Seeking answers regarding equipment material issues
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Our company currently has a tower made of Q245R material, which has been unused for 2 years. Now, a new project requires a distillation tower and we would like to reuse that existing tower. The design parameters for the tower made of Q245R are as follows: pressure of 0.35–0.1 MPa, temperature of 200°C. For the distillation tower needed in the new project, the recommended material is Q345R, with a working pressure of -0.05–-0.095 MPa and an operating temperature of 200–280°C. May I ask the experts whether it is possible to use the Q245R tower as a substitute?
It’s possible, provided that the strength calculation passes. Judging from the parameters, the calculation should be fine; of course, the medium also plays a certain role
Yes, it’s possible; however, the new project involves negative pressure, so a negative pressure check is required. It is estimated that an external reinforcing ring needs to be installed. As well as the possibility that opening reinforcement may fail in cases of negative pressure. But it should all be solvable.
I guess it’s possible; check with negative pressure
From the perspective of the material’s allowable stress, it is permissible. It’s just that the existing tower needs to undergo a comprehensive inspection, especially regarding its wall thickness. Then conduct a strength check. Positive and negative pressure fluctuation operation? Is the design temperature for the new project around 300°? ? ?
Was it really not noticed that the designed negative pressure was -0.1? What really needs to be verified is that the allowable stress of the material varies significantly at different temperatures
Thank you for helping to clarify this. The new tower operates under negative pressure, while the old tower has only been stored for 2 years without being used; in fact, it’s brand new and has never been used at all, not even installed yet. The operating temperature of the new tower is between 200 and 300 degrees. Could you help check whether the old tower can withstand temperatures above 200 degrees?
There should be no problem, as long as it is legal and compliant, the medium isn’t too special, and its strength is satisfactory
Using Q245R is the same as using Q345R; their elastic moduli are similar, and the thickness of the tower resulting from the design is the same. Considering cost, Q245R is a more suitable choice. The condition you provided is a pressure vessel under external pressure; the main task is to conduct stability checks, and if those checks pass, then there’s no problem. Of course, such equipment also needs to get the approval of a special inspection agency, right? I’m not sure; please guide me, experts. .