Double Block and Bleed Plug Valve Manufacturer - KFTE

Industries for Double Block and Bleed Plug Valve

Double Block and Bleed (DBB) plug valves are critical for ensuring safety and isolation in high-risk environments. Below are the key industries where these valves are prominently used

1. Oil & Gas

Applications include pipelines, refineries, and gas distribution systems. DBB plug valves ensure isolation during maintenance and emergency shutdowns, meeting standards like API 6D and ISO 10423.

2. Chemical & Petrochemical

Used for handling corrosive media, solvents, and hydrocarbons. KFTE's DBB valves are designed for chemical and petroleum industries, offering leak-tight isolation during processes .

3. Power Generation

Thermal power plants and gas turbines rely on DBB plug valves for quick-closing safety mechanisms.

4. Biogas & Landfill Gas

KFTE's DBB plug valves are explicitly designed for biogas and landfill gas systems, ensuring safe control and isolation of gas flows.

5. Pharmaceutical & Paper Manufacturing

KFTE's DBB plug valves are applied in pharmaceutical and paper industries, adhering to strict hygiene and safety standards.

6. Smelting & Metallurgy

High-temperature and high-pressure environments in smelting operations utilize DBB plug valves for reliable isolation.

7. Urban Construction & Infrastructure

Pipeline systems and municipal gas distribution networks employ DBB plug valves for safety and regulatory compliance.

Components of Double Block and Bleed Plug Valve

A Double Block and Bleed (DBB) plug valve is engineered to provide two independent seals (blocks) and a bleed port to safely isolate and vent trapped fluids. Below are its key components and their functions:

1. Body

• The main housing, typically made of cast steel, stainless steel, or corrosion-resistant alloys.

• Designed to withstand high pressure, temperature, and corrosive media.

• Contains inlet, outlet, and bleed port connections.

2. Plug

• A cylindrical or conical rotating element with a flow passage.

• Rotates 90° to open/close flow. In the closed position, it creates two sealing points (double block).

• Often coated or hardened for wear resistance (e.g., tungsten carbide).

3. Seats

• Two annular sealing surfaces (upper and lower) that interface with the plug.

• Provide the primary and secondary blocks to prevent leakage.

• Made of resilient materials like PTFE, reinforced elastomers, or metal for high-temperature applications.

4. Stem

• Connects the plug to the actuator or handle.

• Transmits rotational force to the plug.

• Sealed with packing (e.g., graphite) to prevent stem leakage.

5. Actuator

• Manual (lever/handwheel), pneumatic, hydraulic, or electric mechanism for valve operation.

• Enables quick closure (critical for emergency shutdowns in industries like oil and gas).

6. Bleed/Vent Port

• A small valve or port located between the two sealing surfaces.

• Allows trapped pressure/fluid between the blocks to be safely drained or sampled.

• Ensures zero leakage during maintenance.

7. Seals and Gaskets

• Secondary sealing elements (e.g., O-rings, lip seals) to enhance leak-tight performance.

• Resistant to chemical degradation and temperature extremes.

8. End Connections

• Flanged, threaded, or welded ends for pipeline integration.

• Compliant with industry standards (e.g., ASME B16.5 for flanges).

9. Bonnet

• Covers the stem and seals the top of the valve body.

• Bolted or threaded for easy maintenance access.

10. Lubrication System (Optional)

• Some plug valves include grease fittings to inject lubricant between the plug and seats.

• Reduces friction and enhances sealing in abrasive or high-pressure applications.