Spirovent Air Eliminators

Spirovent Jr series air eliminators made by Spirotherm include horizontal and vertical models with a complete range of sizes in 1/2" through 1-1/2" with sweat or threaded piping connections. They effectively eliminate nearly 100% of air from the water and help to maximize efficiency of the heating system, while reducing maintenance and operating costs. Brass body construction, rated 150 psi at 270°F. Made in the USA.

How it works

Lower portion of the Spirovent air eliminator’s body consists of a main chamber with piping inlet/outlet, which contains the Spirotube coalescing medium. Here, the water flow slows down, allowing the microscopic air bubbles coalesce and become trapped by the Spirotube. In this low-turbulence area, the bubbles rise freely to the top of the eliminator, where the air vent is located.
Upper portion contains a specially designed float-type air vent. As air accumulates at the top of this chamber, it pushes down the water level and the float, which, in turn, opens the air valve until most of the air is vented. Then the process repeats again.

Bottom of the air eliminator has a 1/2" FNPT outlet, which is used for connection of the standard diaphragm type expansion tank. This outlet is also the best location for the fresh water feeder line, since the oxygen concentration in such water is highest and is easiest to eliminate when entering directly into the Spirovent.