Welded ball valve with durable construction, ideal for high-pressure piping systems. Perfect for rel.
Fully Welded Ball Valve
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ASTM A193 B8M Hex Bolt
ASTM A193 B8M Hex Bolt
High-performance trunnion mounted ball valve for industrial piping systems.

Double Block and Bleed (DBB) Valves

Qisheng Double Block and Bleed (DBB) Valves provide a space-saving and safer alternative to multiple valve manifolds. By integrating two independent seats and a central bleed point into a single valve body, they allow for absolute isolation and safe cavity venting. Designed for high-integrity services in oil refineries and chemical plants, our DBB valves reduce potential leak points, minimize footprint, and fully conform to API 6D fire-safe and anti-static standards.

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Description

Qisheng Double Block and Bleed (DBB) Ball Valve

The Qisheng DBB Ball Valve offers a superior isolation solution that combines two independent sealing surfaces and a bleed mechanism into a single, high-integrity unit. This specialized configuration allows operators to isolate both the upstream and downstream sections of a pipeline simultaneously. By venting the central cavity, users can verify seat integrity and safely perform maintenance without shutting down the entire system, providing a safer and more efficient alternative to traditional multi-valve manifolds.

Critical High-Integrity Features

  • Manifold Consolidation: Replaces the complex “two-valves-plus-a-spool” setup, significantly reducing the number of potential leak paths and overall system weight.
  • Cavity Venting & Draining: Features standard vent and drain ports that allow for the safe removal of trapped fluids and pressure before maintenance.
  • Bi-Directional Sealing: Both seats act independently to provide positive shut-off from either direction, ensuring maximum isolation reliability.
  • Fire-Safe & Anti-Blowout: Conforms to API 6FA/607 fire-testing standards and features an anti-blowout stem for extreme pressure safety.
  • DIB-1 & DIB-2 Options: Available with Double Isolation and Bleed configurations to meet specific double-sealing requirements for hazardous media.

Technical & Material Specs

  • Design Standard: API 6D
  • Sealing Type: Soft Seat or Metal Seated for harsh/abrasive conditions
  • Pressure Ratings: Class 150 up to Class 2500
  • Applications: Oil and gas refineries, chemical dosing, offshore manifolds, and instrument isolation.
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