New Armex II Expansion System Launched by Armstrong


Armstrong has launched a new generation of expansion system which builds on the success of its Armex range. In addition to managing expansion and contraction of heating and cooling system water, and providing automatic water make-up, the new Armex II also offers dissolved gas deaeration within the same self-contained system.

New Armex II Expansion System Launched by Armstrong

Armex II (Image: Armstrong)

The Armex II Series of high volume pressurisation and degassing systems has major advantages for sealed heating and chilled water applications. One key benefit is that system requirements can be met with a much smaller, safer vessel.

The space-saving advantages arise from the Armex II tank design, which accepts a greater volume for fluid expansion in comparison to traditional tanks. Incorporating a specially-designed receptacle instead of a fixed air-cushion vessel, Armex II has acceptance levels approaching 90%. It also has the advantage of operating at atmospheric pressure. As no pressure is exerted on the external vessel wall, the system is far safer and exempts the product from the statutory health and safety regimes, and resulting costs of maintenance, necessary where pressurised vessels are in use. It also means that hydronic system components can be of a lower pressure rating.

The Armex II’s transfer/control pumping package manages the movement of water between the sealed heating or chilled water system and the Armex II receptacle, introducing make-up water automatically as required. As the package is microprocessor controlled, it can be used for a wide range of temperatures, pressures, transfer volumes and variations in code regulations and installation practices. System monitoring and diagnostics are available with a BMS interface or remote communication module.

The Armex II controller also manages the deaeration feature of the system. Water expands from the pressurised heating or cooling circuit into the sealed rubber membrane in the vessel where it is stored at atmospheric pressure as liquid. Dissolved gases come out of solution and are allowed to leave the vessel via the air release valve. The Armex II controller is programmed to pass adjustable volumes of water out of the pressurised heating/cooling circuit into the vessel on a timed basis. In this way the system is kept continually deaerated.

The effectively gas-free operation made possible by the Armex II has numerous benefits over alternate solutions. There is no need for time-consuming bleeding of air from decentralized vent points. Full thermal output is maintained. The need for mechanical air separators is eliminated, and pumps are protected against air and cavitation. Heat transfer is also improved as bubbles do not form on the hot boiler heating surfaces, and the system offers quieter operation for building occupants.

The Armex II Series of high volume pressurisation and degassing systems is available with expansion vessels between 200 and 5,000 litres in volume. For greater expansion requirements, multiple receptacles are integrated together and managed from a single control unit.

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