Problem : Tank lifting as per appendix J
Problem : Tank lifting as per appendix J
(OP)
I refer to Par. J.3.8.3 of API650
The required safety factor of 4 is referred to Tensile strength or Yield Strength of material.
Why I must double the load acting on a lug ?
If a customer require 1.5 or 1.25 I may assume this value or I must assume 2 ?
Many thanks in advance
The required safety factor of 4 is referred to Tensile strength or Yield Strength of material.
Why I must double the load acting on a lug ?
If a customer require 1.5 or 1.25 I may assume this value or I must assume 2 ?
Many thanks in advance





RE: Problem : Tank lifting as per appendix J
So, a safety factor of 4 doesn't really agree with any of the three codes listed above. I would consult someone who is very familiar with the requirements before making a decision. Lifting attachments are a critical part of the design and should not be taken lightly. Lifting lugs are typically designed very conservatively since safety is paramount and steel is cheap.
I am not sure why the code requires that the load be doubled for design purposes. My only idea is that this is meant to be an impact factor. However, I have never seen a code impose an impact factor. This is usually a client requirement.
If your client is requiring a 1.25 or a 1.5 impact factor, you must also ensure that you meet code requirements. If the code says 2.0, then you must use 2.0 for an impact factor. The client requirements are in addition to the code requirements. However, if they are both impact factors, then only meet the most stringent requirement.