The Double Block and Bleed Plug Valve (DBBV) is a single valve solution used to replace two in-line valves with a drain or bleed valve. Many different valve types have been used in the double configuration for blocking and bleeding, sampling, or draining. Traditional solutions can result in loss of product, frequent maintenance, and even failure.

The following benefits arise from using a single valve solution:

• • • Space + weight requirement reduction
    • Shorter drain times
    • One actuator instead of two

Control Seal DBBV has two seated surfaces (slips). When the valve is in a closed position, each seal is fully isolated, not allowing any leakage from downstream, upstream, or the body cavity. A thermal relief vent / bleeds the body cavity when overpressure occurs, so the downstream pipeline is fully isolated from upstream pressure without the need for pressure balancing.

Compared to other DBB valves, Double Block and Bleed Plug Valves have the Double Isolation and Bleed function (DIB). Therefore, it provides double security because they have two seals that are independent of each other.

• • • 100% tight shut-off (zero leakage). Dual Expanding, proven zero leakage both up and downstream.
    • Mechanically energized sealing without springs to obtain sealing.
    • Friction-free opening and closing, eliminating contact between slip seals and seating area during rotation.   
    • Non-lubricated sealing ­media—specific soft seal material.
    • The self-locking operating mechanism on all Control Seal valves secures the closing member from rotating due to in-line forces. As a result, there is no danger of line slam or shock.

Control Seal Expanding Plug Valves come with a unique HELIXTRUNNION™ rotating mechanism.

• • • Smaller envelope due to no stem guiding groove, no stem guides (compared to conventional design), and trunnion placed inside the valve body, reducing the lower plate size.
    • Fast opening and closing due to a robust rotating mechanism.
    • The valve is maintenance-friendly as the rotating mechanism is inside the valve. Stem guides and gland packings are outside the pressurized area and can be adjusted while the valve is in service. All valves are executed with a back seat.
    • Fewer moving parts lead to extended life and fewer spare parts needed. 
    • No stem guiding groove and stem guides as in conventional helical groove stem design—no need for lubrication of the stem guides.

The bleed system’s function is to prove tight shutoff and relieve pressure inside the body cavity. The following options are available (and more on request):