SAE ARP4698A

This SAE Aerospace Recommended Practice (ARP) is intended as a guide for choosing a minimum wall thickness of tubing, based only on pressure, for use with welded tube fitting ends that have a “tube wall code” covering a range of tube wall thicknesses. These wall thicknesses are based on burst pressure with an arbitrary additional safety factor. If the weld fitting user has already established the required minimum wall thickness for given performance conditions, this guide does not apply.