WEEK 4 FIRE PUMPS Questions with
Correct Answers
During operation, the suction gauge reads 57 and the discharge gauge reads 139. The
net is: Correct Answer 82 psi
"Churn" pressure is another term used for: Correct Answer Shutoff pressure
When suction pressure can be below 20 psi during pump operation, the suction gauge
must read: Correct Answer Negative pressure in inches of mercury
A wide impeller would result in: Correct Answer Higher volumes with higher pressures
A 3000 gpm vertical turbine fire pump must have an air release valve of what size?
Correct Answer 1-1/2"
State the minimum size of discharging piping for a circulation relief valve on a 2000 gpm
pump. Correct Answer 3/4"
Identify the component of the pump that helps to reduce velocity and increase pressure.
Correct Answer Volute casing
Why are check valves preferred over ground face unions for sensing line installations?
Correct Answer They act as a fail safe for pump operation
Diesel fuel tanks must be maintained at: Correct Answer 1/3 empty or 2/3 full
In a closed loop metering arrangement, what additional component is required? Correct
Answer Air release
In a fire pump arrangement, the pressure relief valve is installed where? Correct Answer
Between the pump and discharge check valve
What is the required minimum velocity for flushing the suction piping to a fire pump?
Correct Answer 15 ft/sec
What does a pressure maintenance pump do? Correct Answer It is capable of
maintaining pressure
Determine the fire pump start pressure if churn pressure is 85 and supply pressure is
50. Correct Answer 120 psi
When aligning a fire pump and driver, if the gap between couplings is not equal it is due
to: Correct Answer Angular misalignment
, What may be required to assist in the lubrication of packing? Correct Answer Lantern
rings
What is installed to protect the pump shaft from damage? Correct Answer Sleeves
What will a pump room with a diesel driver require that one with an electric driver will
not? Correct Answer Louvers (Ventilation)
How far from the suction flange of the fire pump must a backflow preventer be installed?
Correct Answer 10 pipe diameters
When an eccentric reducer is required, how is it installed? Correct Answer Suction side-
flat on top, taper on bottom.
How do you figure out net pressure? Correct Answer Discharge - suction = net pressure
How do you figure out fire pump start pressure? Correct Answer Churn pressure +
supply pressure - 15 = fire pump start pressure
Define churn/shutoff pressure. Correct Answer The pressure developed by the pump
with no flow- 0%
Define rated pressure. Correct Answer The pressure developed by the pump when
flowing 100% of pump demand.
Define peak pressure. Correct Answer The pressure developed by the pump when
flowing 150% of pump demand.
Define net pressure. Correct Answer Pressure actually produced by a pump.
What is the purpose of a fire pump? Correct Answer To boost pressure and meet flow
demand from an available water source.
What is the minimum, typical and maximum churn/shutoff pressures? Correct Answer
101%- minimum of rated pressure
120%- typical of rated pressure
140%- maximum of rated pressure
When is a pressure relief valve required on a diesel pump? Correct Answer When 121%
of the rated churn pressure + static supply pressure exceeds 175%
What are the two types of pumps? Correct Answer Centrifugal and Positive
Displacement
What is single suction? Correct Answer When water enters on only one side of impeller
Correct Answers
During operation, the suction gauge reads 57 and the discharge gauge reads 139. The
net is: Correct Answer 82 psi
"Churn" pressure is another term used for: Correct Answer Shutoff pressure
When suction pressure can be below 20 psi during pump operation, the suction gauge
must read: Correct Answer Negative pressure in inches of mercury
A wide impeller would result in: Correct Answer Higher volumes with higher pressures
A 3000 gpm vertical turbine fire pump must have an air release valve of what size?
Correct Answer 1-1/2"
State the minimum size of discharging piping for a circulation relief valve on a 2000 gpm
pump. Correct Answer 3/4"
Identify the component of the pump that helps to reduce velocity and increase pressure.
Correct Answer Volute casing
Why are check valves preferred over ground face unions for sensing line installations?
Correct Answer They act as a fail safe for pump operation
Diesel fuel tanks must be maintained at: Correct Answer 1/3 empty or 2/3 full
In a closed loop metering arrangement, what additional component is required? Correct
Answer Air release
In a fire pump arrangement, the pressure relief valve is installed where? Correct Answer
Between the pump and discharge check valve
What is the required minimum velocity for flushing the suction piping to a fire pump?
Correct Answer 15 ft/sec
What does a pressure maintenance pump do? Correct Answer It is capable of
maintaining pressure
Determine the fire pump start pressure if churn pressure is 85 and supply pressure is
50. Correct Answer 120 psi
When aligning a fire pump and driver, if the gap between couplings is not equal it is due
to: Correct Answer Angular misalignment
, What may be required to assist in the lubrication of packing? Correct Answer Lantern
rings
What is installed to protect the pump shaft from damage? Correct Answer Sleeves
What will a pump room with a diesel driver require that one with an electric driver will
not? Correct Answer Louvers (Ventilation)
How far from the suction flange of the fire pump must a backflow preventer be installed?
Correct Answer 10 pipe diameters
When an eccentric reducer is required, how is it installed? Correct Answer Suction side-
flat on top, taper on bottom.
How do you figure out net pressure? Correct Answer Discharge - suction = net pressure
How do you figure out fire pump start pressure? Correct Answer Churn pressure +
supply pressure - 15 = fire pump start pressure
Define churn/shutoff pressure. Correct Answer The pressure developed by the pump
with no flow- 0%
Define rated pressure. Correct Answer The pressure developed by the pump when
flowing 100% of pump demand.
Define peak pressure. Correct Answer The pressure developed by the pump when
flowing 150% of pump demand.
Define net pressure. Correct Answer Pressure actually produced by a pump.
What is the purpose of a fire pump? Correct Answer To boost pressure and meet flow
demand from an available water source.
What is the minimum, typical and maximum churn/shutoff pressures? Correct Answer
101%- minimum of rated pressure
120%- typical of rated pressure
140%- maximum of rated pressure
When is a pressure relief valve required on a diesel pump? Correct Answer When 121%
of the rated churn pressure + static supply pressure exceeds 175%
What are the two types of pumps? Correct Answer Centrifugal and Positive
Displacement
What is single suction? Correct Answer When water enters on only one side of impeller
