Zhejiang Demelong Fluid Technology Co., Ltd.: Your Professional Double Block and Bleed Plug Valve Manufacturer!
Zhejiang Demelong Fluid Technology Co., Ltd. (DMLV) is a leading industrial valve Manufacturer headquartered in Wenzhou, China. We specialize in the design, development, and production of high‑performance plug valves and flow control solutions for diverse industries such as petrochemical, power generation, wastewater treatment, oil & gas, and industrial fluid systems.
Quality Control
We manage the entire production process, from raw material procurement to final inspection. Each valve undergoes rigorous quality inspection to ensure stable performance, durability, and compliance with international standards.
Customization Available
We support customization based on drawings or samples, meeting non-standard sizes, materials, and coating requirements to suit specific operating conditions.
Advanced Production Equipment
We possess advanced equipment including automatic internal and external cylindrical grinding CNC vertical lathes, CNC machine tools, valve grinding machines, and intelligent universal drive motors.
Wide Range of Applications
Our products are widely used in industries such as petroleum, chemical, natural gas, pharmaceutical, power, and construction.
-
![Pneumatic Actuated Non-Lubricated DBB Valve]()
Pneumatic Actuated Non-Lubricated DBB ValveThe Pneumatic Actuated Non-Lubricated DBB Valve is engineered for critical isolation and safety-venting applications. By combining two independent sealing barriers with an intermediate bleed system -
![Stainless Steel Non-Lubricated DBB Valve]()
Stainless Steel Non-Lubricated DBB ValveOur non-lubricated Double Block & Bleed (DBB) valve integrates two independent sealing barriers and a central bleed port within a single, compact body. This engineered design allows operators to -
![Carbon Steel Soft Seat DBB Plug Valve]()
Carbon Steel Soft Seat DBB Plug ValveThe Carbon Steel Soft Seat Double Block and Bleed (DBB) Plug Valve is engineered for high-integrity, bubble-tight shutoff in critical industrial piping systems. Utilizing a quarter-turn plug -
![Flanged Soft Sealing Non-Lubricated Valve]()
Flanged Soft Sealing Non-Lubricated ValveThe Flanged Soft Sealing Non-Lubricated Plug Valve is engineered for heavy-duty, reliable flow isolation in severe process environments. Utilizing a premium resilient soft seat combined with a -
![Non-Lubricated Soft Seat DBB Plug Valve]()
Non-Lubricated Soft Seat DBB Plug ValveNon-Lubricated soft seat DBB plug valve operates on a precise quarter-turn rotary motion. The tapered or cylindrical plug rotates smoothly inside a premium polymer-lined sleeve. This design achieves -
![Soft Sealing Non-Lubricated DBB Plug Valve]()
Soft Sealing Non-Lubricated DBB Plug ValveOur Soft Sealing Non-Lubricated DBB (Double Block and Bleed) Plug Valve is engineered to deliver bubble-tight isolation, zero-leakage shutoff, and maintenance-free operation in demanding upstream, -
![Stainless Steel Inverted DBB Plug Valve]()
Stainless Steel Inverted DBB Plug ValveThe Stainless Steel Inverted DBB (Double Block and Bleed) Plug Valve is a high-performance industrial valve engineered to deliver absolute dual isolation with an integrated safety bleed function -
![Carbon Steel Pressure Balanced DBB Valve]()
Carbon Steel Pressure Balanced DBB ValveThe Carbon Steel Pressure Balanced Double Block and Bleed (DBB) Plug Valve provides robust, space-saving isolation for critical oil, gas, and process pipelines. By integrating two independent seating -
![High-Pressure Pressure Balanced Plug Valve]()
High-Pressure Pressure Balanced Plug ValveThe High-Pressure Pressure Balanced Plug Valve is engineered for heavy-duty isolation in high-pressure, high-temperature (HPHT), and severe service environments. -
![Double Block And Bleed Pressure Balanced Plug Valve]()
Double Block And Bleed Pressure Balanced Plug ValveIts advanced pressure-balanced plug design equalizes internal pressure across the plug, ensuring smooth quarter-turn operation with low operating torque, even under high differential pressure -
![Inverted Pressure Balanced DBB Plug Valve]()
Inverted Pressure Balanced DBB Plug ValveThe Inverted Pressure Balanced Double Block & Bleed (DBB) Plug Valve is a high-integrity isolation valve designed for critical process applications where zero-leakage shutoff, safety, and reliability -
![Pressure Balanced DBB Plug Valve]()
Pressure Balanced DBB Plug ValveThe Pressure Balanced Double Block & Bleed (DBB) Plug Valve is a high-performance quarter-turn isolation valve engineered for critical pipeline and process service. It is designed specifically for
A Double Block and Bleed Plug Valve (DBB Plug Valve) is a quarter-turn isolation valve designed to provide two sealing barriers and one bleed function within a single valve body.
As a professional Double Block and Bleed Plug Valve Manufacturer, we supply valves designed for oil & gas pipelines, petrochemical plants, refining systems, and high-pressure industrial services where reliable isolation and safety verification are essential.
Features
Integrated Double Isolation Structure
The valve integrates two sealing surfaces and one bleed channel inside a single body.
Bubble-Tight Shut-Off
Independent sealing segments ensure reliable sealing even under fluctuating pressure conditions.
Reduced Wear During Operation
The sealing segments retract slightly during plug rotation, which reduces friction and prevents abrasion on sealing surfaces.
Compact Pipeline Design
Replacing multiple valves with a single DBB plug valve reduces installation space and simplifies pipeline layout.
Raw Material Inspection
Body and plug materials undergo chemical composition verification and mechanical strength testing to ensure compliance with project specifications.
Precision Machining
CNC machining controls critical tolerances for the plug, seats, and sealing surfaces, ensuring smooth rotation and accurate sealing.
Assembly and Functional Check
Technicians assemble sealing segments, plug components, and bleed systems. Each valve undergoes operational testing.
Pressure Testing
Every valve passes hydrostatic shell tests and seat leakage tests according to API and international testing standards.
Final Inspection
Inspection covers dimensions, coating quality, marking, and operational torque before packaging and shipment.
Customization Options
Material Options
Available materials include carbon steel, alloy steel, stainless steel, duplex stainless steel, and special alloys for corrosion resistance.
Size and Pressure Range
Typical production covers NPS 2″–36″ and ANSI Class 150–1500, suitable for high-pressure pipeline systems.
End Connection Options
Flanged, threaded, butt-weld, or socket-weld connections are available to match pipeline configurations.
Actuation Options
Manual lever, gear operator, pneumatic actuator, or electric actuator can be integrated depending on automation requirements.
Certificate
FAQ
Find professional double block and bleed plug valve manufacturers and suppliers in China here! With abundant experience, we warmly welcome you to buy high quality double block and bleed plug valve made in China here from our factory. Customized orders are welcome.
twin seal double block and bleed valve, double block bleed plug valve, Twin Seal Orbit Plug Valve
