Source: https://www.flameshieldproducts.co.uk/flameshield-fireduct/product-standards/bs-476
Timestamp: 2020-01-20 15:38:55
Document Index: 559321743

Matched Legal Cases: ['art 24', 'art 24', 'art 24', 'art 24', 'arts 1', 'art 24']

Flameshield Fireduct, Fire Rated Ductwork, BS 476 Part 24
Product Standards - Flameshield Fireduct is Fully Compliant with BS 476 Part 24
Flameshield Products have been fully tested in accordance with BS 476 Part 24: 1987 (ISO 6944: 1985) for up to 2 hours stability, integrity and 2 hours insulation for Type A ducts (fire outside) and 4 hours stability, integrity and 2 hours insulation for Type B ducts (fire inside). The standard for assessment involves a variety of different scenarios to ensure the ductwork meets all current requirements. Flameshield Fireduct also meets the smoke extract criteria of up to 4 hours integrity.
Flameshield Fireduct, exceeds all the minimum requirements for fire resistance in ductwork, making it the first choice to stay compliant.
The test duct details are much the same for both of these standards (BS 476 Part 24 and EN 1366 Parts 1 & 8) however the requirements set down within the two standards are different in many ways.
It is a requirement to test two different scenarios, duct A (fire exposure from outside to inside) and duct B (fire exposure from inside to outside). A BS 476 Part 24 test is required for both duct A and duct B standards, insulated and un-insulated and rectangular in shape, all installed horizontally. Under the requirements specified within this test standard other orientations can be assessed. For example:
- The test standard enables ducts sized up to 1250x1000 (rectangular), or 1000 diameter (circular) to be incorporated as part of a tested solution. Ducts sized over these maximum tested solutions can be assessed.
Following a successful duct B test the cross sectional area of the duct can be measured to determine the ‘loss of shape’ after being exposed to the furnace gasses. The standard requires the duct to maintain at least 75% of its original shape.