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DD420S Threshold Seal

DD-420S Threshold Seal

Mann McGowan DD-420S, is a robust threshold seal providing acoustic, cold smoke and environmental sealing when used in conjunction with suitable doors.

DD-420S has achieved a 30 minute fire rating when tested to BS 476 pt. 22 1987.
Acoustic values of upto 34dB can be achieved depending on door type selected.

  • High quality aluminium threshold seal
  • Seals gaps up to 13mm
  • Simple to fit with slide and click mechanism
  • Easy to adjust using slot head screwdriver
  • 30 minute fire rating
  • Excellent noise-reducing performance up to 34dB
  • Available in 3 standard lengths 630, 930 and 1130mm
  • Optional end plates and cover plates


Technical Information

Full fixing instructions supplied with the product.

Please contact our Technical Team if you require additional advice.


DD-420S has been assessed to BS 476 Part 22 for use on FD30 Door sets.

DD-420S has been successfully tested to BS EN 1634-3 for cold smoke sealing (air leakage).

Cycling test: 200,000 opening and closing cycles.

Acoustic performance test

Acoustic tests have been conducted in accordance with the standards listed below:

BS-EN 10140-1
BS-EN 10140-2

34dB can be achieved.


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