Regarding the layout of a discharge pipe
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While reviewing the piping diagram of a certain project, I noticed that one of the pipelines that lead from the tank top to the flare system without going through a safety valve (operating intermittently) connects at a 90-degree angle directly to the flare main of the facility. I checked some standards, and they all state that if the pipeline after the safety valve leads to the flare main, it should be connected at a 45-degree angle from above. So can this discharge pipe, which is connected directly without a safety valve, be connected at a 90-degree angle? I have limited experience with piping; I hope those who know more can offer some guidance. Thank you all!
It shouldn’t be possible. . . . . . . .
It is estimated that gas is emitted here under normal pressure, and the amount of emission is small; even if it is introduced into the flare at 90 degrees, the increased resistance this creates inside the flare can be disregarded.
I agree with what was said above – inserting at a 45-degree angle is also done to reduce pressure loss. Since your system operates intermittently, the pressure loss is minimal; it’s possible to insert it directly into the main pipe from above without any problems~
May I ask what the diameter of this pipeline is, according to the poster? Generally, this can also be done for large sizes. The key is whether the back pressure is acceptable?
The torch main is 200, and this pipeline is 150. The back pressure should be acceptable; there is no safety valve, and the pressure is not high.
The flare branch pipes in our plant are connected in this way: the discharge branch pipes connect to the flare main pipe at a 45-degree angle, in line with the flow direction of the fluid. But personally, I don’t think this way of connecting things is absolute; what you said seems to be correct as well.
For branch pipes with a diameter of DN50 or larger, there are clear regulatory requirements for making diagonal joints in the flow direction; however, for those with a diameter less than 50, this requirement need not be followed, as the impact is minimal and it’s fine to proceed without it.