API 6D Ball Valve Guide
API 6D ball-valve inquiries normally define pipeline-service requirements around bore, body construction, pressure class, materials, seat arrangement, cavity-pressure behavior, testing and operator or actuator configuration.
Trunnion, floating, top-entry and fully welded constructions solve different installation and maintenance problems even when they share the same nominal size and pressure class.
A useful API 6D RFQ should identify the required seat/isolation philosophy, end connection, design conditions, materials, fire-safe or emissions requirements, testing, actuation and project documentation.