Steel duct dimensions??

[ondablade]

Does anybody happen to know how the nominal diameter of spiral wound steel air ducting (e.g. 160mm) relates to the actual diameter? Is it for example the internal diameter?

It'd make some sense if this was the case, as the same male slip in joining sleeves would then fit regardless of the gauge of the steel the duct is made from.

I need to buy some ducting and blast gates, and am wondering if i can possibly use the nice moulded ones Ed Morgano at Clear Vue in the US does - these have 6.29 inch (159.76mm) internal diameter female sleeves/sockets each side.

Ditto on the usual spiral wire reinforced smooth bore clear PU/PVC flexible hose. Does the size refer to the internal diameter, and does it matter all that much anyway given that it's probably capable of being persuaded (?) over an inch or so of a duct stub with the help of some hot water..

ian

 

[JonnyD]

With the spiral ducting i have the bends and tee sections etc fit inside the ducting so i assume the straights are made to the nominal dimensions and the bends etc reduced slightly to fit inside.

I dont know about the flexible stuff but 100mm and 150mm flexible piping slips over 100 and 150mm metal spiral ducting so i would assume the 100mm is the internal dimensions.

cheers

Jon

 

[ondablade]

Ta Jon. That seems spot on. I called a local maker this morning, they say they make their male joining sleeves for 160mm ducting to 157mm or a little larger - it fits inside the spiral duct....

ian