7.1.1* When pressure-regulating devices are used, they shall be approved for installation within the maximum and minimum anticipated flow conditions.

7.2* Pressure Limitation.

7.2.1 The maximum pressure at any point in the system at any time shall not exceed 350 psi (24 bar).

7.2.2 Express mains supplying higher standpipe zones shall be permitted to be designed with pressures in excess of 350 psi (24 bar) in accordance with their materials listings or as approved by the AHJ.

7.2.2.1 Where express mains supply higher standpipe zones, there shall be no hose outlets on any portion of the system where the pressure exceeds 350 psi (24 bar).

7.2.3* Maximum Pressure at Hose Connections.

7.2.3.1 Where the residual pressure at a 11⁄2 in. (40 mm) outlet on a hose connection available for trained personnel use exceeds 100 psi (6.9 bar), an approved pressure-regulating device shall be provided to limit the residual pressure at the flow required by Section 7.10 to 100 psi (6.9 bar).

7.2.3.2* Where the static pressure at a hose connection exceeds 175 psi (12.1 bar), an approved pressure-regulating device shall be provided to limit static and residual pressures at the outlet of the hose connection to 100 psi (6.9 bar) for 11⁄2 in. (40 mm) hose connections available for trained personnel use and 175 psi (12.1 bar) for other hose connections.

7.2.3.3 The pressure on the inlet side of the pressureregulating device shall not exceed the rated working pressure of the device.
7.2.4* When system pressure-regulating devices are used in lieu of providing separate pumps, multiple zones shall be permitted to be supplied by a single pump and pressure-regulating device (s) under the following conditions:
(1) Pressure-regulating device(s) shall be permitted to control pressure in the lower zone(s).
(2) A method to isolate the pressure-regulating device(s) shall be provided for maintenance and repair.
(3) Regulating devices shall be arranged so that the failure of any single device does not allow pressure in excess of 175 psi (12.1 bar) to more than two hose connections.
(4) An equally sized bypass around the pressure-regulating device(s), with a normally closed control valve, shall be installed.
(5) Pressure-regulating device(s) shall be installed not more than 7 ft 6 in. (2.31 m) above the floor.
(6) The pressure-regulating device shall be provided with inlet and outlet pressure gauges.
(7) The fire department connection(s) shall be connected to the system side of the outlet isolation valve.
(8) The pressure-regulating device shall be provided with a pressure relief valve in accordance with the manufacturer’s recommendations.
(9) Remote monitoring and supervision for detecting high pressure failure of the pressure-regulating device shall be provided in accordance with NFPA 72, National Fire Alarm and Signaling Code.

7.3 Locations of Hose Connections.

7.3.1* General.

7.3.1.1 Hose connections and hose stations shall be unobstructed and shall be located not less than 3 ft (0.9 m) or more than 5 ft (1.5 m) above the floor.

7.3.1.2 The hose connection shall not be obstructed by the closed or open door or other objects on the landing.

7.3.2* Class I Systems. Class I systems shall be provided with 21⁄2 in. (65 mm) hose connections in the following locations:
(1) At the main floor landing in exit stairways
(2) On each side of the wall adjacent to the exit openings of horizontal exits
(3) In other than covered mall buildings, in each exit passageway at the entrance from the building areas into the passageway
(4) In covered mall buildings, at the entrance to each exit passageway or exit corridor, and at the interior side of public entrances from the exterior to the mall
(5)*At the highest landing of stairways with stairway access to a roof, or on roofs with a slope of less than 4 in 12 where stairways do not access the roof

7.3.2.1 Hose connections shall be permitted to be located at the highest intermediate landings between floor levels in exit stairways where requried by the AHJ.

7.3.2.2* Where the most remote portion of a nonsprinklered floor or story is located in excess of 150 ft (45.7 m) of travel distance from a required exit containing or adjacent to a hose connection or the most remote portion of a sprinklered floor or story is located in excess of 200 ft (61 m) of travel distance from a required exit containing or adjacent to a hose connection, additional hose connections shall be provided, in approved locations, where required by the local fire department or the AHJ.

7.3.3* Class II Systems.

7.3.3.1 Class II systems shall be provided with 11⁄2 in. (40 mm) hose stations so that all portions of each floor level of the building are within 130 ft (39.7 m) of a hose connection provided with 11⁄2 in. (40 mm) hose or within 120 ft (36.6 m) of a hose connection provided with less than 11⁄2 in. (40 mm) hose.

7.3.3.2 Distances shall be measured along a path of travel originating at the hose connection.

7.3.4 Class III Systems. Class III systems shall be provided with hose connections as required for both Class I and Class II systems.

7.3.4.1 Where the building is protected throughout by an approved automatic sprinkler system in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems, or NFPA 13R, Standard for the Installation of Sprinkler Systems in Residential Occupancies up to and Including Four Stories in Height, Class II hose stations for use by trained personnel shall not be required, subject to the approval of the local fire department and the AHJ, provided that each Class I hose connection is 21⁄2 in. (65 mm) and is equippedwith a 21⁄2 in. × 11⁄2 in. (65 mm × 40 mm) reducer and a cap attached with a chain.

7.3.4.1.1 The 130 ft (39.7 m) travel distance limitation shall not apply to Class III systems.

7.3.4.1.2 For Class III systems installed without hose, the flow, pressure, and duration requirements shall be as specified for Class I systems.

7.4 Number of Standpipes. Separate standpipes shall be provided in each required exit stairway.

7.5* Interconnection of Standpipes.

7.5.1 Where two or more standpipes are installed in the same building or section of building, they shall be interconnected.

7.5.2 Where standpipes are supplied by tanks located at the top of the building or zone, the following criteria shall be met:
(1) The standpipes also shall be interconnected at the top.
(2) Check valves shall be installed at the base of each standpipe to prevent circulation.

7.6 Minimum Sizes for Standpipes and Branch Lines.

7.6.1 Class I and Class III standpipes shall be at least 4 in. (100 mm) in size.

7.6.2 Standpipes that are part of a combined system shall be at least 6 in. (150 mm) in size.

7.6.3 Where the building is protected throughout by an approved automatic sprinkler system in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems, or NFPA13R, Standard for the Installation of Sprinkler Systems in Residential Occupancies up to and Including Four Stories in Height, the minimum standpipe size shall be 4 in. (100 mm) for systems hydraulically designed in accordance with 7.8.1.

7.6.4 Branch lines shall be sized based on the hydraulic criteria established in Section 7.8 and Section 7.10 but not less than 21⁄2 in. (65 mm).

7.7 System Design and Sizing of Pipe for Delivery of System Demand.

7.7.1 Class I and Class III standpipe systems shall be designed so that the system demand can be supplied by each fire department connection, which is provided in accordance with Section 7.12.

7.7.2 Where an automatic or semiautomatic water supply is required for a Class I, II, or III standpipe system by Section 5.4, the standpipe system shall be designed so that the system demand can be independently supplied by the attached water supply and each fire department connection provided on the system.

7.7.3 Where a manual system is permitted by Section 5.4 and an attached water supply is provided to supply an automatic sprinkler system or to maintain water in a wet system, the attached water supply shall not be required to satisfy the standpipe system demand.

7.7.4 When determining the system demand to be supplied by the fire department at the fire department connection, the local fire department shall be consulted regarding the water supply available from a fire department pumper.

7.8* Minimum and Maximum Pressure Limits.

7.8.1 Minimum Design Pressure for Hydraulically Designed Systems. Hydraulically designed standpipe systems shall be designed to provide the waterflow rate required by Section 7.10 at a minimum residual pressure of 100 psi (6.9 bar) at the outlet of the hydraulically most remote 21⁄2 in. (65 mm) hose connection and 65 psi (4.5 bar) at the outlet of the hydraulically most remote 11⁄2 in. (40 mm) hose station.

7.8.1.1* Manual standpipe systems shall be designed to provide 100 psi (6.9 bar) at the topmost outlet with the calculations terminating at the fire department connection.

7.9* Standpipe System Zones.

7.9.1 Except as permitted by 7.2.4, each standpipe system zone shall be provided with a separate pump.

7.9.1.1 The use of pumps arranged in series to meet the requirements of 7.9.1 shall be permitted.

7.9.1.2 Pumps that are arranged in series shall be permitted to be, but are not required to be, located on the same level.

7.9.2 Each zone above the low zone shall have two or more separate and direct supply pipes sized to automatically and independently supply the flow and pressure requirements of Sections 7.8 and 7.10.

7.9.2.1 Standpipes from the lower zone shall be permitted to be used to serve as automatic and independent supplies to upper zones.

7.9.3* For systems with two or more zones in which any portion of the higher zones cannot be supplied by means of fire department pumpers through a fire department connection, an auxiliary means of supply in the form of high-level water storage with additional pumping equipment or other means acceptable to the AHJ shall be provided.

7.10 Flow Rates.

7.10.1 Class I and Class III Systems.

7.10.1.1* Flow Rate.

7.10.1.1.1 For Class I and Class III systems, the minimum flow rate for the hydraulically most remote standpipe shall be 500 gpm (1893 L/min), through two 21⁄2 in. (65 mm) outlets at one location, and the calculation procedure shall be in accordance with 7.10.1.2.

7.10.1.1.2* Where a horizontal standpipe on a Class I or Class III system supplies three or more hose connections on any floor, the minimum flow rate for the hydraulically most demanding horizontal standpipe shall be 750 gpm (2840 L/min), and the calculation procedure shall be in accordance with 7.10.1.2.2.

7.10.1.1.3 The minimum flow rate for additional standpipes shall be 250 gpm (946 L/min) per standpipe for buildings with floor areas that do not exceed 80,000 ft2 (7432 m2) per floor. For buildings that exceed 80,000 ft2 (7432m2) per floor, the minimum flow rate for the additional standpipes shall be 500 gpm (1893 L/min) for the second standpipe and 250 gpm (946 L/min) for the third standpipe if the additional flow is required for an unsprinklered building.

7.10.1.1.4 Flow rates for combined systems shall be in accordance with 7.10.1.3.

7.10.1.1.5 The maximum flow rate shall be 1000 gpm (3785 L/ min) for buildings that are sprinklered throughout, in accordance with NFPA13, Standard for the Installation of Sprinkler Systems, and 1250 gpm (4731 L/min) for buildings that are not sprinklered throughout, in accordance with NFPA 13.

7.10.1.2* Hydraulic Calculation Requirements.

7.10.1.2.1 Hydraulic calculations and pipe sizes for each standpipe shall be based on providing 250 gpm (946 L/min) at the two hydraulically most remote hose connections on the standpipe and at the topmost outlet of each of the other standpipes at the minimum residual pressure required by Section 7.8.

7.10.1.2.1.1* Where a standpipe system has risers that terminate at different floor levels, separate hydraulic calculations shall be performed for the standpipes that exist on each level. In each case, flow shall be added only for standpipes that exist on the floor level of the calculations.

7.10.1.2.2 Where a horizontal standpipe on a Class I and Class III system supplies three or more hose connections on any floor, hydraulic calculations and pipe sizes for each standpipe shall be based on providing 250 gpm (946 L/min) at the three hydraulically most remote hose connections on the standpipe and at the topmost outlet of each of the other standpipes at the minimum residual pressure required by Section 7.8.

7.10.1.2.3* Common supply piping shall be calculated and sized to provide the required flow rate for all standpipes connected to such supply piping, with the total not to exceed the maximum flow demand in 7.10.1.1.5.

7.10.1.2.4 Flows from additional standpipes as required by

7.10.1.1 shall not be required to be balanced to the higher pressure at the point of connection.

7.10.1.3 Combined Systems.

7.10.1.3.1 For a building protected throughout by an approved automatic sprinkler system, the system demand established by Section 7.7 and 7.10.1 also shall be permitted to serve the sprinkler system.

7.10.1.3.1.1 Where the sprinkler system water supply requirement, including the hose stream allowance as determined in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems, exceeds the system demand established by Section 7.7 and 7.10.1, the larger of the two values shall be provided.

7.10.1.3.1.2 A separate sprinkler demand shall not be required.

7.10.1.3.2 For a combined system in a building equipped with partial automatic sprinkler protection, the flow rate required by 7.10.1 shall be increased by an amount equal to the hydraulically calculated sprinkler demand or 150 gpm (568 L/min) for light hazard occupancies, or by 500 gpm (1893 L/min) for ordinary hazard occupancies, whichever is less.

7.10.2 Class II Systems.

7.10.2.1 Minimum Flow Rate.

7.10.2.1.1 For Class II systems, the minimum flow rate for the hydraulically most remote hose connection shall be 100 gpm (379 L/min).

7.10.2.1.2 Additional flow shall not be required where more than one hose connection is provided.

7.10.2.2 Hydraulic Calculation Requirements.

7.10.2.2.1 Hydraulic calculations and pipe sizes for each standpipe shall be based on providing 100 gpm (379 L/min) at the hydraulically most remote hose connection on the standpipe at the minimum residual pressure required by Section 7.8.

7.10.2.2.2 Common supply piping serving multiple standpipes shall be calculated and sized to provide 100 gpm (379 L/min).

7.10.3 Maximum Flow Rates for Individual Connections.

7.10.3.1 The maximum flow required from a 21⁄2 in. (65 mm) hose connection shall be 250 gpm (946 L/min).

7.10.3.2 The maximum flow required from a 11⁄2 in. (40 mm) hose connection shall be 100 gpm (379 L/min).

7.10.4 Sprinkler System Hose Demand. Sprinkler system hose demand in fully sprinklered buildings shall not be required to be added to standpipe calculations.

7.11* Drains and Test Riser.

7.11.1 A permanently installed drain riser shall be provided adjacent to each standpipe equipped with pressure-regulating devices to facilitate tests of each device. The drain shall be sized large enough to handle the full flow required from the largest pressure-regulating device but shall not be less than the following:
(1) The size of the discharge outlet of the pressure-regulating device for devices that are greater than 21⁄2 in. (65 mm) in size
(2) 3 in. (80 mm) to facilitate testing of 21⁄2 in. (65 mm) pressure-regulating devices
(3) 2 in. (50 mm) to facilitate testing of 11⁄2 in. (40 mm) pressure-regulating devices

7.11.1.1 The drain riser shall be equipped with tees that are of the same size as the discharge outlets of the pressureregulating devices to be tested with internal threaded swivel fittings having NHS threads, as specified in NFPA 1963, Standard for Fire Hose Connections, with plugs, and shall be located on at least every other floor.

7.11.1.2 Each drain riser shall terminate with a full-size elbow to grade or receptor that will receive the full flow from the drain riser.

7.11.1.3 Where drain risers are interconnected and run to a common discharge point, all piping shall be sized for the combined flow.

7.11.1.4 Where local fire department hose threads do not conform to NFPA 1963, Standard for Fire Hose Connections, the fire department shall designate the hose threads to be used.

7.11.2 Auxiliary Drains. Standpipe systems shall be provided with a means of draining.

7.11.2.1 Auxiliary drains shall be installed in accordance with NFPA13, Standard for the Installation of Sprinkler Systems, where a change in piping direction results in trapped sections of pipe.

7.11.2.2 A drain valve and piping, located at the lowest point of the standpipe piping downstream of the isolation valve, shall be arranged to discharge water at an approved location.

7.11.2.3 Sizing shall be as specified in Table 7.11.2.3.

7.11.3 Main Drain Test Connections. See Figure 7.11.3.

7.11.3.1 Main drain test connections shall be provided at locations that permit flow tests of water supply connections.

7.11.3.2 Main drain test connections shall be so installed that the valve can be opened wide without causing water damage.

7.11.3.3 Main drain connections shall be sized in accordance with 7.11.2.

7.12* Fire Department Connections.

7.12.1 One or more fire department connections shall be provided for each zone of each Class I or Class III standpipe system.

7.12.1.1 The high zone fire department connection(s) shall not be required to be provided where 7.9.3 applies.

7.12.2 High-rise buildings shall have at least two remotely located fire department connections for each zone.

7.12.2.1 Asingle connection for each zone shall be permitted where acceptable to the fire department.

7.12.3 Fire department connection sizes shall be based on the standpipe system demand and shall include one 21⁄2 in. (65 mm) inlet per every 250 gpm (946 L/min).

7.12.3.1 An approved large diameter hose connection of a size to accommodate the required flow shall be permitted.