large as the pipe size required for the discharge pipe
Elbows with the centreline plane parallel to the pump should be
Avoided, unless the distance between suction flange and elbow is 10x suction pipe diameter
Horizontal shaft pumps are usually what volute type
Double suction
Suction supply control valve must be what kind of valve
OS&Y
If a butterfly valve is used on fire pump discharge, they must not be installed within
50 feet of the pump suction flange
What is cavitation
Formation of air bubbles, or cavities that collapse into yep they reach high pressure
What does cavitation do to fire pumps
-Produce high pressure surges
-blast particles out of impeller
-cause a drop in efficiency
-vibration can cause bearing failure, shaft breakage
Where suction supply is from public water mains, the gate valve should be located
As far as practical from suction flange on pump
Where the suction comes from a stored water container, the gate valve should be located
At the outlet of container
Exceptions of devices in suction piping
-Shut off valve
-Check valves/backflows
-Pressure sensitive flow control valves
Pumps that are automatically controlled must be provided with a
Listed float operated air release not less then 1/2” in size
When is an automatic air release not required
For end suction pumps with top centre line discharge valve or in line pumps
Pumps rotate which direction
Both clockwise and counter clockwise
Diesel engines are commonly stocked and supplied to rotate
Clockwise
The pump and driver shall be mounted on a
Common base plate
The foundation top for fire pump pad should be how far below desired finish and why
3/4”-1 1/2” for grout
Prior to grouting what is done to pad
Roughen the foundation top with chisel
After pad is grouted, alignment is checked after how long
48 hours
Purpose of flexible coupling is
Compensate for temperature change, permit end movement of shafts
What is angular misalignment
Shafts with axis that are concentric but not parallel
Parallel misalignment is
Shafts with axis that are parallel but not concentric
Angular alignment is checked with
Taper gauge or feeler gauge
How do you check parallel alignment
Placing straightedge across both coupling and rims at the top bottom and both sides
Are are misalignments corrected
Shims under motor mounting feet
The best method final accurate alignment for coupling halves is done with
Dial indicator
What does the arrow on pump indicate
The direction of the rotation of the pump
After unit has been in operation for 10 hours or three months what is done
Final check for misalignment
Horizontal shaft pumps after lubricated with
Water
If pump is forced to operate and the packing gland is too tight, how much x the normal current is need
6x
Minimum churn pressure is
101% of rated pressured
Max churn pressure is
140% of rated pressure
How far apart are the check valves in sensing line
Minimum 5 feet apart
The turbine pump is what kind of pump
Vertical shaft centrifugal pump
The column pipe in a turbine pump as serves as
Support for the shaft and bearings
Turbine pump is suitable for when water source is
Below ground
What kind of turbine pump protects the pump from sandy/dirty water
Oil lubricated pumps
When a vertical shaft turbine pump is in a well, the pump bowl assembly shall not be less then
Second impeller is 10 ft below the pumping water level @ 150% of rated capacity
(Submergence must increase 1 foot every 1000ft of elevation)
When a vertical shaft turbine pump is used in a wet pit, where is the pump bowl
Second impeller from the bottom is Below the lowest pumping water level in the open body of water
The distance between the bottom strainer and the Bottom of the wet pit shall be at least
One half the pump bowl diameter but not less then 12”
Minimum size of air release on vertical shaft turbine pump
1-1/2”
All vertical pump installations are required to have a
Non-reverse ratchet
Current carrying parts on controllers shall not be less then how far from ground
12”
A fire pump controller cannot be used as what
Junction box for any other equipment
Most controllers for sprinkler systems are
Automatic
A pressure switch must have the capability of having how much pressure put on it
400 psi or 133% of the controllers rated operating pressure
Pressure switch cannot contain a
Pressure snubber or restricted orifice
Pump must start within how long after alternate power is put on
15 seconds
If more then one pumping unit is used, the units shall start at intervals of
5 to 10 seconds
If a controller is set for an automatic shut down, after everything returns to normal, what is the minimum timer
10 minutes
Spark ignited Internal combustion engines are not permitted for installations since when
1974
What type of battery for diesel
Lead acid
Battery location for diesel
Must be rack supported
Min 12” from floor
Where is the supply cooling water for the engines heat exchanger taken from
Discharge side of pump on pump side of the discharge check
Each clean filter in bypass for cooling water line shall permit full water flow for how long
3 hour
Waste outlet from heat exchanger size
Not be less then one size larger then inlet line.
If more then 15 feet of pipe is used/outlet is more than 4 feet higher than the heat exchanger, pipe must be increased by 1 size
Fuel supply line must be located where
5% above bottom of tank
A seamless, flexible connection of not less then ____ between the engine exhaust outlet and the pipe
12”
If exhaust is longer then 15 feet what must be done
Increase one pipe size larger then engine exhaust outlet
(Plus for every 5 feet past the 15 feet, additional 1 pipe size is added)
Engine jacket heater temp
120F
At what temp do diesel engines require water and oil heaters
70F
What is the “attempt to start” cycle
Six crank periods
15 second duration or cranking
15 second rest period
What is the jockey pump start & stop point
Stop - Churn pressure + minimum static pressure
Start - 10psi below stop
Fire pump start point
5 psi less then jockey
Min pressure @ peak performance is
Cannot be less then 65% of pump demand (rated pressure)
Main role of lantern ring
Stop air from being sucked into suction casing
Pump packing drip minimum
1 drip per second
Packing materials
Rope with Polytetrafluorethylene
Rope with Graphite
What kind of flow is best?
Laminar
Each valve on test header (2 1/2) is capable of how much gpm
250
Controllers are rated for what HP
30hp
Controller voltage
600v or less
Most common controller for electrical pump
Full service
How many phases on automatic controller
3 phase
What kind of motors on electric fire pump
Squirrel cage or wound Rotor motors
Diesel pump room maintained at what temp
70F
Electric fire pump room min temp
40F
Clearance requirements for controller
3 feet
Types of impellers
Open
Semi closed
Closed
Types of driver mounting methods for centrifugal pumps
Frame mounted
Close coupled
Separately coupled
What supports the electric motor on a vertical pump
C-Frame
2 different types of positive displacement pumps are
Reciprocating & Rotary
What type of pump is a diaphragm pump
Reciprocating
What type of pump traps fluid and rotates it to the discharge outlet
Rotary
What type of pump is an excess pressure pump
Rotary external gear pump
What type of bearing configuration does an end suction pump have
Overhung impeller
Where should a pressure relief valve be installed on a fire pump
Between discharge flange and check valve
What must be provided in all valve rooms
Heat
Lighting
Drain
Ventilation
Where are positive displacement pumps used
Wet systems
Foam systems
Water mist systems
Types of fire pumps that an electric driver motor can be attached too
Vertical inline/Turbine
Horizontal split case
Vertical split case
End suction
What additional equipment do you need when installing electric driven fire pumps
-Variable speed controller
-Generator
What do you need if a power source is not deemed adequate for a fire pump
Power transfer switch
Alternate power
Types of fire pumps that can be connected to a diesel engine driver
-Horizontal split case
-End suction
-Vertical Turbine with right angle gear drive
Three methods for starting diesel driven fire pumps
Battery
Hydraulic
Pneumatic
Testing pressure for all piping serving fire pumps
200 psi or 50 psi in excess of normal pressure
What device is used to keep fire pump cool during a churn test
Circulation relief valve
Minimum distance backflow shall be from suction of fire pump
10x pipe diameter
How often are test gauge calibrated for fire pump flow test
Annually
Where is the test connection located on the discharge side of a fire pump
Between discharge check and discharge control valve
Another term used for churn pressure
Shut off
What component helps reduce velocity and increase pressure
Volute casing
What is the required minimum velocity when flushing piping serving a fire pump
15ft/sec
4 most common couplings we used are
Disc coupling
Jaw coupling
Grid coupling
Universal Joint coupling
