Do you know the types of elbows used in rectangular duct?
Harry Thompson IVAugust 31st, 2018
Sign as seen hanging at Sig Cox (founded 1926), Sheet Metal Contractor in Augusta, GA
The determination of the types of elbows used in a duct job depends on a variety of factors, including the engineer's preference, the contractor's influence, and space allowances.
Radius elbows take up more space than Square Back Elbows with Turning Vanes as shown in duct design.
In the case of the NOLA new airport project, the engineer preferred radius fittings due to abundant space. However, there is one square-backed elbow visible. Can you spot it?
2" Hollow Vane and 2" PROrail installed to turn air in Square Backed Elbows. Often used when there are space constraints as they take up less space than Radius Elbows.
2" Vane and Rail installed in Square Back Elbow.
Turning vanes are installed to redirect airflow in square elbow fittings.
Radius elbow with Square Throat.
Radius Elbows with Radius Throat (reinforced with Tie Rods).
Radius Elbow with tight throat radius.
Elbows made with Buttonlock instead of Pittsburgh often appear in better condition since they avoid the tinner’s hammer used with the Pittsburgh Lock.
