Types of automatic fire sprinkler heads

According to Australian Standard AS2118, there are an array of automatic fire sprinkler head types that are used for a wide variety of applications.
Russ Porteous
CEO, Firewize
06 Jan, 2021

Automatic fire sprinkler systems are installed in buildings to control the growth and spread of fire. There are an array of automatic fire sprinkler heads designed and installed for specific applications.

Australian Standard AS2118 provides a list of automatic fire sprinkler head types (see below) that may be used;

Conventional sprinkler
A sprinkler designed to produce a spherical type of discharge with a proportion of water being thrown upwards to the ceiling. A conventional sprinkler is usually designed with a universal type deflector enabling the sprinkler to be used in either the upright or pendent position. Some conventional sprinklers are, however, made in two types: one suitable for use in the upright position and the other for use in the pendent position.
Spray sprinkler
A sprinkler designed to produce a parabolic discharge below the plane of the deflector with little or no water being discharged upwards to wet the ceiling. A spray sprinkler is made in two types: one suitable for use in the upright position and the other for use in the pendent position.
Flush sprinkler
A sprinkler designed for use with concealed piping where it is required, for reasons of appearance, to make the sprinklers inconspicuous. A flush sprinkler is installed pendent, with the base flush to the ceiling, but has an exposed heat responsive element and retracted deflectors which drop down to the normal position on actuation. Flush sprinklers are normally used in hotel lobbies, dining rooms, offices, boardrooms and parts of retail stores. Flush sprinklers are not suitable for use in atmospheres that are corrosive or subject to a high dust content. Flush sprinklers utilizing chains to locate the deflector are only suitable for use with level ceilings unless specifically listed otherwise.
Recessed sprinkler
A sprinkler comprising a spray sprinkler provided with a separate escutcheon housing, usually two-piece adjustable, where part of the sprinkler yoke and heat responsive element are mounted within the recessed housing. NOTE: Escutcheon housings are used with the spray sprinkler to ensure that the response time of the heat responsive element is not unduly impeded and that the discharge spray pattern is not obstructed.
Concealed sprinkler
A sprinkler comprising a spray sprinkler that is fully recessed in a concealed housing and fitted with a cover plate assembly designed to release at or before the operating temperature of the sprinkler. Concealed sprinklers provide the same unobtrusive appearance as flush sprinklers.
Sidewall sprinkler
A sprinkler designed for installation along the walls of a room close to the ceiling. A sidewall sprinkler provides a one-sided (half-paraboloid) discharge pattern directed outwards with a small proportion discharging on the wall behind the sprinkler. Sidewall pattern sprinklers are not normally a substitute for conventional or spray pattern sprinklers and their use is limited to such locations as offices, entrance halls, lobbies and corridors
A sidewall sprinkler may be used with advantage in drying tunnels and hoods over papermaking machines where condensate dripping from sprinklers and pipework at the ceiling could be troublesome and also in certain other locations such as shop windows and under platforms having low headroom where sprinklers would be subject to damage.
Dry pendent and dry sidewall sprinkler
A sprinkler designed for use in portions of premises protected by a dry or an alternate wet and dry system where it is not practicable to install sprinklers in the upright position, or on a wet system where the sprinklers may be subject to frost. Dry pendent and dry sidewall sprinklers are designed having either conventional or pendent spray type deflectors. Dry pendent and dry sidewall sprinklers are manufactured integral with drop pipes of varying lengths, the valve being so placed that there is no pocket or depression where water can be trapped.
Dry upright sprinkler
A sprinkler essentially the same as the dry pendent types except that an upright type deflector is incorporated. A dry upright sprinkler is designed for use in wet systems for the protection of concealed spaces subject to freezing
Fast response sprinkler
A sprinkler that has a high level of thermal sensitivity which enables it to respond at an early stage of fire development. See Australian Standard AS 4118.1.1 for the thermal characteristics of fast response sprinklers.