Hi aslam
Whatever khalid & myself try to explain is a practical area of concern when we use spring specially in large bore pipe.
You might not have encounter the problem but it's a real one ( My personal opinion).
If you ask me to answer whether I have ever made data sheet for nozzle load for WNC case I say "NO"
Still I feel as professional stress engineer it's my duty to cover all stress relater area & ensure safety even if I do not reflect it on black & white paper.
I like some expert to enter in this topic & give proper guidance.
Regards
Habib