API STD 667 pdf download Plate-and-Frame Heat Exchangers Scope This standard gives requirements and recommendations for the mechanical design，materials selection,fabrication，inspection,testing， and preparation for shipment of plate-and-frame heat exchangers for use inpetroleum, petrochemical, and natural gas industries. lt is applicable to gasketed and semi-welded plate-and-frame heat exchangers. This document does not cover the requirements for fully welded plate-and-frame , fully welded...