Fire Bottles

Fire extinguishers are DOT rated cylinders filled with halon that protect the aircraft's Engine, APU, Lavatory and Cargo compartments and are manufactured individually or as a complete system to provide total fire protection. Systems are offered in a variety of configurations and range in size from 10 cu. in to 2500 cu. in. depending on application.

Types of Fire Bottles

Aside from the different OEMs, there are basically two types of fire bottles – o-ring and hermetic. The o-ring bottles, all the pressure is retained through the use of o-rings while the hermetic bottles seals the pressure through a welding process. The welding process is significantly more labor intensive than the o-ring process.

Blowdown Bottles

A blowdown bottle is a highly pressurized cylinder containing nitrogen which is used to force open doors or to bring down landing gear.

Standard Hydro Period for a Fire Bottle

This depends on the specific part number and the OEM. For some units it is five years and other units it is ten years. It is important to clarify some terminology – frequently we hear "my bottle is due for hydro". This means that the fire bottle must be hydro retested, which always includes an overhaul of the unit. Unlike an oxygen bottle, the fire bottle cannot only be hydrotested. This is part of the reason the price of a hydro for a fire bottle is more expensive than a hydro for an oxygen bottle.

The Purpose of an X-Ray

The x-ray is necessary to check for cracks and/or corrosion inside the cylinder. It is typically due in the 9th and 12th year from the DOM of the unit.

Standard Overhauls Do Not Include Cartridges ("Squibs")

SEMCO overhauls fire bottles per the latest CMM revisions. The cartridges are not part of the standard overhaul kit. Our policy is to include cartridges as extra costs to the customer if the time has expired (typically 12 years) or if the customer specifically requests cartridges on the repair or purchase order. The customer must explicitly request cartridges in order for SEMCO to provide them.