Difference between welded tees and extruded tees in CAESAR II
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This post was last edited by LJD_22 on 2018-5-23 08:47. In the modeling and calculation processes using CAESAR II, for ordinary projects, tees are generally made by extrusion, corresponding to the 6-Extruded type; whereas for media with stringent requirements such as LNG, tees are usually fabricated by welding, That is, 3- welding. From the perspective of relevant specifications, these two tees do not differ much in appearance, but their stress enhancement factors vary significantly. I checked some relevant information, and many people say that tees made by extrusion have a higher pressure resistance, while welded tees are relatively weaker in this regard. However, during the calculations it is often found that when 6-Extruded is used, the stress values do not meet the requirements; whereas when 3-welding is chosen, the stress levels are sufficient and are significantly lower than the specified values. So I’m a bit confused – is it true that welded tees are more durable than those formed by extrusion? I was wondering if there are anyone who knows a lot about these two types of tees and could explain it to me? :lol
This post was last edited by Pigsty in the Wheat Field on 2018-6-13 at 14:32. You have confused two different concepts: the welding mentioned in C2 refers to fully formed tees, while ordinary welded tees are those made by welding sheet metal together – these are not the same thing. For specific details, refer to Appendix E of GB50316
In the pipeline manual for the power industry, the SIF values for elbows and tees are to be filled in manually up to C2; the types listed in the software can be ignored, hehe
Hello, I entered Si based on the stress increase factor for tees specified in the power GD manual. When choosing 3 – integrally formed tee, the secondary stress is quite different from that when choosing 6 – thermocompressed tee; the secondary stresses are 50% and 80% respectively. What’s going on?
Since the stress increase coefficient is different, the stress will naturally be different as well
The stress increase coefficient should be set to the same value; choosing 3 for fully formed tees results in a secondary stress that is twice that of choosing 6 for extruded tees.
Take screenshots of the interface you entered and the calculation results
310 points corresponds to the three-way junction point; the stress increase factor is the same as that for input 2. When choosing between a 3-welding tee and a 6-extruded welding tee, there is a significant difference in secondary stress, with a difference of one fold.
This post was last edited by FMSD on 2019-4-16 14:03. Are you a beginner? For units 300-310, the stress at node 310 is the same; however, the stresses at the other two nodes 310 are different because you did not set the same SIF values. Remember: a tee consists of three units, and each unit requires its own SIF to be set.