API STD 660 pdf download.Shell–and–Tube Heat Exchangers for General Refinery Services 1.1 SCOPE 1.1.1 This standard defines the minimum requirements for the mechanical design, material selection, fabrication, inspec- tion, testing, and preparation for shipment of shell-and-tube heat exchangers for general refinery services. 1.1.2 As used in this standard, the term heat exchangers includes heaters, condensers, coolers, and reboilers. 1.2 GENERAL...