✅ Fire Apparatus Engineer (FAE) – Illinois Exam Questions and Answers
1. What is the minimum pump capacity required for a fire apparatus to be classified as
a pumper by NFPA standards?
Answer:
The minimum pump capacity required is 750 gallons per minute (GPM) at 150 PSI.
Explanation:
According to NFPA 1901, a standard fire pumper must have a minimum pump capacity of
750 GPM. This ensures it can handle the suppression needs for structural and wildland fires.
2. When drafting from a static water source, what is the maximum theoretical lift of
water?
Answer:
The maximum theoretical lift is 33.9 feet at sea level.
Explanation:
Due to atmospheric pressure (14.7 psi at sea level), a perfect vacuum could lift water 33.9
feet. However, practical lifts are generally limited to 20-25 feet due to friction loss and
imperfect vacuum conditions.
3. What is the formula to calculate Net Pump Discharge Pressure (NPDP) when
pumping from a hydrant?
,Answer:
NPDP = PDP - Intake Pressure
Explanation:
This formula is used to determine the actual work the pump is doing. Pump Discharge
Pressure (PDP) includes the pressure from the hydrant, so you subtract the intake to get the
net effort of the pump.
4. What is the friction loss in 100 feet of 2½" hose flowing 250 GPM? (Use standard
formula FL = C × Q² × L; C for 2½" hose = 2)
Answer:
Friction Loss (FL) = 2 × (2.5)² × 1 = 2 × 6.25 = 12.5 psi
Explanation:
● C = 2
● Q = flow rate in hundreds of GPM = = 2.5
● L = length in hundreds of feet = = 1
So, FL = 2 × 6.25 × 1 = 12.5 psi
5. What is the purpose of a relief valve on a fire pump?
,Answer:
To prevent pressure spikes and protect personnel and equipment from over-pressurization.
Explanation:
Relief valves automatically divert excess pressure from the discharge side of the pump
when pressure exceeds a preset limit. This ensures safety and operational consistency during
firefighting operations.
6. How do you calculate the GPM from a smooth bore nozzle? (Use GPM = 29.7 × D² ×
√P)
Answer:
Let’s assume a 1-inch tip and 50 psi nozzle pressure:
GPM = 29.7 × (1)² × √50 = 29.7 × 7.07 ≈ 210 GPM
Explanation:
This equation gives a precise flow rate for a smooth bore nozzle:
● D = diameter in inches
● P = pressure in psi
7. What type of pump is most commonly used on fire apparatus?
, Answer:
Centrifugal pump
Explanation:
Centrifugal pumps are durable, simple in design, and capable of variable flow and pressure,
making them ideal for fire suppression operations.
8. What is cavitation, and how can it be prevented during pump operation?
Answer:
Cavitation is the formation of vapor bubbles due to low inlet pressure, causing damage
when bubbles collapse.
Prevention Methods:
● Maintain proper water supply
● Avoid exceeding draft limits
● Monitor intake pressure closely
Explanation:
Cavitation reduces pump efficiency and can destroy impellers over time.
9. What is the maximum allowable vacuum reading during drafting operations?
1. What is the minimum pump capacity required for a fire apparatus to be classified as
a pumper by NFPA standards?
Answer:
The minimum pump capacity required is 750 gallons per minute (GPM) at 150 PSI.
Explanation:
According to NFPA 1901, a standard fire pumper must have a minimum pump capacity of
750 GPM. This ensures it can handle the suppression needs for structural and wildland fires.
2. When drafting from a static water source, what is the maximum theoretical lift of
water?
Answer:
The maximum theoretical lift is 33.9 feet at sea level.
Explanation:
Due to atmospheric pressure (14.7 psi at sea level), a perfect vacuum could lift water 33.9
feet. However, practical lifts are generally limited to 20-25 feet due to friction loss and
imperfect vacuum conditions.
3. What is the formula to calculate Net Pump Discharge Pressure (NPDP) when
pumping from a hydrant?
,Answer:
NPDP = PDP - Intake Pressure
Explanation:
This formula is used to determine the actual work the pump is doing. Pump Discharge
Pressure (PDP) includes the pressure from the hydrant, so you subtract the intake to get the
net effort of the pump.
4. What is the friction loss in 100 feet of 2½" hose flowing 250 GPM? (Use standard
formula FL = C × Q² × L; C for 2½" hose = 2)
Answer:
Friction Loss (FL) = 2 × (2.5)² × 1 = 2 × 6.25 = 12.5 psi
Explanation:
● C = 2
● Q = flow rate in hundreds of GPM = = 2.5
● L = length in hundreds of feet = = 1
So, FL = 2 × 6.25 × 1 = 12.5 psi
5. What is the purpose of a relief valve on a fire pump?
,Answer:
To prevent pressure spikes and protect personnel and equipment from over-pressurization.
Explanation:
Relief valves automatically divert excess pressure from the discharge side of the pump
when pressure exceeds a preset limit. This ensures safety and operational consistency during
firefighting operations.
6. How do you calculate the GPM from a smooth bore nozzle? (Use GPM = 29.7 × D² ×
√P)
Answer:
Let’s assume a 1-inch tip and 50 psi nozzle pressure:
GPM = 29.7 × (1)² × √50 = 29.7 × 7.07 ≈ 210 GPM
Explanation:
This equation gives a precise flow rate for a smooth bore nozzle:
● D = diameter in inches
● P = pressure in psi
7. What type of pump is most commonly used on fire apparatus?
, Answer:
Centrifugal pump
Explanation:
Centrifugal pumps are durable, simple in design, and capable of variable flow and pressure,
making them ideal for fire suppression operations.
8. What is cavitation, and how can it be prevented during pump operation?
Answer:
Cavitation is the formation of vapor bubbles due to low inlet pressure, causing damage
when bubbles collapse.
Prevention Methods:
● Maintain proper water supply
● Avoid exceeding draft limits
● Monitor intake pressure closely
Explanation:
Cavitation reduces pump efficiency and can destroy impellers over time.
9. What is the maximum allowable vacuum reading during drafting operations?
