Browse categories of Deaerators for medium-large systems Brass deaerators Steel deaerators Accessories for deaerators The deaerator separates and removes the air circulating within the closed circuits of medium-large heating and cooling systems. Brass deaerators DISCAL®, Deaerator. Steel deaerators DISCAL®, Deaerator. Flanged connections. Accessories for deaerators Insulation for deaerators DISCAL® 551 series.