Habonim Catalog Interactive 2024 V04 15022024 - Catalog - Page 26
VALVE FEATURES
Seat Configurations
Standard Seat
A flexible, precision-machined seat that provides the highest seal capabilities (EN12567
Rate A) in high pressure and vacuum conditions. Its unique design reduces valve torque,
facilitating a more compact, lower-weight automated package. The design also reduces
wear, thus extending the life of the seat. The seat perimeter has pressure-equalizing slots
to allow pressure to penetrate into the body cavity for better sealing and for avoiding upstream
seat collapse into the valve cavity while turning the valve ball from the open to closed position
under high differential pressure.
Standard seat
Self-Relieving-Seat (SRS)
The Self Relieving Seat (SRS) is used mainly in syltherm and dowtherm services in the chemical
and biopharm industries. Both syltherm and dowtherm have a high thermal expansion coefficient
and in trapped cavities (such as when the valve ball is in its closed position) even a moderate
temperature increase will cause dramatic pressure build-up that can cause cessation of valve
operation, seat swelling, and even valve shell failure. The SRS is designed to flex and allow the
trapped pressure to escape into the pipeline, while shutting off as soon as the peak pressure is
relieved. The pressure relief is achieved by a special internal groove that is machined into the seat
radii facing the ball. Additional radial grooves enable the pressure to bypass the ball and access
the internal groove. The seat sealing surface is in the central internal section and provides tight
shutoff. The outer section of the seat above the internal groove gives the support needed to the
ball when higher line pressure pushes the ball toward the downstream seat, thus preventing
“crushing" of the seat. SRS seats can be used with a differential pressure up to ASME Class #300.
Self-Relieving-Seat (SRS)
Seat-seal
In some use cases valve must seal the pressure at the upstream side, which contradicts the
traditional floating ball mode of operation (where sealing is typically done on the downstream
seat only). Habonim’s solid one-piece seat-seal design blocks the flow through the back
of the seat, generating an upstream seal. Seat-seal can be used with differential pressure up
to ASME Class300. For higher differential pressures use either a valve with hybrid seats, or a dual
floating ball valve integrated into a one block or trunnion mounted valve.
Seat-seal
Hybrid Seat
When a soft seated floating ball valve is held even momentarily at mid position, the upstream
seat is only partially supported by the ball and can be pushed towards the valve cavity by the
force of the stream. This deformation is amplified with increased media density, high differential
pressure and/or high velocity. Under these extreme conditions the deformation can: cause the
ball to grip the unsupported area of the soft seat and jam the valve; slice the seat by the port
edge of the ball; or trigger stem twisting (caused by excessive torque applied by the operator
trying to close the valve). Habonim’s line of Hybrid seats were developed especially to overcome
the problems posed by high differential pressure applications. The combination of a metallic
housing and polymer insert offers the stiffness of a metal seat with the bubble tight shutoff
leakage rate and operating torque of a soft seat. Different hybrid seat designs were developed
to meet the needs of different applications, and are designated by the metallic housing design.
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VALVES
Hybrid seat
