portable fire extinguisher, water type (gas cartridge)

 Principle and design

The extinguisher shall be upright type, thus operated by holding the extinguisher upright and piercing the gas cartridge by applying pressure on plunger or by pressing the squeeze grip thereby discharging the contents.

Capacity

The capacity of water type extinguisher should be filled to the specified level indicated in exterior
of the body shall be 9.0 ± 0.5 litre.

Shape

The shape of the body shall be cylindrical with an outside diameter of 175 ± 5 mm.

Construction

A cylindrical skirt having minimum 25 mm height shall be welded to the bottom dish.

Where carrying handle and/or supporting fittings are fitted to the body, these shall be either
welded or brazed. The carrying handle shall be made of mild steel or stainless steel rod not less
than 6 mm in diameter or fabricated out of mild steel or stainless steel sheets of same thickness
as the body and the clamp shall be of mild steel or stainless steel thickness of 3 mm, minimum.

The thickness of the shell shall be calculated in accordance with 7.2 but it shall not be less than 1.4 mm of the shell.

Syphon tube and Strainer

The syphon tube with strainer at free end shall be fitted inside the body. In case of squeeze grip
type, syphon tube shall be fitted in the cap.

Cap

To fix the cap to the neck the cap shall be screwed on the body up to a minimum of 16 mm effective length.
At
least 3 holes of not less than 2.5 mm diameter shall be drilled through the threaded portion of
the cap to form vents. The centres of the vent holes shall be 6.5 mm,

Nozzle

The nozzle of the extinguisher is such that it can complete the performance requirement
The hose (if provided) shall be of not less than 8 mm bore and length not less than 600 mm.

Expansion space

An air space shall be provided in the body above the specified liquid level which shall be of
sufficient volume to ensure that when the discharge nozzle is temporarily closed and the
extinguisher put into operation at a temperature of 27 ± 5 ºC, the internal pressure exerted shall not exceed 1.5 MN/m2.


Gas cartridge 

the maximum weight of the gas cartridge shall be of 60 gram

Test requirement

The extinguisher body and the cap assembly shall be tested to an internal hydraulic pressure of 3.0 MN/cm2 (30 kgf/cm2) for a period of 2 min. During the test it shall not show any sign of leakage.

In case of hydraulic burst test for the extinguisher, mechanical failure shall not occur at a pressure less than 4.5 MN/m2 (45 kgf/cm2).

When the extinguisher is set in operation under normal temperature conditions of 27 ± 5ºC with a stream starting in horizontal direction in wind-free condition, the water shall be expelled in the form of jet which shall maintain an effective throw of not less than 6 m for the minimum period of 60 s provided that at least 95 percent of water is discharged from the extinguisher within the maximum period of 120s.
For more information you can read IS 940 

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