Double Block & Bleed Compact Manifold
DBB Compact Manifold
Two shut-off valves and one bleed point are built into a single body. This saves piping space and reduces the number of outside connections in marine, offshore, oil, gas, LNG and chemical service.
Why Use a Compact DBB Manifold
Replace Two Separate Valves with One Compact Unit
One body takes the place of two separate valves and the pipe between them. This can reduce weight, save installation space and leave fewer outside joints to install and inspect.
Integrated DBB Manifold
Two ball valves and a bleed connection are built into one cast or forged body. Trunnion-mounted models can also release excess pressure trapped inside the valve body.
Traditional Twin-Valve Assembly
Two separate valves need a connecting pipe and more flange or weld joints. This takes more room and creates more connections to install, inspect and maintain.
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Choose the Right Design
Floating Ball or Trunnion-Mounted Ball
Choose the design based on valve size, pressure class, working temperature and how the line must be isolated.
Floating Ball Valve
Line pressure pushes the floating ball against the downstream seat. This design is suitable for general shut-off service. For higher pressure or full double block and bleed duty, use the trunnion-mounted design.
- Pressure Class
- ASME Class 150–600
- Temperature
- -29°C to 200°C, soft seated
-29°C to 350°C, metal seated - Typical Duty
- General shut-off service
- Actuation
- Manual, pneumatic, electric or hydraulic
Trunnion Mounted Ball Valve
The ball is supported at the top and bottom, so it stays stable under higher pressure. Spring-loaded seats provide sealing, and the valve includes a separate bleed connection and cavity pressure relief.
- Pressure Class
- ASME Class 150–2500
- Temperature
- -29°C to 200°C, soft seated
-29°C to 350°C, metal seated - Typical Duty
- High-pressure and important isolation points
- Actuation
- Manual, pneumatic, electric or hydraulic
Safety Features
Features That Help Protect the Valve and Pipeline
These features help control trapped pressure, keep the stem in place, reduce static build-up and provide backup sealing when needed.
Blow-out Proof Stem
The stem is fitted from inside the body, so line pressure cannot push it out. It also provides a second sealing point.
Anti-static Device
A spring-loaded contact connects the ball, stem and body to help discharge static electricity.
Cavity Pressure Relief
On trunnion-mounted models, excess pressure trapped inside the body can be released back to the pipeline.
Double Block & Bleed
The two shut-off points isolate the line, while the bleed or drain connection lets operators release pressure from the space between them.
Emergency Sealant Injection
Sealant injection fittings are standard on trunnion models NPS 6 and larger. They can also be supplied on smaller sizes when requested.
Fire-safe Construction
Floating and trunnion-mounted versions can be supplied to API 607 fire-safe requirements.
Technical Specifications
Sizes, Pressure Classes and Available Options
| Size Range | NPS 2–24, DN 50–600 |
|---|---|
| Pressure Class | Floating: ASME Class 150–600; Trunnion: ASME Class 150–2500 |
| Temperature Range | -29°C to 200°C with soft seats; up to 350°C with trunnion metal seats |
| End Connections | Socket weld ASME B16.11; butt weld ASME B16.25; NPT threaded ASME B1.20.1; flanged ASME B16.5 up to 24 inches, with ASME B16.47 used for larger project-specific sizes |
| Port Bore | Full bore or reduced bore |
| Seat / Sealing | Soft seated as standard; Metal seated available as an option |
| Body Materials | Cast or forged carbon steel, stainless steel and duplex stainless steel; material grades selected to project and service requirements |
| Operation | Lever, gear, pneumatic actuator, electric actuator or hydraulic actuator |
| Construction Options | Three-piece, extended neck and project-specific custom configuration |
Cast or Forged Carbon Steel
Available in cast and forged grades for oil, gas, water and other fluids that do not require a corrosion-resistant body.
Cast or Forged Stainless Steel
Available in cast and forged grades where better corrosion resistance is needed, including many chemical and marine applications.
Cast or Forged Duplex Stainless Steel
Multiple duplex and super duplex grades are available for higher strength and improved resistance to chloride corrosion in seawater and offshore service.
Applications
Where the DBB Compact Manifold Is Used
FPSO & Tankers
Used for cargo, tank-cleaning and process lines where lower weight and a smaller installation area are helpful.
Production Platforms
Used to isolate topside process lines before inspection, draining or maintenance.
Subsea Manifolds
Trunnion-mounted and metal-seated options are available for high-pressure production lines.
Offshore Wind & Terminals
Suitable for hydraulic, cooling and loading systems where piping space is limited.
Standards and Test Documents
Standards, Testing and Documents Available
FAQ
Common Questions About DBB Compact Manifolds
How is a compact DBB manifold different from a twin-valve assembly?
When should a trunnion-mounted design be specified?
Which material is suitable for seawater service?
What information is needed for a quotation?
Request a Quote
Send Us Your DBB Manifold Requirements
Send the size, pressure class, material, end connection, fluid, temperature, quantity and test requirements. Our team will check the details and prepare a quotation.
