ANSI/API Standard 662 is the national adoption of ISO 15547:2000 - Petroleum and Natural Gas Industries-Plate Heat Exchangers. ANSI/API Standard 662 gives requirements and recommendations for the mechanical design, materials selection, fabrication, inspection, testing, and preparation for shipment of plate heat exchangers, sometimes referred to as plate-and-frame heat exchangers, for use in petroleum and natural gas industries.This standard covers gasketed, semi-welded and welded plate heat exchangers constrained within a frame.As used in this standard, the term heat exchangers, or exchangers, includes coolers, heaters, condensers, evaporators and reboilers.