Stainless Steel Expanding DBB Plug Valve

The Stainless Steel Expanding Double Block and Bleed (DBB) Plug Valve is engineered for safe, reliable, and zero-leakage isolation in demanding pipeline systems. Utilizing an advanced mechanical expanding plug structure, the valve provides simultaneous upstream and downstream sealing with an independent cavity bleed function. This ensures maximum safety during critical operations such as maintenance, shutdown, and system isolation.

Zero-Leakage Sealing: The expanding plug mechanism ensures a tight, bubble-tight shutoff compliant with API 598 / ISO 5208 Rate A, even under high pressure differentials.
Corrosive & Sour Service Ready: Premium stainless steel and duplex construction offers excellent resistance to seawater, sour gas ($H_2S$), and aggressive chemical media. Fully compliant with NACE MR0175 / MR0103.

High Safety Integrity Design: Engineered to meet API 6D specifications, featuring a certified fire-safe structure (API 607 / 6FA) and an anti-blowout stem design.
Low Maintenance & Long Service Life: The robust internal structure eliminates continuous seat wear during 90-degree rotation, significantly reducing downtime and overall operational costs (OPEX).
Severe Service Capability: Perfectly suited for high-pressure, high-temperature, and erosive fluid conditions.

The valve operates through a precisely controlled, friction-free mechanical expansion system:
Frictionless Rotation: The plug rotates 90 degrees into the closed position without contacting the valve seats, preventing premature wear or scratching of the sealing surfaces.
Mechanical Expansion: Once fully positioned, the internal wedge mechanism forces the plug segments outward, expanding them tightly against the valve body.
Dual Tight Sealing: The expanded plug seals against both upstream and downstream seats simultaneously, achieving true double isolation.
Bleed & Verification: The cavity between the sealing surfaces is vented through the bleed valve. This allows operators to verify zero pressure and ensure 100% safe isolation before downstream work begins.

Our internal quality manual strictly enforces a zero-defect policy. Every single valve undergoes rigorous quality control and testing before leaving our facility. Material Test Reports (MTR) according to EN 10204 3.1 are provided with all shipments.
100% Pressure Testing: Hydrostatic shell and seat testing compliant with API 6D and API 598.
Pneumatic Testing: Low-pressure gas shell & seat leakage testing for gas-tight verification.
Non-Destructive Testing (NDT): RT, UT, PT, and MT available based on project specifications.
Third-Party Inspection (TPI): We fully support and welcome inspections by SGS, Bureau Veritas (BV), TÜV, or other client-nominated international agencies.

As a professional industrial valve manufacturer, we offer end-to-end engineering support for global EPC projects and bulk procurement:
Advanced Production: Our machine shops are equipped with high-precision CNC machining centers (Mazak / Toshiba) and dedicated valve pressure testing labs.
Tailored Engineering: Customized pressure classes, special alloys (Monel, Inconel, Hastelloy), and extended stems for insulated or buried service.
Actuation Solutions: Complete integration with pneumatic, electric, or hydraulic actuators, including full control accessories (limit switches, solenoid valves, positioners).
OEM & Drawing Support: Full private labeling services and 2D/3D CAD drawing support for engineering approval (MDS/VDR) phases.

Our Expanding DBB Plug Valves are field-proven in critical global locations. Our recent track record includes supplying over 300 units of custom DBB valves to a major oil and gas pipeline system in the Middle East, as well as multiple installations in LNG storage facilities across Southeast Asia.
Key Applications
Oil & Gas transmission pipelines and custody transfer metering stations.
Refinery process units, product manifolds, and tank farm isolation.
LNG terminals, storage systems, and cryogenic processing.
High-pressure industrial utility pipelines and offshore production platforms.