NFPA 24 (TFM10) FIRE HYDRANT TESTING EXAM 2025 | 86
QUESTIONS WITH ACCURATE SOLUTIONS
1. In a scenario where a city is conducting a flow test to evaluate its water
supply system, what would be the significance of using a flow hydrant?
It allows for accurate measurement of water flow, ensuring the
system meets required standards.
It provides a connection point for firefighters during emergencies.
It helps in identifying leaks in the piping system.
It serves as a backup water source for residential areas.
2. Why is it important for mains supplying fire hydrants to have a minimum
pipe size of 6 inches?
A minimum pipe size of 6 inches ensures adequate water flow
and pressure for firefighting purposes.
A minimum pipe size of 6 inches is required for aesthetic reasons.
A minimum pipe size of 6 inches prevents corrosion in the pipes.
A minimum pipe size of 6 inches is necessary for easy installation.
3. If a water supply system is tested at an average pressure of 150 psi during
a hydrostatic test, what implications does this have for the system's
integrity?
The system must be able to withstand pressures above 150 psi
without leaking or failing.
The system is guaranteed to function properly at 150 psi.
The system can only operate safely at 100 psi.
The system's integrity is not affected by the test pressure.
4. What is the primary function of an indicating valve?
, To provide the valve operating condition, open or closed.
To regulate water flow in piping systems.
To prevent backflow in water supply systems.
To measure water pressure in hydrants.
5. What does the variable 'L' represent in the Hydrostatic Testing Allowance
Formula?
Length of the pipe
Diameter of the pipe
Pressure in psi
Safety factor
6. What is the minimum pipe diameter that feeds a hydrants?
6 inches
4 inches
8 inches
5 inches
7. What is the primary purpose of a private fire hydrant?
To supply hose and fire department pumpers with water on
private property.
To provide drinking water to residents.
To drain excess water from the property.
To serve as a decorative feature in landscaping.
8. Describe the process involved in conducting a hydrostatic test on a
piping system.
, The process involves increasing the internal pressure of the
piping system for a specified duration to check for leaks and
ensure integrity.
The process involves draining the system and inspecting for
corrosion.
The process involves flushing the system with water to remove
debris.
The process involves measuring the flow rate of water through the
system.
9. What is the specified height range for post indicator valves above final
grade according to the document?
32 in - 40 in (800 mm to 1000 mm)
24 in - 30 in (600 mm to 750 mm)
40 in - 48 in (1000 mm to 1200 mm)
28 in - 36 in (700 mm to 900 mm)
10. What is the value of "D" in the equation used to size gas piping by
computing the maximum demand quantity?
Demand (maximum cfm)
Inside diameter of the pipe (inches)
Demand (maximum cfh)
Outside diameter for pipe (inches)
11. Fire hydrant used during a fire-flow test to read the static and residual
pressures.
Test Hydrant
Red Hydrant
3 point connection hydrant
QUESTIONS WITH ACCURATE SOLUTIONS
1. In a scenario where a city is conducting a flow test to evaluate its water
supply system, what would be the significance of using a flow hydrant?
It allows for accurate measurement of water flow, ensuring the
system meets required standards.
It provides a connection point for firefighters during emergencies.
It helps in identifying leaks in the piping system.
It serves as a backup water source for residential areas.
2. Why is it important for mains supplying fire hydrants to have a minimum
pipe size of 6 inches?
A minimum pipe size of 6 inches ensures adequate water flow
and pressure for firefighting purposes.
A minimum pipe size of 6 inches is required for aesthetic reasons.
A minimum pipe size of 6 inches prevents corrosion in the pipes.
A minimum pipe size of 6 inches is necessary for easy installation.
3. If a water supply system is tested at an average pressure of 150 psi during
a hydrostatic test, what implications does this have for the system's
integrity?
The system must be able to withstand pressures above 150 psi
without leaking or failing.
The system is guaranteed to function properly at 150 psi.
The system can only operate safely at 100 psi.
The system's integrity is not affected by the test pressure.
4. What is the primary function of an indicating valve?
, To provide the valve operating condition, open or closed.
To regulate water flow in piping systems.
To prevent backflow in water supply systems.
To measure water pressure in hydrants.
5. What does the variable 'L' represent in the Hydrostatic Testing Allowance
Formula?
Length of the pipe
Diameter of the pipe
Pressure in psi
Safety factor
6. What is the minimum pipe diameter that feeds a hydrants?
6 inches
4 inches
8 inches
5 inches
7. What is the primary purpose of a private fire hydrant?
To supply hose and fire department pumpers with water on
private property.
To provide drinking water to residents.
To drain excess water from the property.
To serve as a decorative feature in landscaping.
8. Describe the process involved in conducting a hydrostatic test on a
piping system.
, The process involves increasing the internal pressure of the
piping system for a specified duration to check for leaks and
ensure integrity.
The process involves draining the system and inspecting for
corrosion.
The process involves flushing the system with water to remove
debris.
The process involves measuring the flow rate of water through the
system.
9. What is the specified height range for post indicator valves above final
grade according to the document?
32 in - 40 in (800 mm to 1000 mm)
24 in - 30 in (600 mm to 750 mm)
40 in - 48 in (1000 mm to 1200 mm)
28 in - 36 in (700 mm to 900 mm)
10. What is the value of "D" in the equation used to size gas piping by
computing the maximum demand quantity?
Demand (maximum cfm)
Inside diameter of the pipe (inches)
Demand (maximum cfh)
Outside diameter for pipe (inches)
11. Fire hydrant used during a fire-flow test to read the static and residual
pressures.
Test Hydrant
Red Hydrant
3 point connection hydrant
