CrisDom
Mechanical
- Apr 25, 2019
- 24
Dear All,
I've a doubt regarding the evaluation of the lowest stress ratio to be used to calculate Hydrotst Pressure for Heat Exchanger Shell Side.
I usually consider the main components for both Tube and Shell Side and I always consider exchanger tubes for both sides.
Actually I'm wondering whether it's correct to take into consideration tubes in evaluting the lowest stress ratio for calculating Shell Side Hydrotest.
I noticed that Compress does consider tubes to calculate Tube Side Hydrotest pressure, but is doesn't consider tubes to calculate Shell Side Hydrotest pressure.
In the past I managed a job based on GOST regulations and, in that case, applicable specifications highlighted that tubes shouldn't be considered in evaluating the stress ratio for Shell Side.
I suppose it depends ont he fact that the reaction to an external pressure is different from the one to an internal pressure, so it could be the reason why tubes could be excluded in calculating Shell Side hydrotest pressure.
This would imply that also for other equipment with different configurations a component subject to Ext pressure should be excluded when evaluating the Lowest Stress Ratio of the chamber that "contains" it: e.g. Should a shell under a jacket be considered to calculate the hydrotest pressure of the jacket?
I tried to find a Code Interpretation, but I didn't succeed, so I'd like to know whether an official position has been expressed or if it's simply a logical and not contestable assumption.
Thanks for your feedback.
Have a great day!
Regards
Cristiana
I've a doubt regarding the evaluation of the lowest stress ratio to be used to calculate Hydrotst Pressure for Heat Exchanger Shell Side.
I usually consider the main components for both Tube and Shell Side and I always consider exchanger tubes for both sides.
Actually I'm wondering whether it's correct to take into consideration tubes in evaluting the lowest stress ratio for calculating Shell Side Hydrotest.
I noticed that Compress does consider tubes to calculate Tube Side Hydrotest pressure, but is doesn't consider tubes to calculate Shell Side Hydrotest pressure.
In the past I managed a job based on GOST regulations and, in that case, applicable specifications highlighted that tubes shouldn't be considered in evaluating the stress ratio for Shell Side.
I suppose it depends ont he fact that the reaction to an external pressure is different from the one to an internal pressure, so it could be the reason why tubes could be excluded in calculating Shell Side hydrotest pressure.
This would imply that also for other equipment with different configurations a component subject to Ext pressure should be excluded when evaluating the Lowest Stress Ratio of the chamber that "contains" it: e.g. Should a shell under a jacket be considered to calculate the hydrotest pressure of the jacket?
I tried to find a Code Interpretation, but I didn't succeed, so I'd like to know whether an official position has been expressed or if it's simply a logical and not contestable assumption.
Thanks for your feedback.
Have a great day!
Regards
Cristiana