Safety valve outlet pipe
Thread Content
The outlet of the safety valve is connected directly to the atmosphere; I’m not sure how the design institutes where you work determine the operating and design parameters for the pipeline downstream of such a valve. After selection, is it planned for the pressure pipeline according to the design pressure? ；
Pipes that are directly connected to the atmosphere and designed for normal pressure are not considered pressure pipes.
Although I am not familiar with the relevant specifications, I personally believe that the pipeline grade should be designed taking into account the discharge pressure downstream of the valve. If the pipeline behind the safety valve discharges directly into the atmosphere, it is not a pressure pipeline because it is at atmospheric pressure. If it is discharged into a system with a pressure of 0.1 MPa or higher, it is considered a pressure pipeline.
The end of the pipeline is indeed at atmospheric pressure, but the flange grade at the outlet of the safety valve is high – how can this be explained? Moreover, I use it in medium and high-pressure pipelines; without a specified design pressure, I feel uneasy, and if a pressure is specified, it’s usually quite high, so it definitely has to be used in pressure pipelines
In pipeline tables, you always specify the design temperature and pressure; based on these values, the material is generally classified as a pressure pipeline. This question is interesting
I think generally it should be based on the design pressure
Using safety as the criterion, discharge into the atmosphere behind the safety valve is not considered a pressure pipeline
So, how do you determine the design pressure?
For example: This is for one of our projects; operating pressure: ATM/0.3, design pressure: ATM/0.6
Is the unit MPa? Is it still a pressure pipeline?
Calculate the back pressure behind the valve according to HG/T20570, and then determine the design pressure based on that value.