Regarding the issue of the lug pad covering the longitudinal seam
Thread Content
I ran into this problem today as well. In the small cylinder, either the lifting lugs or the connections inevitably have a longitudinal seam. It was decided to cover the longitudinal seams with lug shims, and the covered portions of the longitudinal seams were smoothed out. Currently, the intersections of the welds around the shims with the longitudinal seams are not welded (it is true that the equipment requirements are not high). The question is: why is a pneumatic pressure test requirement specified for the welds of the lifting lug shims in the standards, whereas this requirement does not apply to the lug seat shims? What is the difference between a lifting lug pad and an ear seat pad?
I believe it is necessary to ensure the reliability and integrity of the welds on the lug pad plates under short-term loads; therefore, airtightness is required (similar to the requirements for reinforcement rings). As for the welds on the ear seat pads, emphasis is placed on weld strength, and it is essential to maintain the appropriate weld leg height and surface quality. Personally, I think the standards set for the welds on the lug gusset plates are too strict; it is sufficient as long as the cross-sectional area of the weld root is adequate and there are no defects on the weld surface that exceed the specified limits. Once a standard is chosen, it must be followed. It is recommended not to use standard lugs; instead, design your own lugs to avoid the constraints of standards.
Since it’s a small cylinder, the overall weight of the equipment is likely not very high either; one can simply design lifting lugs by oneself
Ultrasonic testing, radiographic inspection, and magnetic particle inspection all need to be included; that’s what happened to me last time. Heat treatment also needs to be added