The image shows flange for rectangular ducting complete with sealant
The price is for 5 metre length
Duct Flange for rectangular ducting – 5 metre lengths @ £5.78 per metre (Minimum 10 lengths)
Side flange corners D20/3S 75mm length @ £33.75 per box 250pcs
Side flange corners D20/3L 95mm length @ £45.50 per box 250pcs
G/Clamps @ £26.25 per box 100pcs
Joining Rectangular Ductwork
The widths available are typically 20mm, 30mm, and 40mm, and the size used depends on the size of the duct itself. Ductwork manufacturers follow a document known as DW/144 which is supplied by the HVCA (Heating & Ventilating Contractors’ Association). This document provides the industry standard specification for the correct frame widths as well as much more information pertaining to ductwork manufacture and installation. The correct frame widths are also governed by other factors such as system pressure and the use of ‘stiffeners’. It can get a little complicated, but as a general rule 20mm flange is fine for ducts no bigger than 1m in size in the longest dimension; 30mm can be used for ducts from 1m up to 2m, and 40mm is used for ducts above that. For example, a duct of 800mm x 800mm can use 20mm flange, but 1100mm x 200mm will need 30mm flange. The sheet metal flange is cut to length and then assembled with corner pieces. These corner pieces have pre-punched holes on them which provide the means to bolt the duct together. Frames are often referred to as ‘Mezframes. The duct pieces can then be bolted together using either 8mm or 10mm bolts depending on the flange size used. G clamps can also be fitted where the flanges are bolted togetherfor extra stability. G clamps are generally supplied by the manufacturer of the duct flange profiles, and can be purchased on our website. Mez frames only bolt together on the corners so you can understand that on larger ducts extra clamps will be required.