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NY Fire Sprinkler practice questions

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Question 1Fire Sprinkler Systems

Under NFPA 13, what is the minimum nominal pipe size for any underground lead-in supplying a sprinkler system riser?

  1. 4 in Correct answer.
  2. 2 in
  3. 1/2 in
  4. 1 in

Explanation

NFPA 13 requires the underground lead-in feeding a sprinkler system to be at least 4 in nominal diameter so it can deliver the system demand and resist damage. Smaller lines are permitted only for certain limited appurtenance connections, not as the main supply.

Question 2Fire Sprinkler Systems

A sprinkler is installed in a location where the maximum ambient ceiling temperature is 150°F. Which temperature rating is the minimum acceptable selection?

  1. 212°F
  2. 135°F
  3. 175°F Correct answer.
  4. 286°F

Explanation

NFPA 13 requires the temperature rating of a sprinkler to be at least 25°F above the maximum expected ceiling temperature, with a minimum rating of 135°F. With a 150°F ceiling, the minimum acceptable rating is 175°F.

Question 3Fire Sprinkler Systems

Which sprinkler orientation discharges water upward to a deflector that spreads the spray downward over the protected area?

  1. Concealed pendent
  2. Sidewall
  3. Upright Correct answer.
  4. Pendent

Explanation

An upright sprinkler has its deflector above the frame, so water is thrown upward against the deflector and distributed downward. Pendent and sidewall designs use different deflector geometry and mounting.

Question 4Fire Sprinkler Systems

What is the minimum clearance required between the deflector of a standard spray upright or pendent sprinkler and the top of combustible storage beneath it?

  1. 18 in Correct answer.
  2. 36 in
  3. 6 in
  4. 12 in

Explanation

NFPA 13 requires at least 18 in of clear space between the sprinkler deflector and the top of combustible storage to allow the spray pattern to develop. Noncombustible storage may be permitted closer.

Question 5Fire Sprinkler Systems

A light hazard occupancy has a design area of 1,500 sq ft and a density of 0.10 gpm/sq ft. What is the minimum sprinkler flow required before hose stream allowance is added?

  1. 150 gpm Correct answer.
  2. 1,500 gpm
  3. 15 gpm
  4. 300 gpm

Explanation

The required sprinkler flow is the density multiplied by the design area: 0.10 gpm/sq ft times 1,500 sq ft equals 150 gpm. Hose stream allowance is added separately to the supply requirement.

Question 6Fire Sprinkler Systems

Which component is installed on a wet pipe system to relieve excess pressure caused by thermal expansion of water?

  1. Relief valve Correct answer.
  2. Check valve
  3. Pressure-reducing valve
  4. Flow switch

Explanation

A relief valve on a wet pipe system discharges water when thermal expansion raises pressure above the system setpoint, protecting components from overpressure. A check valve only prevents backflow and does not relieve pressure.

Question 7Fire Sprinkler Systems

What is the maximum spacing permitted between sprinklers on a branch line for a light hazard, standard spray, unobstructed construction with 1/2 in sprinklers?

  1. 15 ft Correct answer.
  2. 12 ft
  3. 20 ft
  4. 10 ft

Explanation

NFPA 13 permits light hazard sprinkler spacing up to 15 ft for standard spray sprinklers, with the area per sprinkler limited to 225 sq ft. Tighter spacing applies to higher hazard classes.

Question 8Fire Sprinkler Systems

Which type of system is designed so that water is held back by a deluge valve and all sprinklers open simultaneously on activation?

  1. Deluge Correct answer.
  2. Wet pipe
  3. Dry pipe
  4. Preaction

Explanation

A deluge system uses open sprinklers, and the deluge valve releases water to all heads at once when detection activates. Dry pipe and preaction systems use closed sprinklers that operate individually.

Question 9Fire Sprinkler Systems

A dry pipe system protects an unheated area. What is the primary purpose of the air pressure maintained in the system piping?

  1. To speed water delivery to the farthest sprinkler
  2. To provide a pneumatic signal to the fire alarm panel
  3. To prevent freezing of residual water in the pipes
  4. To hold the dry pipe valve closed until a sprinkler operates Correct answer.

Explanation

Air pressure in a dry pipe system keeps the clapper of the dry pipe valve seated against the water supply. When a sprinkler opens and air escapes, the valve trips and water enters the piping.

Question 10Fire Sprinkler Systems

What is the maximum allowable time for water to reach the test connection on a dry pipe system, measured from the time the inspector's test valve is opened?

  1. 30 seconds
  2. 120 seconds
  3. 60 seconds Correct answer.
  4. 90 seconds

Explanation

NFPA 13 requires water to be delivered to the inspector's test connection within 60 seconds of opening the test valve on a dry pipe system. This confirms the system can deliver water promptly.

Question 11Fire Sprinkler Systems

Which feature distinguishes a single-interlock preaction system from a double-interlock preaction system?

  1. Water enters only after both detection and a sprinkler operate
  2. Water enters the piping on detection alone, before any sprinkler operates Correct answer.
  3. The system uses open sprinklers throughout
  4. The system contains no detection devices

Explanation

In a single-interlock preaction system, activation of the detection system alone opens the preaction valve and admits water to the piping while the sprinklers remain closed. A double-interlock system requires both detection and a sprinkler operation.

Question 12Fire Sprinkler Systems

What is the required minimum diameter of the main drain test connection on a wet pipe riser?

  1. 2 in Correct answer.
  2. 1 in
  3. 3 in
  4. 1/2 in

Explanation

NFPA 13 requires the main drain to be at least 2 in in diameter so that a meaningful flow test can be conducted. Smaller sizes are used for auxiliary drains, not the main drain.

Question 13Fire Sprinkler Systems

During a main drain flow test on a wet pipe system, the static pressure is 90 psi and the residual pressure with the drain flowing is 68 psi. What is the pressure drop?

  1. 90 psi
  2. 68 psi
  3. 158 psi
  4. 22 psi Correct answer.

Explanation

The pressure drop is the static reading minus the residual reading: 90 psi minus 68 psi equals 22 psi. This drop indicates the condition of the supply and the riser piping.

Question 14Fire Sprinkler Systems

What is the maximum allowable distance between sprinklers and the end of a branch line in a light hazard occupancy?

  1. Half the allowable sprinkler spacing Correct answer.
  2. One quarter of the allowable sprinkler spacing
  3. The full allowable sprinkler spacing
  4. Twice the allowable sprinkler spacing

Explanation

NFPA 13 limits the distance from the last sprinkler to the end of the branch line to one-half the allowable spacing for that hazard. This ensures coverage near the end of the line.

Question 15Fire Sprinkler Systems

In a hydraulically calculated system, what does the term 'density' represent?

  1. The total flow through the main drain
  2. The friction loss per foot of pipe
  3. The volume of water applied per unit of floor area per unit time Correct answer.
  4. The pressure at the base of the riser

Explanation

Density expresses the rate of water application over the protected area, typically in gpm per square foot. It is multiplied by the design area to determine the required sprinkler flow.

Question 16Fire Sprinkler Systems

Which condition requires the installation of a check valve on a sprinkler system connection to a municipal water supply?

  1. When the system is protected by a dry pipe valve
  2. When the system uses a wet pipe alarm valve
  3. When the sprinkler system serves a single-family dwelling
  4. When the system is supplied from a source that could be contaminated by backflow Correct answer.

Explanation

A check valve is required where backflow could contaminate a potable supply, as with certain connections to municipal mains. It prevents system water from reversing into the public supply.

Question 17Fire Sprinkler Systems

What is the minimum required size of the fire department connection for a sprinkler system?

  1. 2 in
  2. 6 in
  3. 4 in Correct answer.
  4. 1 in

Explanation

NFPA 13 requires the fire department connection to be at least 4 in in size to allow adequate flow from fire department apparatus. Smaller connections cannot supply the system demand.

Question 18Fire Sprinkler Systems

A sprinkler system protects a room with a ceiling slope of 6 in per foot. Which sprinkler arrangement is permitted?

  1. Sprinklers installed level regardless of the slope
  2. Sprinklers installed only at the high point of the roof
  3. Sprinklers omitted entirely because of the slope
  4. Sprinklers installed parallel to the slope with the deflector aligned to the roof pitch Correct answer.

Explanation

For sloped ceilings, NFPA 13 permits sprinklers to be installed with their deflectors parallel to the slope so the spray pattern follows the roof pitch. Level installation is limited to shallow slopes.

Question 19Fire Sprinkler Systems

Which of the following is the correct purpose of the alarm test valve on a wet pipe system?

  1. To measure the static pressure at the riser
  2. To relieve excess pressure from thermal expansion
  3. To drain the system after a flow test
  4. To simulate sprinkler flow and verify that the alarm activates Correct answer.

Explanation

The alarm test valve allows water to flow through the alarm line, simulating a sprinkler operation so the alarm device can be verified. It does not drain the system or relieve pressure.

Question 20Fire Sprinkler Systems

What is the maximum allowable area protected by a single sprinkler in a light hazard occupancy?

  1. 100 sq ft
  2. 130 sq ft
  3. 225 sq ft Correct answer.
  4. 400 sq ft

Explanation

NFPA 13 limits the area per sprinkler to 225 sq ft in light hazard occupancies with standard spray sprinklers. Higher hazard classes require smaller protected areas per sprinkler.

Question 21Fire Sprinkler Systems

A wet pipe system has a 2 in main drain. During the drain test, the static pressure is 80 psi and the residual is 50 psi. Which conclusion is best supported by a 30 psi drop?

  1. The sprinkler heads are oversized for the system
  2. The supply main or riser may be partially obstructed and should be investigated Correct answer.
  3. The system is operating normally and needs no further action
  4. The alarm valve is stuck open

Explanation

A large drop between static and residual pressure during the main drain test suggests a restriction or deteriorated supply. The piping and supply should be investigated to confirm adequate capacity.

Question 22Fire Sprinkler Systems

Which condition would require a dry pipe system rather than a wet pipe system in a protected space?

  1. The space contains flammable liquids
  2. The space is subject to freezing temperatures Correct answer.
  3. The space has a high ceiling
  4. The space is a light hazard occupancy

Explanation

Wet pipe systems are unsuitable where piping may freeze, so a dry pipe system is used to protect unheated spaces. Flammable liquid storage and high ceilings do not by themselves require a dry system.

Question 23Fire Sprinkler Systems

A hydraulic calculation shows the sprinkler demand at 250 gpm and the hose stream allowance at 100 gpm. What total flow must the supply provide?

  1. 250 gpm
  2. 150 gpm
  3. 100 gpm
  4. 350 gpm Correct answer.

Explanation

The total supply requirement is the sprinkler demand plus the hose stream allowance: 250 gpm plus 100 gpm equals 350 gpm. The supply must meet this combined figure.

Question 24Fire Sprinkler Systems

Which arrangement is required when sprinklers are installed in a concealed space with combustible construction and the space exceeds the limits for omission?

  1. Sprinklers must be installed within the concealed space Correct answer.
  2. Sprinklers are installed only at the access opening
  3. Sprinklers may be omitted if the space is small
  4. Sprinklers are replaced by detection devices

Explanation

Where combustible concealed spaces exceed the omission limits in NFPA 13, sprinklers must be installed within the space to control a fire that could develop there. Detection devices do not substitute for sprinkler protection.

Question 25Fire Sprinkler Systems

A sprinkler system uses a backflow preventer that creates a significant pressure loss. How should the hydraulic calculation account for this device?

  1. Assume a fixed 5 psi loss regardless of flow
  2. Deduct the loss from the hose stream allowance
  3. Include the device's pressure loss in the calculation at the design flow Correct answer.
  4. Ignore the loss because it is a plumbing accessory

Explanation

Backflow preventers impose a flow-dependent pressure loss that must be included in the hydraulic calculation at the design flow. Ignoring it can result in inadequate pressure at the sprinklers.

Question 26Fire Sprinkler Systems

On a wet pipe sprinkler system, which device sounds the local waterflow alarm when a sprinkler operates and water flows through the riser?

  1. A pressure relief valve
  2. A dry pipe valve with an accelerator
  3. A water motor gong driven by the flow of water Correct answer.
  4. A pressure-reducing valve at the riser

Explanation

A water motor gong is a mechanical alarm device that operates from the energy of flowing water; when a sprinkler fuses, flow through the alarm line spins the gong, producing a local audible alarm without requiring electrical power.

Question 27Fire Sprinkler Systems

In a wet pipe system, what is the function of the inspector's test connection?

  1. To measure the static pressure at the top of the riser
  2. To flush debris from the branch lines during commissioning
  3. To drain the system after hydrostatic testing
  4. To simulate the flow from a single sprinkler and verify that the alarm activates Correct answer.

Explanation

The inspector's test connection is a valve and orifice arranged to discharge at a rate equivalent to one sprinkler, located at the most remote part of the system; opening it confirms that water reaches the alarm device and that the alarm sounds within the required time.

Question 28Fire Sprinkler Systems

Which sprinkler temperature rating meets an intermediate-temperature specification for a sprinkler installed in a light hazard occupancy with a maximum ambient ceiling temperature of 100°F, away from special heat sources?

  1. 286°F
  2. 135°F
  3. 175°F Correct answer.
  4. 360°F

Explanation

A 175°F sprinkler is in the intermediate-temperature category and meets the stated specification. Ordinary or intermediate-temperature sprinklers may be permitted under these conditions. A 135°F ordinary-temperature sprinkler can also be appropriate at a 100°F maximum ceiling temperature, but it does not meet this question's intermediate-temperature specification.

Question 29Fire Sprinkler Systems

What is the minimum clearance required between the deflector of a standard spray upright sprinkler and the ceiling?

  1. 12 in
  2. 4 in
  3. 18 in
  4. 1 in Correct answer.

Explanation

Standard spray upright sprinklers must be positioned so the deflector is between 1 in and 12 in below the ceiling, with the 1 in minimum ensuring the spray pattern develops properly before striking the ceiling.

Question 30Fire Sprinkler Systems

Which piping arrangement is required for the connection between a sprinkler system riser and a public water main where the system is subject to backflow conditions?

  1. A strainer installed upstream of the riser check valve
  2. A bypass line around the riser control valve
  3. A check valve installed only on the fire department connection
  4. An approved backflow prevention assembly installed in the supply connection Correct answer.

Explanation

Where a sprinkler system could allow contamination to flow back into a potable supply, an approved backflow prevention assembly must be installed in the connection and included in the hydraulic calculation as a pressure loss.

Question 31Fire Sprinkler Systems

What is the purpose of a sprinkler system's auxiliary drain on a trapped section of dry pipe?

  1. To relieve air pressure when the dry pipe valve trips
  2. To remove condensate that collects at low points in the piping Correct answer.
  3. To supply water to the fire department connection
  4. To provide a test point for the waterflow alarm

Explanation

Condensate forms in dry pipe systems as compressed air cools; auxiliary drains at low points and at the low end of trapped sections allow this water to be removed before it freezes or corrodes the piping.

Question 32Fire Sprinkler Systems

Which hanger is required to support sprinkler piping directly at a point where a change in direction occurs?

  1. A flexible coupling
  2. A seismic separation assembly
  3. A hanger located within the permitted distance of the change in direction Correct answer.
  4. A sway brace

Explanation

Piping must be supported so that changes in direction are restrained; hangers are placed within the maximum permitted distance of fittings and direction changes to prevent unsupported loads and stress at the joint.

Question 33Fire Sprinkler Systems

What is the maximum distance permitted between the deflector of a sidewall sprinkler and the wall on which it is mounted for a standard spray sidewall in a light hazard occupancy?

  1. 2 in
  2. 12 in
  3. 18 in
  4. 6 in Correct answer.

Explanation

Standard spray sidewall sprinklers must be positioned with the deflector 4 in to 6 in from the wall surface, and the maximum permitted distance is 6 in to produce the intended spray pattern across the room.

Question 34Fire Sprinkler Systems

A wet pipe system serves a building where the water supply is adequate in pressure but the owner wants the system to be able to deliver water to a fire department connection for supplemental supply. What is the primary purpose of the fire department connection?

  1. To supply the domestic water system during a fire
  2. To allow a pumper to supplement the system's water supply and pressure Correct answer.
  3. To provide a test point for the main drain
  4. To drain the sprinkler system during maintenance

Explanation

A fire department connection lets responding apparatus pump additional water into the sprinkler or standpipe system, supplementing the automatic supply when the demand exceeds what the public main can deliver.

Question 35Fire Sprinkler Systems

A light hazard occupancy has a ceiling 12 ft high and a solid, noncombustible ceiling. What is the maximum protection area permitted for a standard spray sprinkler?

  1. 400 sq ft
  2. 130 sq ft
  3. 225 sq ft
  4. 200 sq ft Correct answer.

Explanation

For light hazard standard spray sprinklers with a 12 ft ceiling height, the maximum protection area per sprinkler is 200 sq ft when the spacing limits and deflector distances are met; higher ceilings reduce the permitted area per sprinkler.

Question 36Fire Sprinkler Systems

A dry pipe system has a capacity of 750 gal and is protected by a dry pipe valve. What is the maximum time permitted for water to reach the test connection after the valve trips, measured from the time the valve opens?

  1. 60 seconds Correct answer.
  2. 30 seconds
  3. 120 seconds
  4. 90 seconds

Explanation

For a dry pipe system, water must reach the test connection within 60 seconds after the dry pipe valve trips, a limit that drives the use of quick-opening devices and adequate air pressure on larger systems.

Question 37Fire Sprinkler Systems

Which arrangement correctly describes a non-interlock preaction system?

  1. The preaction valve opens only when both a detection signal and a sprinkler operate
  2. The preaction valve opens only when a manual pull station is activated
  3. The preaction valve opens only when the supervisory air pressure drops
  4. The preaction valve opens when the detection system operates, admitting water to dry piping before a sprinkler fuses Correct answer.

Explanation

In a non-interlock preaction system, the detection system alone trips the preaction valve, filling the piping with water; the system then functions as a wet system when a sprinkler operates.

Question 38Fire Sprinkler Systems

A wet pipe system has a 2 in main drain. With the drain fully open, the static pressure is 100 psi and the residual pressure is 70 psi. What is the pressure drop?

  1. 30 psi Correct answer.
  2. 100 psi
  3. 70 psi
  4. 170 psi

Explanation

The pressure drop across a main drain test is the difference between static and residual pressure, here 100 psi minus 70 psi, which equals 30 psi; comparing this value with prior test results reveals deterioration in the supply.

Question 39Fire Sprinkler Systems

During a flow test, a pitot reading is taken at the outlet of a 2 in hydrant nozzle. Which factor must be applied to convert the pitot pressure to flow in gallons per minute?

  1. The diameter of the supply main
  2. The static pressure at the hydrant
  3. A discharge coefficient for the nozzle Correct answer.
  4. The elevation of the hydrant above the main

Explanation

Flow from a nozzle is calculated from pitot pressure using the nozzle discharge coefficient along with the nozzle diameter; the coefficient accounts for the specific opening characteristics of the nozzle being tested.

Question 40Fire Sprinkler Systems

A sprinkler system protects a room with a combustible concealed space above a suspended ceiling. What is required for sprinklers in that concealed space when the space contains combustible materials?

  1. Sprinklers may be replaced by smoke detection
  2. Sprinklers must be installed in the concealed space Correct answer.
  3. Sprinklers may be omitted if the ceiling below is noncombustible
  4. Sprinklers are required only if the space exceeds 6 ft in height

Explanation

Combustible concealed spaces of the type that can accumulate fire load and spread fire horizontally require sprinkler protection within the space; omission is permitted only for specific noncombustible or limited-combustible arrangements recognized by the standard.

Question 41Fire Sprinkler Systems

A hydraulic calculation for a sprinkler system must account for a backflow preventer that produces a 10 psi loss at the design flow. How is this loss handled?

  1. It is deducted from the sprinkler discharge density
  2. It is replaced by the elevation loss of the riser
  3. It is ignored because backflow preventers are not flow devices
  4. It is added to the required supply pressure as a fitting loss in the calculation Correct answer.

Explanation

Devices in the supply path, including backflow preventers, must be included in the hydraulic calculation as pressure losses at the design flow, increasing the total required supply pressure.

Question 42Fire Sprinkler Systems

What is the minimum required size of a sprinkler system's main drain connection for a riser with a 4 in supply main?

  1. 2 in Correct answer.
  2. 4 in
  3. 1 in
  4. 3 in

Explanation

The main drain must be at least 2 in for systems with risers of 4 in or larger; smaller risers may use a smaller drain sized per the standard, but the drain must be capable of achieving the flow needed for the test.

Question 43Fire Sprinkler Systems

A dry pipe system in an unheated warehouse must be tested for air tightness. What is the purpose of the air test?

  1. To confirm that the dry pipe valve will trip at the design water pressure
  2. To determine the friction loss through the dry pipe valve
  3. To measure the water delivery time to the test connection
  4. To verify that the piping and fittings will hold the supervisory air pressure without excessive leakage Correct answer.

Explanation

An air test confirms the integrity of the dry piping and its joints under the supervisory air pressure; excessive leakage would allow the system to lose air, cause false trips, or delay water delivery.

Question 44Fire Sprinkler Systems

Which condition would require that a sprinkler system be provided with a control valve and a check valve arranged so the system can be isolated without draining the entire supply?

  1. A system with a single fire department connection
  2. A system connected to a supply that also serves other systems or a combined standpipe Correct answer.
  3. A single riser serving one building with no other connections
  4. A system supplied only by a gravity tank

Explanation

Where a sprinkler system shares a supply with other systems or a combined standpipe, control and check valves are needed so that one system can be isolated for maintenance or repair without interrupting or draining the others.

Question 45Fire Sprinkler Systems

A sprinkler system uses a dry pipe valve with a 6 in riser and a system capacity of 600 gal. Which feature is most important to ensure the water delivery time limit is met?

  1. A larger fire department connection
  2. A water motor gong on the alarm line
  3. A pressure-reducing valve on the riser
  4. An accelerator or quick-opening device on the dry pipe valve Correct answer.

Explanation

Large dry pipe systems can exceed the 60 second water delivery limit because air must escape before water can fill the piping; an accelerator or quick-opening device speeds the drop in air pressure and trips the valve sooner.

Question 46Fire Sprinkler Systems

A hydraulic calculation shows a total sprinkler demand of 300 gpm at the base of the riser and a hose stream allowance of 100 gpm. The water supply curve shows 350 gpm available at 60 psi. What is the correct conclusion?

  1. The supply is adequate because 350 gpm exceeds the sprinkler demand
  2. The supply is adequate because the hose stream allowance is not added to the demand
  3. The supply is inadequate because the total demand of 400 gpm exceeds the available 350 gpm Correct answer.
  4. The supply is inadequate only if the static pressure is below 50 psi

Explanation

The total system demand is the sprinkler demand plus the hose stream allowance, here 400 gpm; comparing that total with the available supply at the required pressure determines adequacy, and 400 gpm exceeds the 350 gpm available.

Question 47Fire Sprinkler Systems

A building has a sloped ceiling with a slope of 8 in per foot. Which sprinkler arrangement is required for standard spray sprinklers in the peak area?

  1. Sprinklers must be positioned so that the deflector is parallel to the slope and within the permitted distance of the peak Correct answer.
  2. Sprinklers may be spaced uniformly across the slope without regard to the peak
  3. Sprinklers must be omitted within 12 in of the peak
  4. Sprinklers must be replaced by sidewall sprinklers along the ridge

Explanation

On steeply sloped ceilings, sprinklers must be oriented so the deflector aligns with the slope and positioned within the permitted distance of the peak, ensuring the spray pattern covers the ridge area where heat collects.

Question 48Fire Sprinkler Systems

A wet pipe system in a parking garage is exposed to freezing temperatures near the overhead door. Which approach best complies with the requirement to protect the piping from freezing while maintaining sprinkler protection?

  1. Drain the entire system during winter months
  2. Reduce the sprinkler density in the exposed area
  3. Install a pressure relief valve on the exposed branch line
  4. Use a dry pipe system or an antifreeze system for the exposed portion Correct answer.

Explanation

Where piping is exposed to freezing, the system must be arranged as a dry pipe, preaction, or listed antifreeze system for that portion, so water is not held in the piping subject to freezing while protection is maintained.

Question 49Fire Sprinkler Systems

A sprinkler system is being designed for a storage occupancy with rack storage. Which factor most directly determines the required sprinkler density and operating area?

  1. The number of fire department connections provided
  2. The commodity classification, storage height, and rack arrangement Correct answer.
  3. The building's construction type alone
  4. The size of the main drain connection

Explanation

Storage design criteria depend on the commodity classification, the height and arrangement of storage, and the rack configuration, which together determine the design density and the number of sprinklers assumed to operate.

Question 50Fire Sprinkler Systems

A riser serves a system where the water supply is a public main with a pressure of 90 psi static. After the backflow preventer and riser losses, the pressure available at the top of the riser is 55 psi. The sprinkler demand requires 50 psi at the base of the riser. What is the correct interpretation?

  1. The system is inadequate because the available pressure at the base is below the demand
  2. The system is adequate because static pressure is always higher than residual pressure
  3. The system is adequate because 55 psi exceeds the 50 psi requirement Correct answer.
  4. The system is inadequate because the backflow preventer must be removed

Explanation

Adequacy is judged by comparing the pressure available at the point of connection with the pressure required by the hydraulic calculation; here 55 psi available exceeds the 50 psi required, so the supply is adequate without removing devices.