Armex II manages the expansion and contraction of heating and cooling system water, and providing automatic water make-up. It also offers dissolved gas deaeration within the same self-contained system.

Armstrong offers a smaller, safer vessel, with a tank design that 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 operates at atmospheric pressure, and 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 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 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.