The PDF of ASME B16.34 is 206 pages and API SPEC 6D is 80 pages. API SPEC 6D is coordinated with ISO 14313; and references ASME B16.34 for rating tables and material groups, radiographic ultrasonic testing.
API SPEC 6D valves include gates, balls, plugs and checks for pipeline, petroleum and natural gas systems. Many generic details are illustrated, full bore openings and end dimensions defined. Painting, marking, storage and documentation requirements are identified.
Both standards reflect some testing techniques. ASME B16.34 permits wafer bodies (not allowed? in SPEC 6D?). ASME B16.34 includes extensive pressure temperature rating tables for material groups in a manner similar to B16.5.