Norton 8300 Series
Multi-Size Unitrol Door Closers
Multi-size power: The closer spring assembly can be adjusted through a wide power range
Two Power Ranges: Adjusted through a range of sizes, 2 through 6
Non-handed
Aluminum alloy shell: Closer bodies are constructed of a special aluminum alloy
Adjustable backcheck cushioning
Adjustable delayed action closing
Non-critical Valves
Molded slim style cover
Unitrol arm (parrallel arm only), please specify door width
Adjustable
sweep speed: An independent regulating valve, hex-keyed-operated,
permits adjustment of the general closing speed.
Latch
speed: An independent regulating valve, hex-key-operated, permits
adjustment of the door's speed for approximately the last 5 degrees of
the closing cycle.
Unitrol arms combine the features of a double lever arm overhead door
stop/holder with the backcheck feature of the door closer to reduce
door stopping shock loads to a minimum. The Unitrol uses a compression
spring buffer at the soffit plate/arm shoe that will absorb 30 lbf. of
force, 5° prior to the door’s dead stop. Coupled with the door closer’s
backcheck feature, this arm provides the most controlled stop available
with a surface door closer.
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