Constructed with dual bellows

Common causes include carbon buildup

SMOKE2-S) without field-splicing

This Emerson Alco 030620 Valve is a 2-way normally closed solenoid valve designed for demanding industrial fluid control

Siemens Building Technology 331-2973 Kit 320720-756 Constructed with dual bellowsThe 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,