About flange temperature and pressure
Thread Content
This post was last written by allen_zhang on 2018-7-13 09:17 The editor has a question to ask all friends. I am currently designing a pipeline with a design pressure of 1.8Mpag, a design temperature of 80°C, and a medium of C4. The current A105 flange is 150 pounds. Is it necessary to upgrade to CL300?
The temperature and pressure are enough. You can use 150. What are the considerations when increasing it to 300?
The explanation given to me by the review is that the standard flange temperature and pressure does not take into account the impact of the external load of the pipeline on the flange, so there must be some margin. My review of the design conditions concluded that there is no margin, so it needs to be upgraded to CL300.
It is recommended to go to the process first to verify the design temperature and pressure. If the conditions provided by the process have enough margin, there is no need to upgrade the pipeline. After all, the prices involved in CL300 and CL150 are not the same.
You are welcome to discuss the content you see on the WeChat official account
I've heard what you said in the review, but I'm not a materials professional, so I can't judge. Maybe it's really necessary or maybe it's too conservative.
You are right in your review. When the temperature and pressure are so tight, if it is a public engineering medium, find a way to select the design pressure to see if the value is too large, so that you do not need to upgrade the scale. If it is a toxic, flammable, corrosive medium, upgrade the scale to avoid the harm caused by flange leakage. According to the medium you mentioned, it is recommended to upgrade the scale. Thanks!
It's completely unnecessary, as long as the temperature and pressure levels are not exceeded.
I have also seen this. I personally think that the grade of the flange refers to its own pressure resistance. The impact of external loads is a matter of layout that the stress professional must consider. Even if there is leakage, it is not due to the strength of the flange itself.
This classmate, if this is the case, can you ask, how much temperature and pressure margin do you usually leave for this kind of flammable medium without upgrading the scale, or can you provide a detailed analysis of the specific situation?
You are from a refinery, right? At 80°C, it is 18.3MPa, which is indeed no margin. It's okay to consider safety, and the ones I've come across are generally based on pipeline grade. In this case, the pipeline grade must also be 300.