whereas a 1-pole unit always keeps one leg energized (hot)

Featuring a 5-3/16" full runner diameter

Designed with a single pole double throw (SPDT) configuration

this specific orifice is calibrated for natural gas applications

Siemens Building Technology 331-2973 Kit 320720-756 whereas a 1-pole unit alwaysThe Siemens 331 2973 is a rugged, metal fabricated No. 4 pneumatic damper actuator designed for the gradual or positive control of HVAC systems and fire smoke dampers. Built for high demand applications, this piston type actuator features a 4 inch stroke and a nominal 8 13 psi spring range, ensuring precise positioning of ventilating systems and mixing boxes. This universal kit includes a mounting plate, pivot post, clevis, and damper crank,