The Neles 6D Series soft-seated trunnion-mounted ball valve is a full-bore ball valve certified to API 6D and capable of pigging. It features spring-loaded single-piston-effect (SPE) seats, supports double block and bleed (DBB) and cavity relief, and incorporates Fire-Tite fire-safe dual barriers, a blowout-proof stem, and antistatic construction. It is designed for sectional isolation in oil and gas transmission pipelines, reliable isolation and pressure management at pipeline stations, as well as process service in refineries, petrochemical plants, and emergency isolation valve applications.
Neles soft-seated trunnion-mounted ball valve, 6D Series
Neles
Neles 6D Series Soft-Seated Trunnion-Mounted Ball Valve
Full-bore soft-seated trunnion-mounted ball valve for pipeline isolation and pigging, with an optional API 6DX interface.
- Category
- Ball Valves
- Valve Type
- Full-bore soft-seated trunnion-mounted ball valve
- Pigging Capability
- Piggable
Specifications
- Valve Type
- Full-bore soft-seated trunnion-mounted ball valve
- Pigging Capability
- Piggable
- Seat Design
- Spring-loaded single-piston-effect (SPE) seats with double block and bleed (DBB) design
- Valve Cavity Relief
- DBB seats support cavity relief in the closed position
- Primary Sealing Arrangement
- Self-relieving soft-seated primary valve seat with secondary pressure-assisted metal seal (PSSM)
- Fire-Safe Sealing Performance
- Fire-Tite design with dual barriers consisting of O-ring/lip seals and graphite seals
- Body Sealing
- Primary O-ring seal and secondary graphite gasket seal
- Seat Spring Material
- Nickel alloy Inconel X-750
- Stem Construction
- Integral internally mounted stem with blowout-proof design
- Antistatic Construction
- Antistatic connections between the ball and stem and between the stem and body
- Design and Manufacturing Standards
- ASME Section VIII, ASME B16.34
- Industry Certification
- API 6D certification, certificate no. 6D-2173
- Actuator Interface
- Optional API 6DX-compliant configuration
- Emergency Sealant Injection
- Optional emergency seat and stem sealant injection devices
Application scenarios
Oil and Gas Transmission Pipeline Isolation and Pigging
Used for sectional shutoff and maintenance isolation in oil and gas transmission pipelines. The valve features a full-bore, piggable design and API 6D certification, making it suitable for pipeline applications requiring pigging and reliable isolation.
Double Block and Bleed in Oil and Gas Pipelines and Stations
Used in process sections of oil and gas pipelines, gathering facilities, and stations requiring highly reliable isolation and body cavity pressure management. The spring-loaded single-piston-effect seats support double block and bleed and allow body cavity bleeding when the valve is closed.
Process Isolation in Refining and Petrochemical Plants
Used to isolate hydrocarbon process pipelines and equipment in refining and petrochemical plants. The valve uses soft-seated primary and secondary metal sealing structures, body sealing consisting of O-rings and graphite gaskets, and a Fire-Tite fire-safe sealing design.
Emergency Isolation Valve Positions in Oil and Gas and Refining Facilities
Used in emergency isolation valve positions in oil and gas pipelines, oil and gas processing facilities, and refining and petrochemical plants. The valve can be equipped with an optional API 6DX-compliant actuator interface and features an integral internal blowout-proof stem, anti-static connections, and a Fire-Tite fire-safe sealing structure.
Selection points
SPE Single-Piston Effect and DBB Double Block and Bleed
Uses spring-loaded single-piston-effect seats and supports double block and bleed as well as cavity relief in the closed position.
Self-Relieving Soft Seat and Secondary Metal Seal
The primary seat uses a self-relieving soft-sealing design with a secondary metal seal PSSM.
Fire-Tite Dual-Barrier Fire-Safe Sealing
The Fire-Tite design uses O-ring or lip seals together with graphite seals to form a dual sealing barrier.
Inconel X-750 Seat Springs
The seat springs are made of nickel alloy Inconel X-750.
Integral Internally Mounted Blowout-Proof Stem and Antistatic Construction
Features an integral internally mounted blowout-proof stem, with antistatic connections between the ball and stem and between the stem and body.
Installation notes
Confirm Cavity Relief Position
This valve uses a double block and bleed design and supports cavity relief only in the closed position. Confirm that the valve is closed before performing cavity relief.
Verify Emergency Sealant Injection Device Configuration
The valve can be equipped with optional emergency seat and stem sealant injection devices. Verify whether the actual valve includes these devices before installation or maintenance.
FAQ
What isolation and pipeline applications are suitable for the Neles 6D Series trunnion-mounted ball valve?
The Neles 6D Series is a full-bore, piggable trunnion-mounted ball valve suitable for isolation applications requiring reliable shutoff, low flow-friction losses, and pig passage. Its modular construction allows the appropriate valve trim to be selected for the actual application conditions. The specific configuration must be confirmed based on the actual model and service conditions.
What benefits do the full-bore and piggable designs of this ball valve provide for process operation?
The full-bore, machined internal flow passage helps reduce flow-induced friction losses and allows a pig to pass through the valve. This design is suitable for process systems that require pipeline cleanliness, continuous media transport, and pressure-drop control.
How does the Neles 6D Series achieve seat sealing and cavity relief?
This series uses spring-loaded single-piston-effect (SPE) seats and a double block and bleed (DBB) design. The seats accommodate pressure, thermal shock, and wear. When the valve is closed, the DBB seats allow the cavity to be relieved. Nickel-alloy helical springs behind the seats maintain uniform and stable seat sealing performance under low-pressure conditions.
What sealing design features does this valve offer under thermal shock, fire, and similar service conditions?
The valve body uses a dual-sealing design, with an O-ring as the primary seal and a graphite gasket as the secondary seal, together with a robust spiral-wound graphite gasket to maintain high-pressure sealing integrity. The valve also uses a self-relieving primary soft seal and a secondary metal seal (PSSM), combined with dual-barrier O-ring or lip seals and graphite seals to provide Fire-Tite performance.
What configuration features should be considered during selection, installation, and maintenance of the Neles 6D Series?
The valve body is supplied with a cavity vent port and a bottom drain port to facilitate cavity-related operations. The valve is equipped with lifting hooks and mounting brackets for safe lifting and handling. Installation hardware uses high-strength couplings and guide bearings to transmit torque between the valve and different types of actuators. For applications requiring improved field maintainability, the optional emergency seat and stem sealant injection devices can be evaluated. The specific configuration must be confirmed based on the actual model and service conditions.