Designed to combine two shut-off valves and one bleed valve into a single body, the DBB valve provides reliable positive isolation — minimizing leak paths, saving space, and enhancing operational safety across oil, gas, petrochemical, and instrumentation applications.
A Double Block and Bleed (DBB) Ball Valve is a specialized valve designed to provide positive isolation within a piping system.
It consists of two isolation seats and a bleed cavity in between — allowing operators to block flow from both upstream and downstream sides, then safely bleed or vent the cavity to confirm zero leakage.
In essence, a DBB valve combines the function of two shut-off valves and one bleed valve into a single, compact unit.
When both seats are closed, fluid pressure is blocked from entering the cavity between them.
By opening the bleed port, trapped pressure or residual fluid can be released, ensuring complete isolation.
This design enhances both safety and operational efficiency, reducing the number of components and potential leak paths.
· Enhanced Safety: Provides reliable isolation for maintenance, calibration, or line modification.
· Reduced Installation Space: Combines multiple valves into one compact assembly.
· Lower Leak Risk: Fewer connections mean fewer potential leak points.
· Ease of Maintenance: The bleed port allows safe pressure relief and contamination check.
· Operational Efficiency: Speeds up testing, draining, or line replacement processes.
DBB ball valves are widely used in:
· Oil & Gas and Petrochemical Plants – for pipeline isolation and instrument calibration.
· Refineries and Process Systems – for safe maintenance and pressure testing.
· Power Generation and Energy Systems – for steam, condensate, or hydraulic isolation.
· Instrumentation and Measurement Lines – for ensuring system integrity during operation.
At Anson Flow, we manufacture high-performance DBB ball valves built for durability, precision, and long-term reliability.
Our DBB designs feature:
· Full or Reduced Bore Options
· Forged or Bar Stock Construction (A105, SS316, Duplex, etc.)
· API 6D, ASME B16.34, and EN 10204 3.1 Compliance
· Optional Metal-Seated or Soft-Seated Configurations
Every DBB valve is zero-leak tested to ensure absolute safety and performance, delivering dependable isolation for critical oil, gas, and instrumentation systems worldwide.
Not sure which DBB configuration fits your project?
Our valve specialists can recommend the right model based on your pressure class, media type, and installation requirements.
📩 Contact us: sales@ansonflow.com
Learn more about our standard and custom-engineered valve solutions at www.ansonflow.com.