Masoneilan 33000 Series Triple Offset Butterfly Valve Seal Kit
Overview
The Masoneilan 33000 Series triple offset butterfly valve delivers bubble-tight, zero-leakage shutoff without the metal-to-metal wear of a conventional butterfly disc, by combining a triple-offset shaft geometry with a conical sealing surface that only makes contact in the final degrees of closure. Because the seat and shaft each carry a different sealing duty – the laminated soft seat provides the primary bubble-tight closure while the packing gland around the shaft prevents atmospheric leakage during the valve’s rotational stroke – a Masoneilan 33000 Series rebuild kit has to address both systems together, and Baker Hughes specifies different gasket materials by pressure class (NR40 nickel-reinforced graphite as standard, SST100 tanged stainless steel reinforced graphite at CL600) as well as an entirely different metal-to-metal seat and extended bonnet arrangement for cryogenic service. None of this is captured under a single stocked part number; each kit is engineered against the confirmed size, pressure class, and standard or cryogenic configuration of the installed valve.
Backed by genuine manufacturer documentation, Seven Star LLC proudly supplies this Masoneilan 33000 Series triple offset butterfly valve seal kit to LNG terminals, refineries, and isolation valve applications across Oman and the wider GCC. Seven Star LLC’s instrumentation division confirms the pressure class, seat material (soft seat or cryogenic metal seat), and gasket type against the customer’s nameplate before every order, ensuring the seat, gland packing, and gasket all arrive matched to the actual installed valve.
Operating Principle
The Masoneilan 33000 Series achieves zero-leakage shutoff through triple-offset geometry – the disc’s seating axis, shaft centerline, and bore centerline are each offset from one another – so that the disc sweeps clear of the seat through most of its travel and only engages in a cam-like final closing motion, virtually eliminating the rubbing contact that wears a conventional concentric butterfly disc and seat. Standard service uses a laminated soft-seat material with conical sealing technology that Baker Hughes states performs at full rated Cv for longer than elliptical seal design, while cryogenic service shifts to a metal-to-metal seat with an optional extended bonnet, moving the shaft packing gland further from the cryogenic process fluid so it operates at a more moderate temperature than the flow path itself.
Around the shaft, standard Masoneilan 33000 Series valves use passivated or braided graphite gland packing, while cryogenic variants use a similar passivated or braided graphite configuration but supported by the extended bonnet geometry described above; in both cases the packing gland components include stainless steel flanges, nuts, and studs that must be re-torqued evenly on reassembly to avoid uneven shaft loading. The body/bonnet gasket varies specifically by pressure class and service: NR40 nickel-reinforced graphite sheet as standard, SST100 tanged stainless steel reinforced graphite sheet at CL600, and a 316L stainless steel spiral gasket with graphite filler paired with NR40 sheet for cryogenic valves, a combination chosen to withstand the thermal cycling a cryogenic isolation valve experiences on every cool-down and warm-up.
Engineering Design of the Masoneilan 33000 Series
The Masoneilan 33000 Series spans an unusually wide size range from 3 to 48 inches (DN 80 to DN 1200), rated to ANSI Class 150, 300, and 600, with body materials including carbon steel (WCC/WCB), stainless steel (CF8M), low-temperature carbon steel (LCC) for cold service, and duplex or chrome-moly alloys available on request for corrosive or high-temperature applications. Standard-service valves operate across a broad –50°F to 650°F (–46°C to 343°C) range, while cryogenic variants with the extended bonnet and metal seat configuration are rated down to –320°F (–196°C) for LNG and industrial gas service.
Seven Star LLC packages the 33000 Series seal kit to the customer’s confirmed size, pressure class, and standard or cryogenic configuration, supplying the correct seat material, gland packing, and pressure-class-specific gasket as one traceable kit, so plant maintenance teams can complete a full seat and shaft-seal rebuild without discovering a gasket-class mismatch mid-job.
Key Features
This Masoneilan 33000 Series kit is engineered to restore full containment on an in-service triple offset butterfly valve. Key features include:
- Laminated soft-seat material with conical sealing geometry sized to the confirmed diameter of the customer’s Masoneilan 33000 Series valve.
- Metal-to-metal seat and extended bonnet hardware available for cryogenic service configurations.
- Passivated or braided graphite gland packing supplied for both standard and cryogenic shaft sealing.
- Pressure-class-specific gaskets: NR40 nickel-reinforced graphite (standard), SST100 tanged stainless reinforced graphite (CL600).
- 316L stainless steel spiral gasket with graphite filler paired with NR40 sheet for cryogenic valve configurations.
- Covers the full 3–48 inch size range across ANSI Class 150, 300, and 600.
- Kit contents cross-checked against the current Baker Hughes 33000 Series technical specification before dispatch.
- Supplied with reassembly guidance covering gland stud torque sequence to avoid uneven shaft loading.
Industrial Applications
The Masoneilan 33000 Series is specified across Middle East LNG terminals, refineries, and general isolation service wherever bubble-tight shutoff is required without the maintenance burden of a metal-seated ball or gate valve – cryogenic LNG loading and vaporization systems, refinery isolation and blowdown service, and large-diameter process isolation on petrochemical units. Facilities around Muscat, Sohar, and the Salalah free zone operating LNG or large-bore isolation systems schedule Masoneilan 33000 Series seat and gasket rebuilds into planned turnarounds, particularly on cryogenic units where correct gasket selection across thermal cycling is critical to maintaining zero-leakage performance.
Working closely with plant engineers in the region, Seven Star LLC supplies this Masoneilan 33000 Series seal kit to reliability and instrumentation teams across the Sultanate of Oman and the broader GCC, supporting LNG, refining, and petrochemical facilities that depend on this platform’s triple-offset design for long-life, low-maintenance isolation. Seven Star LLC’s manufacturer-verified sourcing ensures the correct seat material and pressure-class-specific gasket are supplied for the confirmed valve configuration.
Technical Specifications
Representative build data for the Masoneilan 33000 Series platform this kit is engineered to match:
| Parameter | Specification |
|---|---|
| Model | Masoneilan 33000 Series |
| Valve Type | Triple offset butterfly valve |
| Sizes Covered | 3–48 inch (DN 80–1200) |
| Pressure Classes | ANSI Class 150, 300, 600 |
| Standard Seat | Laminated soft seat, conical sealing geometry |
| Cryogenic Seat | Metal-to-metal, extended bonnet |
| Gland Packing | Passivated or braided graphite |
| Gaskets | NR40 (standard); SST100 (CL600); 316L spiral + NR40 (cryogenic) |
| Temperature Range | –50°F to 650°F standard; to –320°F cryogenic |
Request a Quote for Masoneilan 33000 Series Triple Offset Butterfly Valve Seal Kit
Seven Star LLC invites facility engineers, procurement leads, and maintenance planners across Oman and the GCC to submit a formal RFQ for the Masoneilan 33000 Series triple offset butterfly valve seal kit with the valve’s confirmed size, pressure class, and standard or cryogenic configuration, so the correct kit is engineered without guesswork. Seven Star LLC supplies common 33000 Series soft-good variants on request, can furnish the current Baker Hughes technical datasheet on request, and can connect customers with its instrumentation division for turnaround planning. With fast quotation turnaround and technical support, Seven Star LLC backs every Masoneilan 33000 Series kit with manufacturer traceability and warranty support.
Browse the full Masoneilan range or see more Control Valves products supplied by Seven Star LLC in Oman and the GCC.
Masoneilan control valves and actuator series
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Throttling duty on steam, hydrocarbons, gas and water is the daily work of these valves: feedwater and steam conditioning in power plants, separator and compressor loops in gas processing, high pressure drop letdown, cryogenic service in LNG and air separation, and general flow, pressure and level control in refineries and chemical plants.Ordering Masoneilan valves and spare parts: what we need
For spare parts the serial number is decisive, since the factory record behind it lists trim, materials and actuator. Send a clear nameplate photo with serial number, model number, size and pressure class. For a new valve add the process data: fluid, inlet and outlet pressure, temperature, minimum, normal and maximum flow, required leakage class, fail position, air supply and control signal.Browse Masoneilan products by category: Control Valves, Valve Actuator, Regulators, Valve Positioner, Level Transmitter.
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