This document defines the requirements for weld fittings and machine weldments using an orbiting welding head suitable for use on cold worked 3AL-2.5V titanium, 21Cr-6Ni-9Mn CRES, and 718 nickel alloy tubing. Fitting standards covered by this specification include non-separable welded elbow, tee, and reducer fittings, and reconnectable 24-degree cone fittings, such as sleeves and unions.
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.