Australian Pipeline Valve - Installation, Operation and Maintenance Manual 25 SIDE ENTRY 2P TRUNNION BALL VALVES API6D STANDARD - FS9000 SERIES Automatic Relief of the Cavity Independent floating spring loaded seats are always in contact with the ball to provide an effective tight seal even at low differential pressures. Independent upstream and downstream seat permit draining of fluid from the body cavity, allowing double block and bleed operation. With the standard ‘single sealing’ feature, when the valve is closed there is an automatic body cavity release of over pressure to the line through the downstream (or upstream) seat. The pre-tightened seat springs are preset to automatically relieve excess cavity pressure caused by thermal expansion back downstream (or upstream). Once pressure exceeds the API6D (6.8) maximum (1.33 times the valve maximum pressure rating at 38°C at the time of publishing this IOM). Also refer section 10.0 for more information. ‘Double sealing’ feature (available on request), maintains the sealing capacity of the valve even in the case of failure of the upstream seat. Body cavity over pressure in this case can be released through a relief valve to atmosphere or flare, or can be recycled back upstream. A combination of double sealing features on the downstream side and single sealing on the upstream seat is available on request. This configuration maintains the sealing capacity of the valve in case of failure of the upstream seat and release of the body cavity over pressure through the upstream seat. Full Bore or Reduced Bore Full bore and reduced bore are available in all sizes. Full bore is full through conduit bore size to API6D to facilitate pigging. Sealant Injection System When the seat and/or stem sealing system is damaged, the grease injection valve can inject sealant into the valve for temporary sealing. Under normal circumstances Australian Pipeline Valve valves require no lubrication. Stem Sealing System Two O-rings are utilised in the stem area for reliable performance, as well as graphite fireseal. Flexible Operation The seat and stem bearing has a Teflon coating which is low friction and self-lubricates to reduce the valve operation torque. Operators The valve may be operated by hand, pneumatic operator, motor, hydro- pneumatic operator and hydraulic operator, etc. NACE The full range of APV valves can meet NACE standard MR-01-75, latest edition if necessary. DIAGRAM 6 DIAGRAM 7 SEALANT INJECTION FITTINGS END HEIGHT OF THE DIFFERENTIAL AREA SEAT O-RINGS BALL SEALANT GROOVE D2 SEAT INSERT SAFETY CAP CHECK VALVE BODY-END O-RING SEAT SPRING HOLDING SCREWS SEAT RETAINER RING SECONDARY SEAL CHANNEL STEM BACK-UP RINGS BACK-UP RINGS O-RINGS BODY BALL STEM PLASTIC PACKING INJECTION FITTING UPPER TRUNNION TRUNNION TO BODY SEALS UPPER TRUNNION BEARING STEM BEARING WASHER DIAGRAM 8