Australian Pipeline Valve - Installation, Operation and Maintenance Manual
26
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.
DIAGRAM 6
‘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
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
SEA
T RET
AINER
RING
SECONDAR
Y SEAL
CHANNEL
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
DIAGRAM 7
Two O-rings are utilised in the stem area for reliable performance, as
well as graphite fireseal.
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
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 8
