Regarding the calculation of flat cover and flat cover opening reinforcement, which one is more reasonable!
Thread Content
A jar with an inner diameter of 590mm, a flat cover for the head, a design pressure of 0.8MPa, a temperature of 220°C, a material of Q345R, and a medium of water vapor. The structure is shown in the figure below. Below are three algorithms from three colleagues. Let’s see which one is more reasonable! (Only φ89×3.6 can be used for the nozzle on the end plate) Colleague A: "The maximum sum of the diameters of the openings in the same cross section" is entered as 93mm, and the thickness of the flat cover δ1 is calculated ； After conducting the hole reinforcement calculations for the two hole nozzles respectively, calculate the thickness δ2 of the flat cover and take the larger value. Colleague B: "The maximum sum of the diameters of the openings in the same cross section is 188mm, and the thickness of the flat cover δ1 is calculated ； After conducting the hole reinforcement calculations for the two hole nozzles respectively, calculate the thickness δ2 of the flat cover and take the larger value. Colleague C: 1. Enter "the maximum sum of the diameters of openings in the same cross section" as 188mm, and calculate the thickness of the flat cover δ1 ； The opening reinforcement of the two-hole nozzle is not calculated, only the internal pressure of the nozzle is checked. ； 2. If "the maximum sum of the diameters of openings in the same cross section" is not entered, the thickness of the flat cover δ1 is calculated.' ； When performing the hole reinforcement calculations for the two hole nozzles respectively, the software prompts to thicken the flat cover to δ2' (δ2'>δ1'), and the flat cover thickness is δ2' ； 3. Compare the larger value of δ1 in method 1 and δ2' in method 2, and choose the larger one.
The size of the "end plate and barrel welding diagram" in the picture is 11, which should be 3mm. It is wrongly marked.
Is it okay to have 3 soldering legs? Should it be ≥ 6?
3mm higher than the cylinder, the total height of the weld is 11mm, 8+11>2 times the cylinder thickness 16
1 of C is correct. I just don’t know why the two holes have to be placed on the same center line. If they are not on the same line, the opening size will be the size of one hole, and the calculated thickness of the cover will be smaller.
In addition to what was mentioned before, the calculation of this case is quite interesting if you think about it carefully. The position of the two openings determines the calculation method. If the distance between the two holes is greater than 188, and the distance from the center of the opening to the edge is greater than 94, the flat cover only needs to calculate the opening reinforcement.
A: No theoretical or standard basis B: C1 is double calculated: is right. C2 is also right. You can take a look at ASME VIII-1 UG-39, which is very detailed.
I prefer colleague C. Sometimes the thickness of the flat cover is calculated to be different between C1 and C2, so I compare the value with C3 and then go to the larger value. Be conservative.
Colleague A, inputting a single hole is in accordance with GB/T150 6.3.1b