This International Standard is not applicable to valves for pressure ratings exceeding PN 420 (Class 2500). Annex A of this International Standard provides guidelines to assist the purchaser with valve type selection and specification of requirements when ordering valves.
Annex B of this International Standard provides a checklist summary of information to be provided by the manufacturer and/or purchaser when ordering valves. Informative Annex F is included giving requirements of the API Monogram Program for equipment covered in the specification.
Normative Annex G includes technical enhancements to the base ISO document. This edition of API Spec 6DSS is the modified national adoption of ISO 14723, Petroleum and natural gas industries- Pipeline transportation systems-Subsea pipeline valves.