duct support

[henerythe8th]

Currently analyzing an HVAC duct system in a nuclear facility (nuke waste) and curious if there is a standard method of determining the type/strength of supports.

Also, do typical HVAC supports restrain motion in the three orhtographic directions or do they restrain the moments about these axes as well?
Before you think that I am a fool, I realize that you want to allow movement in particular directions to allow for thermal expansion, etc. In this circumstance we have a temperature rise of about 200degF...

 

[ChasBean1]

Standard HVAC ventilation ductwork is guided by SMACNA. Usually this entails sheet metal straps or threaded rod trapeze hangers. Local seismic requirements might have sway brace requirements, etc. Don't look to local building codes and standards to define needs for this application. NRC (Nuclear Regulatory Commission), CFR, or a military standard might define these requirements.

 

[lilliput1]

Provide ductwork with adequate length on the hanger rods so expansion will not cause more than 15 degrees deflection of the rods from vertical. Provide bends to allow ductwork flexibility for expansion. Ductwork is not designed to resist moments. It is simply supported and diagonally braced where required to resist lateral motion from seismic, wind, forces or thrust.