Nilfisk 50mm Aluminium Flap Valve, For Industrial Ducted Systems.
Fits 60mm OD ducting, and springs shut when the hose is removed.
Second picture shows what a big industrial ducted can look like. But with a bit of imagination, they can be made out of almost anything.
The industrial flap-valves are used to suck up through industrial hoses, where bulk product, such as grain, iron ore, coal and pellets etc. accumulate regularly, same at conveyor discharge points
The original Nilfisk style 50mm and 38mm steel fittings from the Nilfisk GS83 and GM83 and the Nilfisk GB833 industrial vacuum cleaners etc are interchangeable in them.
At the moment, standard postage within Australia is capped at a maximum of $25! Maximise the saving on postage and buy some of the related parts below, or some dustbags and the filters or a new floor tool.
We at TVD carry out in-home repairs on built-in ducted vacuum systems in the Perth area from $135, call 08 9362 6044