I think you will get an insight into the wrong and right approach by reading COADE Mechanical Engineering News - May 1993 pages 32 to 34. This can be accessed via Support / Newsletters options on this website.

Happy Reading.
_________________________
Dave Arthur
Lead Stress Engineer
Wood Group Engineering (North Sea) Ltd.
Tel: +44 (0)1224 851226
e-mail: dave.arthur@woodgroup.com