A P P E N D I X 3 DESIGN FEATURES APV Trunnion Mounted Ball Valve Construction Features Function Up-stream Sealing Two-way Valve The up-stream seal of the valve is effected by the advanced spring pre-tightening seats which automatically adjust. The two-way valve has two seats that can be sealed in both directions, so there’s no limitations of flow direction during installation. As line pressure increases the seat reacts to the force of the pressure to form an effective seal. In the absence of line pressure, coil springs around the seat unit provide a tight seal by keeping the seat in contact with the ball. Double Block & Bleed Valve Being “up-stream side sealing”, the valve can bleed out the trapped fluid in the body cavity when the valve’s in fully open or fully closed position. The fluid is intercepted by seats on up-stream and down-stream side. Bleeding the dirty fluid periodically can reduce damage of the sealing surface and prolong the service life of the valve. Once the integrity of the cavity is ensured, the upper stem seal may be replaced under working pressure. However, this depends on the size and class as designs vary. Also prime the stem sealant nipple with emergency sealant before attempting to replace the upper seal. Australian Pipeline Valve - Installation, Operation and Maintenance Manual 24 SIDE ENTRY 2P TRUNNION BALL VALVES API6D STANDARD - FS9000 SERIES Specification Standards General design standard API6D Pressure-temperature rating ASME B16.34 Face to face dimensions ASME B16.10 Flange type and dimensions ASTM B16.5 Butt-weld ends ASME B16.25 Inspection and test API6D/API598/ISO14313 Manufacturing Specifications Down stream Up stream DIAGRAM 4 Down stream Up stream DIAGRAM 5 DIAGRAM 3