Failure analysis of galvanized iron pipeline accessories of a fire protection system

In the present work, the failure of galvanized iron pipes accessories has been analyzed. These accessories are part of a fire protection system in an industrial building. It has been observed the confluence of several circumstances, as defects in the design or in the execution of the installation, false alarms with filling of the pipe installation, geometry of the accessories made in malleable white-heart cast iron and inherent superficial defects of this type of accessories, that have lead to the sudden failure of an elevated number of such accessories during one of the fillings of the installation. An exhaustive macro and micrographic analysis has been done, in order to identify the combined fracture micro-mechanisms observed for this material.