Armstrong’s Astro 2 three-speed circulators provide unmatched performance over a wide range of head and flow requirements. With three speed settings to choose from, Astro 2 circulators allow for output adjustment in the field. This operating flexibility and range of pumping performance means 16 models of Astro 2 circulators can be used to replace more than 160 competing circulator models. Astro 2 bronze- and stainless-steel circulators are in compliance with lead-free regulations, including California Health and Safety Code Section 116875. The removable check valve allows a reduction in installed costs by eliminating multiple system check valves.