Although not yet accepted officially by the American pressure vessels and piping design and construction codes, which continue to require that stress relief of welds be done by heating, the stress relief by vibration has gained considerable popularity over the last several years.

The scope of this article is to make a description of the vibration method, the theoretical principles upon which it is based, its operational procedures and the present “state of the art”.

The article is complemented by an experimental section. Three pieces of pipe were welded, one of which was left “as welded”, the second was stress relieved by heating and the third one was stress relieved by vibration. Several coupons were cut off the pipes, to be submitted to tensile, impact, hardness tests and metallurgical analysis.