Sprinkler positioning in angled & irregular-shaped rooms

Sprinkler Positioning in Angled & Irregular-Shaped Rooms

Sprinkler Positioning in Angled & Irregular-Shaped Rooms

According to NFPA 13, For standard & extended coverage pendant & upright spray sprinklers, where walls are angled or irregular, the maximum horizontal distance between a sprinkler and any point of floor area protected by that sprinkler shall not exceed 0.75 times the allowable distance permitted between sprinklers, provided that the maximum perpendicular distance is not exceeded.

Spacing of standard spray pendant and upright sprinklers:

NFPA 13 classifies the occupancies according to hazard degree, therefor the sprinkler spacing shall be different form hazard degree to another one, below we will clarify the sprinkler spacing according to hazard degree

For light hazard occupancy:

• Maximum distance between sprinklers is 4.6m
• Minimum distance between sprinklers is 1.8m
• Maximum distance from sprinklers to walls is 2.3m
• Minimum distance from sprinklers to walls is 100mm

For ordinary hazard occupancy:

• Maximum distance between sprinklers is 4.6m
• Minimum distance between sprinklers is 1.8m
• Maximum distance from sprinklers to walls is 2.3m
• Minimum distance from sprinklers to walls is 100mm.

For extra hazard occupancy:

• Maximum distance between sprinklers is 3.7m (for density ≥ 0.25gpm/ft2) or 4.6m (for water density <0.25 gpm/ft2)
• Minimum distance between sprinklers is 1.8m
• Maximum distance from sprinklers to walls is 1.85m or 2.3m according to density
• Minimum distance from sprinklers to walls is 100mm

Examples for standard spray sprinklers distribution in angled rooms:

The following figures include examples for distribution of standard pendant and upright sprinklers in different hazard occupancies:

Sprinkler Positioning in Light Hazard Angled Room

Sprinkler Positioning in Ordinary Hazard Angled Room

Sprinkler Positioning in Extra Hazard Angled Room

Spacing of extended coverage pendant and upright sprinklers:

The rule of angled or irregular shaped rooms can also be applied to extended coverage sprinklers, so the distance of an extended coverage sprinkler and a point in a floor area is permitted to be 0.75 of the maximum allowable distance between sprinklers provided that the perpendicular distance to the wall doesn't exceed half of the maximum allowable distance between two sprinklers.

Maximum protection area per sprinkler and maximum spacing between sprinklers for extended coverage sprinklers shall be as the following table.

Extended Coverage Sprinklers Spacing & Protection Area

References of this article:

• NFPA 13 - 2019 edition (Standard for the Installation of Sprinkler Systems)

Read also:

• SPRINKLER CHARACTERISTICS ACCORDING TO NFPA 13
• SPRINKLERS IN ELECTRICAL ROOMS ACCORDING TO NFPA 13
• FIRE DEPARTMENT CONNECTION ACCORDING TO NFPA 13
• SEISMIC SEPARATION ASSEMBLY
• RETURN BEND REQUIREMENTS ACCORDING TO NFPA 13
• DISTANCE BELOW CEILING FOR STANDARD PENDANT & UPRIGHT SPRINKLERS
• SPRINKLER DISTRIBUTION IN SMALL ROOMS - NFPA 13

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