What's the correct way to set a manual balancing damper quadrant so it doesn't rattle?

Slide the regulator handle quadrant over the square damper shaft. Tighten the central locking wing-nut or hex bolt firmly down against the flat spot of the shaft. Try to shake the handle with your hand; if there is any play, slap a backup locking washer on it. Loose dampers will vibrate at high frequencies under system air pressure, creating building-wide acoustic noise issues.

['Slide the regulator handle quadrant over the square damper shaft. Tighten the central locking wing-nut or hex bolt firmly down against the flat spot of the shaft. Try to shake the handle with your hand; if there is any play, slap a backup locking washer on it. Loose dampers will vibrate at high frequencies under system air pressure, creating building-wide acoustic noise issues.']

Stop if

• Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.

Steps

• Stop and verify the approved detail, manufacturer instructions, foreman direction, and project specs before touching it.
• Slide the regulator handle quadrant over the square damper shaft. Tighten the central locking wing-nut or hex bolt firmly down against the flat spot of the shaft. Try to shake the...

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