The client’s facility has multiple fume cupboards sharing one large extract ductwork system, and their consultant was looking for safe discharge via a chemically resistant stack.
The size and scale of the stack was such that there were only a limited number of UK plastics specialists with sufficient factory space to manufacture, and the client was also looking for full design, including calculations, which reduced the list still further.
The stack was to be located on a secondary roof, against the wall to the roof above, and needed to discharge at a sufficient height to meet environmental regulations and resist challenges caused by prevailing winds and adverse weather.
In total the stack was 10.5m tall, with a 45 degree 1250mm ø flanged inlet, false bottom and drain, and the discharge tapering to 950mm ø.
Roperhurst’s team fabricated the stack sectionally using a combination of fabric-back polypropylene, steel support rings and layers of chop glass strand mat reinforced with a general purpose resin.