Can an elbow be welded directly to the cylinder?
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This post was last edited by liaifeng on 2018-8-21 at 16:58. Today I saw a diagram drawn by a colleague (as shown below), and I asked if it’s possible to weld in this way directly A colleague asked in return, is there a standard that prohibits it? I’m at a loss for words{:2_34:} I want to ask whether an elbow can be welded directly to the cylinder Are there any standards or guidelines that contain similar provisions or explanations?
It is recommended to add a spool, otherwise it’s difficult to accurately calculate the reinforcement required for making holes. Although welding is possible, the straight sections of elbows are usually short, which makes them difficult to work with and hinders the application of insulation materials. The flow of fluid at the elbow has to change direction by a large angle, resulting in increased wear; replacement becomes troublesome once the elbow is damaged. Unless there are specific requirements, it is better not to do this
Agree with you: handshake
Common sense does not require standards to govern it. What was said on the first floor is completely correct.
After direct welding, the stresses at the elbow and those at the areas reinforced by openings affect each other; in other words, the stress conditions are complex (this can be clearly seen through a stress analysis). If the equipment pressure is low and the pipeline stress is minimal, this approach is not a problem; however, when there is high pressure, along with corrosion or fatigue, it has a significant impact on the equipment’s lifespan. Although there are no standard regulations prohibiting this, it is still necessary to give more consideration to the stress factors and the situation mentioned on the second floor.
You’re welcome, let’s discuss together :)
Let’s check the pressure rating and the medium involved I’ve seen cases where the elbow extends in by half, resulting in low pressure resistance.
It is recommended to draw an enlarged view of this area in proportion.
Calculating the reinforcement through openings and the stress analysis is difficult, especially for pressure vessels; for vessels operating at atmospheric pressure, this approach might be acceptable.