Design Conditions for Stress Analysis
Design Conditions for Stress Analysis
(OP)
Hello,
I am having confusion with respect to temperatures which I need to select for a pipe stress analysis. Do I have to consider the Minimum Design Temperature (zero DegC) for stress analysis or is it enough to take only installation temperature (21degC).
My temperatures conditions are
T1: 84 DegC (max design temp)
T2: 0 DegC (minimum Design temp)
T3: 52 DegC (operating temp)
or the below conditions are ok?
T1: 84 DegC (max design temp)
T2: 21 DegC (Installation temp)
T3: 52 DegC (operating temp)
When I change temperature T2 from 0 to 21 Deg, expansion case stress ratio reduces drastically (from 92% to 7%).
My opinion is that minimum design temperature is for selecting the material so that it doesn't experience the brittle fracture. And upto 21 DegC there is no thermal expansion so we do not need to consider the 0 (zero) DegC for stress analysis.
Thank You
I am having confusion with respect to temperatures which I need to select for a pipe stress analysis. Do I have to consider the Minimum Design Temperature (zero DegC) for stress analysis or is it enough to take only installation temperature (21degC).
My temperatures conditions are
T1: 84 DegC (max design temp)
T2: 0 DegC (minimum Design temp)
T3: 52 DegC (operating temp)
or the below conditions are ok?
T1: 84 DegC (max design temp)
T2: 21 DegC (Installation temp)
T3: 52 DegC (operating temp)
When I change temperature T2 from 0 to 21 Deg, expansion case stress ratio reduces drastically (from 92% to 7%).
My opinion is that minimum design temperature is for selecting the material so that it doesn't experience the brittle fracture. And upto 21 DegC there is no thermal expansion so we do not need to consider the 0 (zero) DegC for stress analysis.
Thank You





RE: Design Conditions for Stress Analysis
RE: Design Conditions for Stress Analysis
RE: Design Conditions for Stress Analysis
- Design Temperature if a fictitious number and should only be used for pipe wall calculations.
- The Maximum/Minimum Operating Temperature is a real temperature and is the proper factor to use for Thermal expansion/contraction calculations for Piping systems.
If you use the Design Temperature then you are 'over designing' the system resulting in added cost.
Sometimes its possible to do all the right things and still get bad results
RE: Design Conditions for Stress Analysis