1-2-4-210

Aircraft fire-extinguishing use of 1-2-4-210

In fire-extinguishing applications, the 1-2-4-210 cylinder can be used as part of stationary aircraft fire protection equipment. It is associated with fire extinguisher assemblies such as the UBSH-4-4 type, where a spherical bottle is installed in the aircraft fire-extinguishing circuit and connected to the distribution system. On Mi-8, Mi-17, Mi-171E, and related helicopters, such assemblies may be used for fire protection of engine compartments, the main gearbox area, service fuel tank zones, and equipment compartments, depending on the aircraft version and installed fire protection layout.

1-2-4-210 cylinder in UBSH-type extinguisher assemblies

The 1-2-4-210 cylinder may form the pressure vessel base for unified spherical fire extinguishers. In this configuration, the bottle is filled and equipped only according to approved maintenance and overhaul documentation. The cylinder normally works together with shut-off and discharge components selected for the specific extinguisher assembly. For supply purposes, the cylinder itself is usually treated separately from the valve or pyrotechnic head equipment unless the order clearly specifies a complete extinguisher assembly. This distinction is important when comparing a bare cylinder, an overhauled bottle, and a fully assembled aircraft fire extinguisher.

Construction features of the 1-2-4-210 bottle

The 1-2-4-210 is described as a steel spherical aircraft bottle. The spherical body form is used where compact volume, pressure resistance, and predictable strength behavior are required. The cylinder is intended for high-pressure operation and is designed as a non-fragmenting type when used in the appropriate certified configuration. In some fire-extinguishing assemblies, the outside of the bottle may be protected by a reinforcing composite or fiberglass wrap. The exact external condition, coating, neck thread, and installed fittings must be checked against the physical item and its passport documentation before use or supply.

Stored media and system compatibility of 1-2-4-210

Depending on the aircraft system, the 1-2-4-210 cylinder may be used for compressed air, nitrogen, oxygen, refrigerant agents, or fire-extinguishing compounds. In fire protection systems, cylinders of this class are commonly associated with halon-type extinguishing agents and pressurizing gas, but the actual filling medium is determined by the aircraft manual and fire-extinguisher specification. The cylinder must not be identified only by external appearance. Correct application depends on the full designation, pressure rating, capacity, thread version, inspection status, and compatibility with the relevant valve, adapter, and system manifold.

Identification and procurement of 1-2-4-210

The marking 1-2-4-210 should be decoded and verified before ordering, repair, or hydrostatic inspection. The first digit indicates the spherical body type, the second identifies the neck-thread execution, the third indicates the bottle capacity group, and the final value identifies the working pressure class. For aircraft supply, it is important to specify whether the requirement is for an empty cylinder, a cylinder after inspection, a complete fire extinguisher assembly, or a unit with installed discharge fittings. Documentation, inspection status, production or overhaul history, and compatibility with the target aircraft should be confirmed before shipment.

Related system equipment: UBSH-1-4-4, PGKts, OR1-2.0-20-30. These positions are grouped by system function and installation context, not as interchangeable replacements.