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9 THEATRES AND MUSIC HALLS (PROTECTION ON THE STAGE SIDE OF THE PROSCENIUM WALL)

9 THEATRES AND MUSIC HALLS (PROTECTION ON THE STAGE SIDE OF THE PROSCENIUM WALL)

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AS 2118.1—1999

76

Dry pendent sprinklers shall be installed in air-circulating system plenums formed by one or
more false ceilings within the cold chamber.
NOTE: Where practicable, sprinkler piping should be located in normal temperature conditions
above the cold chamber with dry pendent sprinklers connected thereto penetrating into the cold
chamber.

Air circulation fans shall be closed down automatically on operation of the sprinkler
system.
Sprinklers shall not be installed where there is likelihood of mechanical damage due to
movement of goods within the cold store.
5.10.2 Piping within the cold chamber
The following special conditions shall apply where it is necessary to install the piping
within the cold chamber, or where it is desired to house the sprinkler piping within a single
small cold chamber:

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(a)

The sprinkler installation in the cool room shall be of the permanent dry type and the
maximum number of sprinklers controlled by one dry valve shall not exceed 50.
These groups of 50 sprinklers may be installed as tail-end dry systems on the basis of
at least one control assembly (wet, dry or alternate wet and dry, as circumstances
dictate) for each five groups.
Each tail-end system shall be controlled by a subsidiary stop valve (see Clause 8.2.4)
and shall include either a water flow alarm switch or an electric alarm pressure switch
(see Clause 8.10.5) to indicate the particular section that is operating. These sectional
warning systems are additional to the water motor alarm on the main control
assembly. Where there is a series of tail-end systems and one main control assembly
operating on the dry or alternate wet and dry principle, care needs to be taken to
ensure that the air/gas pressure on the tail-end system is maintained at not less than
the air pressure in the system between the control assembly and the tail-end dry
valves.
Differential dry valves used in tail-end systems connected to an installation operating
on the dry or alternate wet and dry principle shall be suitably modified to retain air
pressure in the system piping between the main control assembly and the underside of
the tail-end dry valves.

(b)

Sprinklers installed in an air circulation plenum formed by a false ceiling within the
cold chamber may be disregarded when determining the maximum number of
sprinklers required under Item (a) above if the sprinklers are fed from the piping
feeding the sprinklers in the cold chamber.

(c)

The air supply for charging the sprinkler system shall be taken from the cold chamber
from the freezers of lowest temperature or through a chemical dehydrator.
Compressed nitrogen gas in cylinders may be used as a substitute for air; however,
care shall be taken to provide a pressure-reducing valve to reduce the gas pressure to
not more than 800 kPa to avoid over-pressurizing the system piping.
NOTE: In these circumstances it is desirable to include a pressure-relief valve set to operate
at 900 kPa.

(d)

Piping joints shall be of a high standard of gas-tightness.

(e)

The system shall be provided with a low air/gas pressure alarm.

(f)

Dry pipe valves shall be housed outside the cold chamber in areas where the
temperature is maintained above 4°C. Where valves are normally provided with a
liquid seal, because of the problem of evaporation and possible ice formation in the
piping, the sealing medium shall be a fluid such as propylene glycol.

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77

(g)

AS 2118.1—1999

All piping downstream of the dry valve shall be installed above ground such that it
can be readily dismantled and reinstated to permit thorough purging of moisture after
operation.
Pipe jointing and hangers shall permit easy removal of the piping and an inspection
point shall be provided at the position of entry into the cold chamber. Changes of
direction shall be made by using tees with one branch sealed off instead of elbows.
Pipes shall be sloped to drain (see Clause 7.5).

(h)

Notwithstanding the requirements of Clause 2.3.2.4, sprinklers may be installed in
either the upright or the pendent position, having regard to the necessity for the
sprinkler system to be dismantled for drying out after each operation.

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© Standards Australia

AS 2118.1—1999

S E CT I ON

78

6

S P RI NKLE RS , S P RAYE RS
MULT I P LE CONT ROLS

AND

6.1 GENERAL
Sprinklers shall not be altered in any respect nor have any type of ornamentation or
coatings applied after leaving the production factory except as permitted by Clauses 5.6.15
and 6.8.
6.2 TYPES OF SPRINKLERS, SPRAYERS AND MULTIPLE CONTROLS
6.2.1 Standard sprinklers
Sprinklers shall comply with the requirements of AS 4118.1.1. Systems designed in
accordance with Sections 9, 10 and 11, shall use standard sprinklers. Sprinklers other than
standard sprinklers are included in Clause 6.2.2, Special sprinklers.

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Standard sprinklers consist of the following (see Clause 1.6.24):
(a)

Conventional sprinklers.

(b)

Spray sprinklers .

(c)

Flush sprinklers.

(d)

Recessed sprinklers.

(e)

Concealed sprinklers.

(f)

Sidewall sprinklers .

(g)

Dry pendent and dry sidewall sprinklers .

(h)

Dry upright sprinklers .

6.2.2 Special sprinklers
Special sprinklers are listed sprinklers other than those types in Table 1.1 of AS 4118.1.1.
Systems incorporating special sprinklers shall be designed in accordance with the relevant
parts of Clause 2.3.3.
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Special sprinklers consist of the following (see Clause 1.6.17):
(a)

Extended coverage sprinkler (EC).

(b)

Large drop sprinkler (LD).

(c)

Early suppression fast response sprinklers (ESFR).

(d)

Residential sprinkler (RES).

(e)

Extra large orifice sprinkler (ELO).

(f)

Enlarged orifice sprinkler (EO).

6.2.3 Sprayers
Sprayers in an installation shall be medium or high velocity type. They are special purpose
sprayers for use in water spray systems which may or may not form part of sprinkler
systems intended for the extinguishment or control of fires involving flammable liquids and
for the cooling of storage tanks, process plant and exposed structural steel work against heat
from an exposure fire.
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Sprayers consist of the following (see Clause 1.6.19):
(a)

Medium velocity sprayers.

(b)

High velocity sprayers.

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AS 2118.1—1999

C6.2.3 Sprayers have directional discharge characteristics to provide direct
impingement on to the protected surface and are available with cone angles ranging
from 40° to 180°. A solid discharge cone is produced from the sprayer by either internal
swirl vanes, tangential velocity swirl, or single orifice and deflector, with the minimum
spray discharge pressures ranging from 150 kPa to 350 kPa, thus providing the higher
water discharge velocities.
6.2.4 Multiple controls
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Multiple controls shall be selected in accordance with their listing (see Clause 1.6.12).
C6.2.4 Multiple controls are used in systems with medium velocity or high velocity
sprayers of the ‘open’ type in circumstances where it is required to operate small groups
of sprayers simultaneously. They are also used in connection with bypass piping for
alarm purposes. The controls are made in various sizes relevant to the diameter of the
valve and the number of sprayers that are to be fed therefrom. The sizes range from
20 mm to 80 mm.

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6.3 STANDARD SPRINKLER K FACTORS, ORIFICE AND THREAD SIZES
Sprinklers shall conform to AS 4118.1.1.
Nominal K factors for standard sprinklers are as follows:
(a)

10 mm orifice 5.7 ±5%.

(b)

15 mm orifice 8.0 ±5%.

(c)

20 mm orifice 11.5 ±5%.

6.4 APPLICATION OF SPRINKLER TYPES
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The types of sprinkler for the appropriate hazard class shall be limited to those nominated
in Clauses 9.4.1, 10.4.1.1 and 11.4.1.1 except as permitted in Clauses 9.4.5, 10.4.1.2 and
11.4.1.3.
6.5 TEMPERATURE RATINGS
The temperature ratings chosen shall be not less than 30°C above the highest anticipated
temperature conditions except under the following circumstances :
(a)

Under glazing, translucent plastics and uninsulated metal roofs, in unventilated
concealed spaces and show windows on external walls, and in other locations that are
directly exposed to the sun, it may be necessary to install sprinklers with a
temperature rating between 79°C and 100°C.

(b)

In High Hazard systems protecting high piled storage, sprinklers having a nominal
temperature rating of 141°C shall be used at the roof or ceiling roof or ceiling, except
where in the case of special sprinklers, the listing, manufacturers published data
sheets and codes and standards referenced herein, recommend an alternative
temperature rating.

(c)

Where high temperature sprinklers are installed within drying ovens or hoods over
papermaking machines and the like (see Clauses 5.6.14 and 5.7.6), sprinklers at the
ceiling or roof immediately over and to a distance of 3 m beyond the boundary of
such structures shall be of the same temperature rating, subject to a maximum of
141°C.
NOTES:
1 Sprinklers are listed in nominal temperature ratings ranging from 57°C to 260°C.
2 For normal conditions in temperate climates, ratings of 68°C to 74°C will be generally
suitable.

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