TWIN BALL DOUBLE BLOCK AND BLEED TRUNNION BALL VALVES
High-performance valves engineered for the oil & gas, chemical, petrochemical, water, and energy industries
Negri Fratelli Twin Ball Double Block and Bleed trunnion-mounted ball valves are designed to ensure maximum safety, reliability and ease of maintenance, even in critical or high-pressure installations. The twin ball design provides complete shut-off in both directions and allows venting of the internal cavity.
These valves are used in a wide range of applications, including pipelines, refineries, large power plants, industrial water treatment systems and process lines where operational continuity and safety are essential
- Bolted body
- Full or reduced bore options
- Double Block and Bleed function – twin ball design with two independent isolation points and cavity venting (through a bleed valve or plug), to drain the fluid trapped between the balls
- Bi-directional sealing with Double Block & Bleed (DBB) design
- Solid ball with a cylindrical bore and no internal cavities
- Single-piston seats with self-relieving effect
- Anti-ejection stem with antistatic device
- Multiple actuation options – manual lever or gearbox (with handwheel or 90° deviation), or actuator-operated
- Testing – hydrostatic and pneumatic tests to API 6D. Other testing upon request
- Firesafe certified design – API 607 and ISO 10497 compliant
- Double piston effect seats, DIB-1 / DIB-2 seats, metal-to-metal sealing
- Stem and seat sealant injection systems
- Drain and vent devices, complete with ball valve and/or plug, for DBB testing and maintenance
- Versions for cryogenic or high-temperature service
- Locking devices
- Design standards: API 6D, ASME B16.34, ASME VIII DIV. 1 / 2, NACE MR0175, EN ISO 14313, EN ISO 17292
- Pressure rating: ASME 150 to ASME 2500, PN 6 to PN 420
- Temperature range: –29°C to +160°C (other ranges on request)
- Size range: up to DN 400 (16”)
- End connections: flanged, butt-welding, hub
- Body and closures: in carbon and stainless steel, obtained from forging or bar stock
- Ball and seat rings: ASTM A350 Gr. LF2, ASTM A479 S31600, ASTM A182 F316 (other materials on request)
- Seat inserts: soft (thermoplastic polymers such as RPTFE, Devlon, Peek, or PCTFE) or metal (Tungsten/Chrome Carbide coating), other materials on request
- Seals: FKM, HNBR, FFKM, EPDM, graphite, lip seals, and special high-temperature graphite seals (other materials and solutions available on request)
- Design & Construction: API 6D
- Firesafe: API 607, EN ISO 10497
- Pressure Equipment Directive (PED): 2014/68/EU
- ATEX certification: 2014/34/EU