I85PREP
⌘ K
CA Fire Sprinkler study materials
CA Fire Sprinkler study resources

CA Fire Sprinkler practice questions

One question at a time. Build your CA Fire Sprinkler understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Sprinkler System Design and Hydraulic Calculations

According to NFPA 13, what is the minimum design density for a light hazard occupancy when the sprinkler system is designed using the density/area method?

  1. 0.10 gpm/ft² Correct answer.
  2. 0.20 gpm/ft²
  3. 0.15 gpm/ft²
  4. 0.05 gpm/ft²

Explanation

NFPA 13 density/area curves begin at 0.10 gpm/ft² for light hazard occupancies over the smallest design area. Heavier hazards require higher densities along the same family of curves. The value is a minimum starting point, not an average.

Question 2Sprinkler System Design and Hydraulic Calculations

A sprinkler discharges 22 gpm at a flowing pressure of 16 psi. What is its K-factor?

  1. 1.4
  2. 8.0
  3. 11.0
  4. 5.5 Correct answer.

Explanation

The discharge formula is Q = K√P, so K = Q/√P. Here √16 = 4, and 22/4 = 5.5. K-factors are expressed in gpm/psi^0.5.

Question 3Sprinkler System Design and Hydraulic Calculations

In hydraulic calculations, the pressure loss through schedule 40 steel pipe is determined primarily by which relationship?

  1. Continuity equation
  2. Darcy-Weisbach equation
  3. Hazen-Williams formula Correct answer.
  4. Bernoulli's equation

Explanation

NFPA 13 permits the Hazen-Williams formula for computing friction loss in water-filled piping. The C-factor varies by pipe material and internal condition. Darcy-Weisbach is used in other engineering contexts but is not the standard for NFPA 13 calculations.

Question 4Sprinkler System Design and Hydraulic Calculations

What is the purpose of the remote area in a density/area design?

  1. It identifies the hydraulically most demanding area for sizing the supply Correct answer.
  2. It defines the area protected by each control valve
  3. It establishes the maximum spacing between branch lines
  4. It locates the sprinkler closest to the riser

Explanation

The remote area is the operating area assumed to be flowing simultaneously during a fire. Hydraulic calculations must show that the water supply can deliver the required density over that area. It is generally the hydraulically most demanding portion of the system.

Question 5Sprinkler System Design and Hydraulic Calculations

A sprinkler has a K-factor of 8.0 and flows at 25 psi. What is its discharge in gpm?

  1. 40 Correct answer.
  2. 50
  3. 64
  4. 20

Explanation

Using Q = K√P, the square root of 25 is 5. Multiplying 8.0 by 5 gives 40 gpm. The K-factor scales discharge with the square root of pressure.

Question 6Sprinkler System Design and Hydraulic Calculations

For a light hazard occupancy, what is the maximum protection area permitted for a standard spray sprinkler?

  1. 100 ft²
  2. 130 ft²
  3. 225 ft² Correct answer.
  4. 400 ft²

Explanation

NFPA 13 limits standard spray sprinklers in light hazard to 225 ft² per sprinkler on a branch line. The limit tightens as the ceiling slope or construction type changes. Spacing along and between branch lines must also be checked.

Question 7Sprinkler System Design and Hydraulic Calculations

Which component provides the required water supply test data used as the basis for hydraulic calculations?

  1. A backflow preventer test report
  2. A pressure gauge on the service main
  3. A fire pump churn test
  4. A flow test at a nearby hydrant Correct answer.

Explanation

A flow test, typically at a hydrant near the connection, establishes static and residual pressure at known flow. Those points define the water supply curve used in calculations. Flow tests must be recent and corrected for seasonal variation.

Question 8Sprinkler System Design and Hydraulic Calculations

Which occupancy classification generally requires the highest design density of the three standard hazard groups?

  1. Ordinary hazard Group 1
  2. Extra hazard Group 1 Correct answer.
  3. Light hazard
  4. Ordinary hazard Group 2

Explanation

Extra hazard occupancies involve high fuel loads or combustible liquids and demand the highest densities. The density/area curves rise progressively from light through ordinary to extra hazard. Within extra hazard, Group 2 is more severe than Group 1.

Question 9Sprinkler System Design and Hydraulic Calculations

A system requires 0.20 gpm/ft² over a 1,500 ft² design area. What is the minimum total required flow?

  1. 300 gpm Correct answer.
  2. 750 gpm
  3. 450 gpm
  4. 150 gpm

Explanation

Required flow equals density multiplied by design area. Here 0.20 gpm/ft² × 1,500 ft² = 300 gpm. This is the minimum demand before adding hose allowance and other adjustments.

Question 10Sprinkler System Design and Hydraulic Calculations

When a dry pipe system is hydraulically calculated, how is the design area typically adjusted relative to a wet system?

  1. It is reduced by half for all occupancies
  2. It is increased to account for the slower water delivery Correct answer.
  3. It remains exactly the same in all cases
  4. It is decreased because dry systems use larger orifices

Explanation

NFPA 13 requires the design area for dry pipe systems to be increased because water delivery is delayed, allowing the fire to grow. The increase is applied to the remote area before calculating demand. Wet systems do not require this increase.

Question 11Sprinkler System Design and Hydraulic Calculations

What does the term 'hose allowance' represent in a sprinkler hydraulic calculation?

  1. Water used to flush the system after testing
  2. The flow needed to fill the dry pipe system
  3. Water reserved for manual hose streams during a fire Correct answer.
  4. The pressure lost through the riser check valve

Explanation

Hose allowance is added to the sprinkler demand to account for manual hose streams that may operate simultaneously. NFPA 13 specifies allowances based on hazard classification. It is added at the base of the riser in the calculation.

Question 12Sprinkler System Design and Hydraulic Calculations

In a tree system, how does water travel from the riser to the most remote sprinkler?

  1. Through cross mains feeding branch lines from a central feed main
  2. Through a looped main that feeds branch lines from both ends
  3. Through a grid of interconnected mains and branch lines
  4. Through a single main with branch lines feeding individual sprinklers Correct answer.

Explanation

A tree system uses a single main that branches out, with branch lines terminating at the most remote point. Water follows one path to each sprinkler. Gridded and looped systems provide multiple paths.

Question 13Sprinkler System Design and Hydraulic Calculations

A branch line has four sprinklers spaced 12 ft apart, with the first sprinkler 12 ft from the cross main. What length of branch line is protected from the cross main to the last sprinkler?

  1. 24 ft
  2. 60 ft
  3. 36 ft
  4. 48 ft Correct answer.

Explanation

The distance from the cross main to the last sprinkler is the sum of the intervals. With four 12 ft intervals (four sprinklers each 12 ft from the previous point or main), the run is 48 ft. Distances are measured centerline to centerline.

Question 14Sprinkler System Design and Hydraulic Calculations

What is the minimum required pressure at the top of the riser for a wet system with a design density of 0.20 gpm/ft² over 1,500 ft², assuming no hose allowance and a calculated end sprinkler pressure of 15 psi?

  1. Exactly 50 psi at the top of the riser
  2. The pressure is not relevant if the flow is adequate
  3. The calculation must show at least the pressure needed to deliver the density over the area Correct answer.
  4. Exactly 15 psi at the base of the riser

Explanation

Hydraulic calculations must demonstrate that the supply can deliver the required density over the design area with adequate pressure at each sprinkler. The end sprinkler pressure is set by the density and spacing, and losses are added back to the source. There is no fixed single pressure value independent of layout.

Question 15Sprinkler System Design and Hydraulic Calculations

Which factor increases the friction loss in a given length of pipe?

  1. Shorter equivalent length
  2. Larger internal diameter
  3. Higher flow velocity Correct answer.
  4. Lower water temperature

Explanation

Friction loss rises with flow velocity, which increases with flow rate and decreases with pipe diameter. The Hazen-Williams formula shows loss proportional to flow raised to about the 1.85 power. Larger diameter and shorter length both reduce loss.

Question 16Sprinkler System Design and Hydraulic Calculations

What is the purpose of balancing a sprinkler system hydraulic calculation?

  1. To reduce the water supply requirement below the code minimum
  2. To equalize the pressure at every sprinkler in the building
  3. To ensure all sprinklers in the design area discharge at or above the required density Correct answer.
  4. To minimize the total pipe size throughout the system

Explanation

Balancing confirms that each sprinkler in the design area receives enough pressure to deliver the required density. The most remote sprinkler is typically the least favored, so calculations start there and work back. It does not require identical pressure at every head.

Question 17Sprinkler System Design and Hydraulic Calculations

For an ordinary hazard Group 1 occupancy, which design density is commonly used with a 1,500 ft² area?

  1. 0.20 gpm/ft²
  2. 0.15 gpm/ft² Correct answer.
  3. 0.30 gpm/ft²
  4. 0.10 gpm/ft²

Explanation

Ordinary hazard Group 1 typically uses 0.15 gpm/ft² over 1,500 ft² on the density/area curves. The area may vary with the density selected along the curve. Higher densities correspond to smaller areas on the same curve.

Question 18Sprinkler System Design and Hydraulic Calculations

A sprinkler discharges 30 gpm at 36 psi. What K-factor does this indicate?

  1. 5.0 Correct answer.
  2. 8.0
  3. 10.0
  4. 6.0

Explanation

K = Q/√P. The square root of 36 is 6, and 30 divided by 6 equals 5.0. This K-factor is typical of a small-orifice sprinkler.

Question 19Sprinkler System Design and Hydraulic Calculations

Why is the elevation difference between the supply and the highest sprinkler included in hydraulic calculations?

  1. It adds or subtracts pressure at a rate of about 0.433 psi per foot of water Correct answer.
  2. It sets the maximum spacing between branch lines
  3. It determines the K-factor of the sprinkler
  4. It changes the density requirement for the occupancy

Explanation

Each foot of elevation change in water produces about 0.433 psi of pressure change. When sprinklers are above the supply, pressure must be added to overcome the elevation. This term is added to friction losses in the calculation.

Question 20Sprinkler System Design and Hydraulic Calculations

What role does a fire pump play in a sprinkler system hydraulic calculation?

  1. It boosts pressure to meet the demand when the supply is insufficient Correct answer.
  2. It eliminates friction loss in the piping
  3. It reduces the required design density
  4. It replaces the need for a water supply flow test

Explanation

A fire pump adds pressure to the system when the available supply cannot meet the calculated demand. The pump curve must be matched to the system demand curve. The pump does not change the required density or eliminate piping losses.

Question 21Sprinkler System Design and Hydraulic Calculations

A system has a required flow of 400 gpm at 60 psi at the base of the riser. The supply flow test shows 500 gpm at 55 psi. What does this indicate?

  1. The density can be reduced to compensate
  2. The supply is insufficient and a pump or other improvement is needed Correct answer.
  3. The hose allowance can be ignored
  4. The supply is adequate with a large margin

Explanation

The available pressure at the required flow is below the demand pressure, so the supply cannot meet the demand. A fire pump, larger main, or other upgrade is required. Flow and pressure must both be satisfied at the same point.

Question 22Sprinkler System Design and Hydraulic Calculations

In a gridded piping system, why might the hydraulic calculation be more complex than for a tree system?

  1. The pipe sizes are always larger in a grid
  2. Water can reach a sprinkler through multiple paths, so flows must be balanced at each junction Correct answer.
  3. Grids do not require a remote area analysis
  4. The design density is higher for grids

Explanation

In a grid, water may travel to each sprinkler by more than one route, so flows divide at junctions according to resistance. Balancing the network requires iterative calculation. Tree systems have a single path to each sprinkler, simplifying the analysis.

Question 23Sprinkler System Design and Hydraulic Calculations

Which adjustment is required when the design area for a dry pipe system is calculated for a light hazard occupancy?

  1. Use the wet system area without modification
  2. Decrease the remote area to reflect faster trip times
  3. Increase the remote area by the factor specified for dry systems Correct answer.
  4. Double the design density instead of increasing the area

Explanation

NFPA 13 requires the remote area for dry systems to be increased to account for delayed water delivery. The increase is applied to the area, not to the density. Density remains tied to the hazard classification.

Question 24Sprinkler System Design and Hydraulic Calculations

A sprinkler with a K-factor of 11.2 flows at 25 psi. What is its approximate discharge?

  1. 56 gpm Correct answer.
  2. 112 gpm
  3. 44 gpm
  4. 28 gpm

Explanation

Q = K√P, and the square root of 25 is 5. Multiplying 11.2 by 5 gives 56 gpm. This K-factor is typical of a large-orifice sprinkler.

Question 25Sprinkler System Design and Hydraulic Calculations

Why must the hydraulically most remote sprinkler be identified when multiple branch lines serve the design area?

  1. It typically requires the highest pressure to deliver the required density Correct answer.
  2. It sets the hose allowance value
  3. It determines the K-factor for the entire system
  4. It is always the physically closest to the riser

Explanation

The most remote sprinkler generally has the greatest accumulated friction and elevation losses, so it needs the most pressure to achieve the required density. Calculations start there and work back to the source. The most remote point is not always the physically closest.

Question 26Sprinkler System Design and Hydraulic Calculations

In a wet-pipe sprinkler system, which pipe section runs horizontally and directly feeds the individual sprinklers?

  1. The cross main
  2. The feed main
  3. The riser
  4. The branch line Correct answer.

Explanation

The branch line is the smallest horizontal pipe in the system and carries water directly to the individual sprinklers spaced along it. Cross mains feed the branch lines, risers run vertically, and feed mains supply the cross mains.

Question 27Sprinkler System Design and Hydraulic Calculations

What is the primary purpose of a hydraulic calculation for a sprinkler system?

  1. To determine the number of sprinklers needed for an occupancy
  2. To confirm the supply can deliver the required density and pressure to the design area Correct answer.
  3. To estimate the total installed cost of the piping
  4. To select the color and temperature rating of each sprinkler

Explanation

Hydraulic calculations demonstrate that the available water supply can deliver the required design density at adequate pressure to the most remote sprinklers in the design area. They account for flow demand, friction loss, and elevation changes throughout the system.

Question 28Sprinkler System Design and Hydraulic Calculations

A sprinkler has a K-factor of 8.0 and is discharging at 16 psi. What is the approximate discharge in gallons per minute?

  1. 16 gpm
  2. 128 gpm
  3. 32 gpm Correct answer.
  4. 64 gpm

Explanation

Discharge is found from Q = K times the square root of the pressure. The square root of 16 psi is 4, and 8.0 times 4 equals 32 gpm. This relationship lets the designer convert pressure at a sprinkler into flow for the calculation.

Question 29Sprinkler System Design and Hydraulic Calculations

Which term describes the vertical distance between the water supply reference point and the highest sprinkler in the system?

  1. Friction loss
  2. Back pressure
  3. Elevation loss Correct answer.
  4. Velocity head

Explanation

Elevation loss reflects the pressure needed to lift water to the highest sprinkler, equal to about 0.433 psi per foot of rise for water. It is added to the friction and pressure requirements when the supply is below the sprinkler.

Question 30Sprinkler System Design and Hydraulic Calculations

A designer is calculating friction loss in a schedule 40 steel pipe. Which change will increase the friction loss for the same flow?

  1. Increasing the pipe diameter
  2. Shortening the pipe run
  3. Using a smaller nominal pipe diameter Correct answer.
  4. Reducing the flow rate through the pipe

Explanation

Friction loss rises sharply as pipe diameter decreases because velocity increases and the resistance per unit length grows. The Hazen-Williams relationship shows loss is inversely related to a high power of the internal diameter.

Question 31Sprinkler System Design and Hydraulic Calculations

A sprinkler system protects an ordinary hazard occupancy using a design density of 0.15 gpm/ft² over a 1,500 ft² area. What is the minimum required flow at the base of the riser before hose allowance?

  1. 150 gpm
  2. 225 gpm Correct answer.
  3. 100 gpm
  4. 300 gpm

Explanation

Required sprinkler flow equals design density multiplied by the design area. Multiplying 0.15 gpm/ft² by 1,500 ft² gives 225 gpm. Hose allowance would be added separately to the total supply demand.

Question 32Sprinkler System Design and Hydraulic Calculations

Why is the design area extended along branch lines rather than concentrated on a single cross main in a tree system?

  1. Because the remote area is assumed to open with sprinklers distributed along branch lines near the cross main Correct answer.
  2. Because branch lines are always larger than cross mains
  3. Because cross mains carry no water during a fire
  4. Because only sprinklers on one branch line can ever operate at once

Explanation

The design area represents a plausible cluster of operating sprinklers, and in a tree system this cluster is typically taken along branch lines starting at the most remote cross main. This distribution reflects how fire growth opens nearby heads.

Question 33Sprinkler System Design and Hydraulic Calculations

How does a looped or gridded piping arrangement affect the hydraulic calculation compared with a tree system?

  1. Only the single longest path is calculated
  2. The design area is automatically reduced by half
  3. Water can reach a sprinkler by more than one path, so flows must be balanced at each junction Correct answer.
  4. Friction loss is ignored because the loops reduce resistance

Explanation

In a gridded system, flow splits and recombines, so the calculation must solve for the flow distribution at each junction to satisfy equal pressure loss along parallel paths. This makes the analysis iterative and more complex than a simple tree.

Question 34Sprinkler System Design and Hydraulic Calculations

What does a water supply flow test curve describe for hydraulic calculation purposes?

  1. The required inspection frequency for the system
  2. The number of sprinklers on each branch line
  3. The color coding of the sprinkler heads
  4. Available flow and residual pressure at the test point across a range of flows Correct answer.

Explanation

A flow test records static and residual pressure at measured flows, and these points define the available supply curve. The designer compares the system demand point against this curve to confirm adequacy.

Question 35Sprinkler System Design and Hydraulic Calculations

A sprinkler with a K-factor of 5.6 must discharge 28 gpm. What pressure is required at the sprinkler?

  1. 50 psi
  2. 5 psi
  3. 25 psi Correct answer.
  4. 100 psi

Explanation

Rearranging Q = K times the square root of P gives P equal to (Q divided by K) squared. Dividing 28 by 5.6 gives 5, and squaring 5 gives 25 psi. This pressure becomes the starting point for the remote-area calculation.

Question 36Sprinkler System Design and Hydraulic Calculations

Why is the hose allowance added to the sprinkler demand when sizing the water supply?

  1. Because hose streams may operate at the same time as the sprinklers and draw from the same supply Correct answer.
  2. Because hose allowance corrects for pipe friction errors
  3. Because hose lines replace the sprinkler demand during a fire
  4. Because hose allowance accounts for water used in testing

Explanation

Hose allowance represents the flow that fire department hose lines may draw concurrently with the sprinkler system. Adding it to the sprinkler demand ensures the supply can satisfy both without starving the sprinklers.

Question 37Sprinkler System Design and Hydraulic Calculations

A dry pipe system is being hydraulically calculated. How is the design area generally treated compared with a wet system of the same occupancy?

  1. It is replaced by the hose allowance
  2. It is increased to account for the larger number of heads expected to open Correct answer.
  3. It is left identical in all cases
  4. It is decreased because dry systems react faster

Explanation

Dry pipe systems deliver water more slowly because air must first be expelled, allowing more sprinklers to open before water arrives. The design area is therefore increased by a specified percentage to reflect the larger operating area.

Question 38Sprinkler System Design and Hydraulic Calculations

A designer needs to confirm that a proposed system meets demand at the most remote area. Which comparison is made?

  1. The number of sprinklers is compared with the hose allowance
  2. The system demand point is plotted against the available supply curve to confirm supply exceeds demand Correct answer.
  3. The static pressure alone is compared with the sprinkler pressure rating
  4. The pipe volume is compared with the design area

Explanation

The calculated system demand, expressed as flow at a required pressure, is plotted on the same graph as the supply flow test curve. If the demand point falls below and left of the supply curve, the supply is adequate.

Question 39Sprinkler System Design and Hydraulic Calculations

In a hydraulically calculated system, why must the pressure at each operating sprinkler in the design area be evaluated rather than assuming uniform flow?

  1. Because all sprinklers always discharge the same flow by code
  2. Because pressure varies along the branch line, so each sprinkler discharges a different amount Correct answer.
  3. Because only the end sprinkler matters in the calculation
  4. Because friction loss increases pressure toward the end of the line

Explanation

Pressure drops along the piping as water flows, so sprinklers nearer the supply see higher pressure and discharge more than those farther away. The calculation must sum the actual discharge of each head to obtain a correct total demand.

Question 40Sprinkler System Design and Hydraulic Calculations

A system requires 500 gpm at 70 psi at the base of the riser. A supply test shows 600 gpm available at 60 psi. What does this indicate about the supply?

  1. The supply is adequate because the static pressure is higher than 70 psi
  2. The supply is inadequate only if the flow is below 500 gpm
  3. The supply is adequate because the available flow exceeds the required flow
  4. The supply is inadequate because the available pressure at the required flow is below the demand pressure Correct answer.

Explanation

Adequacy requires that the supply provide at least the required flow at the required pressure simultaneously. Here the supply delivers 600 gpm but only at 60 psi, which is below the 70 psi demand, so the supply falls short.

Question 41Water Supply, Standpipes, and Fire Pumps

According to NFPA 13, what is the minimum residual pressure required at the most remote sprinkler when the design area is supplied by a wet pipe system with a density of 0.15 gpm/ft² or greater?

  1. 10 psi (0.69 bar)
  2. 7 psi (0.48 bar) Correct answer.
  3. 15 psi (1.03 bar)
  4. 20 psi (1.38 bar)

Explanation

NFPA 13 sets a minimum residual pressure of 7 psi at the hydraulically most remote sprinkler for most wet systems. Higher minimums apply to dry systems and certain special designs, but the baseline wet-system figure is 7 psi.

Question 42Water Supply, Standpipes, and Fire Pumps

A fire pump is being installed with a suction supply that can provide adequate pressure under all flow conditions. Which pump type is generally the most appropriate choice?

  1. Vertical in-line centrifugal pump
  2. Vertical turbine pump
  3. Positive displacement pump
  4. Horizontal split-case centrifugal pump Correct answer.

Explanation

A horizontal split-case centrifugal pump is commonly selected when a reliable positive suction pressure exists because it is efficient and easy to maintain. Vertical turbine pumps are used when suction comes from a well or below-grade source.

Question 43Water Supply, Standpipes, and Fire Pumps

What is the primary purpose of a standpipe system in a building?

  1. To pre-wet exterior walls during exposure fires
  2. To maintain domestic water pressure during peak demand
  3. To provide a means for firefighting personnel to attach hose lines at various levels Correct answer.
  4. To automatically suppress fires in concealed spaces

Explanation

Standpipe systems provide piping and outlets so firefighters can connect hose lines on upper floors or at remote locations. This eliminates the need to stretch hose from the street level up through the building.

Question 44Water Supply, Standpipes, and Fire Pumps

In a wet standpipe system, what component keeps the piping filled with water under pressure at all times?

  1. A constant source of pressure such as a domestic or fire supply Correct answer.
  2. A dry pipe valve
  3. A check valve
  4. A pressure-regulating valve

Explanation

A wet standpipe is connected to a pressurized water supply so the piping stays full and ready. The pressure source may be a public main, a fire pump, or a gravity tank.

Question 45Water Supply, Standpipes, and Fire Pumps

Which NFPA standard governs the installation of stationary fire pumps?

  1. NFPA 13
  2. NFPA 14
  3. NFPA 25
  4. NFPA 20 Correct answer.

Explanation

NFPA 20 is the standard for the installation of stationary pumps for fire protection. It covers pump selection, drivers, controllers, and acceptance testing.

Question 46Water Supply, Standpipes, and Fire Pumps

What is the minimum required capacity of the water supply for a sprinkler system design?

  1. The sprinkler demand alone, without any hose allowance
  2. The sprinkler demand plus the required hose stream allowance Correct answer.
  3. Only the hose stream allowance
  4. Only the domestic demand plus 100 gpm

Explanation

The water supply must satisfy the sprinkler system demand plus the hose stream allowance required by the applicable standard. Both components are added when analyzing the available supply against demand.

Question 47Water Supply, Standpipes, and Fire Pumps

What does a fire pump churn test measure?

  1. Pump discharge at zero flow Correct answer.
  2. Pump efficiency at rated flow
  3. Pump suction pressure under maximum demand
  4. Pump flow at 150 percent of rated capacity

Explanation

A churn test operates the pump at zero flow to measure shutoff pressure and verify mechanical condition. It is part of the annual pump flow test sequence.

Question 48Water Supply, Standpipes, and Fire Pumps

Which type of standpipe is intended for use by building occupants as well as firefighters and is typically kept wet?

  1. Class I
  2. Class II Correct answer.
  3. Class III
  4. Manual dry

Explanation

Class II standpipes provide 1½-inch hose stations intended for occupant use and are normally wet. Class I systems serve fire department use with larger connections.

Question 49Water Supply, Standpipes, and Fire Pumps

A sprinkler system has a required flow of 850 gpm at 65 psi at the base of the riser. The hose stream allowance is 250 gpm. What total flow must the water supply be capable of providing?

  1. 600 gpm
  2. 1,100 gpm Correct answer.
  3. 1,350 gpm
  4. 850 gpm

Explanation

The total supply requirement equals the sprinkler demand plus the hose stream allowance. Adding 850 gpm and 250 gpm gives 1,100 gpm.

Question 50Water Supply, Standpipes, and Fire Pumps

A fire pump has a rated capacity of 1,000 gpm. During a flow test, what flow rate should be used to verify performance at 150 percent of rated capacity?

  1. 1,500 gpm Correct answer.
  2. 2,000 gpm
  3. 1,150 gpm
  4. 1,000 gpm

Explanation

NFPA 20 requires testing at 150 percent of rated capacity to confirm the pump can deliver overload flow. Multiplying 1,000 gpm by 1.5 yields 1,500 gpm.