We assemble supports like LEGO building blocks - say, large bore piping saddle support, add axial stops, add guide lugs - support design complete. All these are individually load rated standard support items.

But, if we consider the overall load/stiffness rating of the large bore piping restraint +Y,X,Z - considering secondary structure too, the overall design can fall short of requirement.

Given the volume of such support design activity, we knowingly dilute this activity, which can give way to piping integrity failure at times!

We need to find some way to tackle this problem in non nucler applications, as in nuclear plants, we have tackled this support design very effectively.

reg,
sam

In the above post what I wanted to express that, we do not perform piping stress analysis in comprehensive manner in non nuclear area, knowingly!

It is just like confident surgeon does not use Dr Atul Gawande checklist just because he tries to ensure safety to patients, not selfish people in health industry who perform multiple surgery on one issue just for money!

If we have concern for safety, we need to use nuclear foolproof practices in non nuclear areas too!

reg,
sam

In my experience, there's no such thing as a "standard" support in plants and refineries. As competitors (and clients) have decided that the old methodologies are adequate, it's difficult to convince others that calculating linearized stiffness values for all support locations that partially or completely fall outside of the structural department's scope is worth the expenditure.

Well, this has been issue in my department too when the company decided to emerge power and chemical plant engineers together.
Because of stubborn department head, we have to use 30~40 years old std support drawings which haven't even calculated the structural integrity because it's cheaper than subcontracting support vendor.
Since we cannot check stuructural integrity ourselves, we send the details and support load to structural department to check.

I will most probably hanged now but on a normal plant a good pipe designer needs only some paper and pen. Theoretical calculations what "computer generation" is doing with 8 decimal accuracy are nothing more than rubbish. I just reviewed some design calc where calculated fatigue cycles is 4921.971. That is in the issued report. Calculation is based on formula and factors that are not more than thump sucks.

If company is using 30 year old designs and they have worked they will work in the future. I see a lot of basic mistakes in overall designs - Code compliant but badly wrong. Please get basics right first.

Some 40 years back my lecturer on design told a story from his early working life. He was tasked to design a new street light pole. He spent days doing the calculations and sent the report to his manager. Some time later he was drinking his morning coffee and saw a lamp post with snow on top. Suddenly a bird landed on the snow. He realized that he had not considered the bird in his calculations. What was the lesson in this story? Please think hard.