Masoneilan 33000 Series Triple Offset Butterfly Valve

Overview

The Masoneilan 33000 Series is a triple offset butterfly valve from Baker Hughes Masoneilan, designed for the applications where a conventional resilient-seated or double offset butterfly valve reaches its limits: extreme pressure and temperature, cryogenic LNG, fire-safe service and tight bi-directional shut-off. It is a metal-to-metal sealing design that Baker Hughes positions for both control and isolation duty in a lightweight body, and it is the manufacturer’s answer for lines that need a butterfly valve’s compact dimensions without accepting the leakage of an elastomer seat.

In Oman and the GCC, Seven Star LLC proudly supplies the Masoneilan 33000 to LNG, refining, petrochemical and power generation projects across the Sultanate of Oman and the wider GCC. Our instrumentation division in Muscat supports body style, material, actuator and accessory selection, and every order is backed by genuine Baker Hughes documentation and warranty.

Triple Offset Operating Principle

In the Masoneilan 33000 the sealing geometry is offset in three ways: the shaft sits behind the seat plane, it is offset from the pipe centreline, and the sealing surfaces are conical so that the axis of the cone is also angled. Taken together, these offsets mean that the disc does not rub against the seat at any point during rotation. It travels clear of the seat and makes contact only as it reaches the closed position, which Baker Hughes describes as zero breakaway torque and a globe-like seating action. With no rubbing, there is no friction wear on the seal, so shut-off performance stays consistent through repeated cycles and the actuator torque requirement stays lower.

The circular conical sealing technology also matters for capacity. Baker Hughes notes that many competing designs use elliptical seals, which create more drag, reduce Cv and increase wear; the circular cone is intended to deliver maximum Cv with a better seal. The Masoneilan 33000 is bi-directional, with the preferred flow direction having the shaft upstream, and the inherent flow characteristic is equal percentage with a Cv ratio of 50:1.

Engineering Design of the Masoneilan 33000

The Masoneilan 33000 uses a cast body with an integral bonnet and short neck, available as lugged (drilled-through or drilled-and-threaded), wafer, double flanged short pattern or double flanged long pattern bodies. Face-to-face dimensions follow API 609 category B for sizes up to 48 inch, and flange facings are raised face as standard with ring type joint and butt weld ends optional. Body materials are carbon steel WCC, stainless steel CF8M and low-temperature carbon steel LCC, with duplex and chrome-moly available on request.

Two design details distinguish the valve in service. First, a square drive shaft runs the full length of the drive chain, so there are no pins or keyways to weaken the shaft or shear in high-velocity or vibrating service, and the disc is self-centering in the seat without a shaft expansion gap. The square drive also lets the actuator or manual operator be rotated to any 90-degree position on site. Second, in the Masoneilan 33000 the seat ring is field replaceable and the disc is a two-piece design, so components can be inspected, removed and replaced without taking the whole valve out of the line.

Key Features

The following capabilities are drawn from the Baker Hughes fact sheet and technical specification for the Masoneilan 33000 Series:

• A patented triple offset design with a metal-to-metal seat gives zero bi-directional leakage with minimal friction during throttling.
• Circular conical sealing improves the seal and preserves capacity compared with elliptical seal designs, delivering full-capacity Cv.
• A square drive shaft removes pins and keyways, allows actuator orientation in 90-degree steps and lowers the operating torque requirement.
• An extended bonnet option supports LNG cryogenic conditions down to minus 196 degrees Celsius.
• Fire-safe construction is documented to API 607 and ISO EN 10497, and the page lists API 598 zero leakage in the preferred flow direction.
• The technical specification lists ISO 15848 fugitive-emission qualification for the low-emission package; the applicable class and test gas are confirmed at quotation.
• Field-replaceable seat rings and a two-piece disc keep maintenance downtime short.
• Actuation options include spring-diaphragm Model 31, 32 and 33 actuators, scotch yoke piston actuators and a gear-type manual operator.

Industrial Applications

Baker Hughes lists LNG, cryogenic LNG, refining, petrochemicals and power generation as the industries for the Masoneilan 33000, with isolation, cryogenic service, distillation, hydroprocessing, reforming, cracking, blending, quenching and fractioning, charge gas compression and separation as typical applications. That scope matches the Sultanate’s energy infrastructure: LNG liquefaction and export facilities, refinery and petrochemical units in Sohar and Duqm, and gas-fired power and water plants where large-diameter lines call for compact, lightweight valves with tight shut-off.

In Oman and the GCC, Seven Star LLC supplies the Masoneilan 33000 together with the parts and instruments that complete the package. Maintenance planners can order the Masoneilan 33000 Series seal kit from the same source, engineers comparing butterfly options can review the Masoneilan 39005 high-performance butterfly valve, and throttling applications can be fitted with a Masoneilan SVI3 digital valve positioner for precise control.

Technical Specifications

The table below summarises the published data for the Masoneilan 33000 as given in the Baker Hughes technical specification (Rev. D) and fact sheet. Please refer to the full documents for materials of construction, dimensions, weights and actuator data.

Related Masoneilan spares and rotary valves include the Masoneilan 33000 Series seal kit, Masoneilan 36005 V-Max ball valve, Masoneilan 31000 Series PFA-lined rotary valve and Masoneilan Camflex II 35002 rotary control valve.

Request a Quote for Masoneilan 33000

Seven Star LLC invites engineers, EPC contractors and plant maintenance teams across Oman and the GCC to submit a formal request for quotation for the Masoneilan 33000. Please send the line size, ASME class, body style, process fluid and temperature, required seat leakage class and the actuator or manual operator preference, and our team will confirm the configuration, advise on regional availability and provide the Baker Hughes technical specification for download from this page. In Oman and the GCC, Seven Star LLC delivers genuine products with manufacturer documentation, warranty coverage and responsive local support.