Overview

The double block and bleed valve (also known as double seal guided valve or general valve) is a type of valve that opens or closes the fluid passage through the compound motion of a tapered or cylindrical plug guided along a track, and is equipped with dual sealing and double block and bleed functions. The valve adopts a straight-through structure, with a through-type medium flow port provided on the plug. During operation, the plug first rises along the guide track to disengage the sealing surfaces, then rotates 90 degrees so that the flow port aligns with or becomes perpendicular to the valve body passage, thereby achieving fully open or fully closed positions. For closing, the plug first rotates then lowers to force the sealing surfaces together. The valve stem is integrally or fixedly connected to the plug. During operation, the stem and plug rotate and lift synchronously. Packing sealing is provided between the stem and the valve body to ensure reliable external sealing. The valve body is designed with upper and lower sealing pairs, forming a double sealing barrier in the closed position, and a bleed port is provided in the middle of the valve body for medium discharge or pressure monitoring between the two seals, achieving double block and bleed functionality. The plug moves along a precision guide track, and there is no friction or wear on the sealing surfaces during opening and closing, significantly extending service life. The valve relies on precise fit and guide track guidance between the plug and the valve body sealing surfaces to achieve sealing, offering low operating torque and stable sealing performance. It is widely used in demanding pipeline systems in petroleum, natural gas, chemical and other industries for shut-off, isolation or bleed applications.

Double Block and Bleed Valve、Double Sealing Guided Valve、Master Valve Product Diagram

Feature

1 . Double Block and Bleed for Maximum Safety: The valve features upper and lower independent sealing pairs, forming a double sealing barrier in the closed position. A bleed port is provided in the middle of the valve body for medium discharge or pressure monitoring between the two seals, ensuring zero-leakage safety.

2 . Guide Track Guidance for Frictionless Opening/Closing: The plug moves along a precision guide track. During opening, the plug first rises to disengage the sealing surfaces before rotation; during closing, the plug first rotates then lowers for forced sealing. There is no friction or wear on the sealing surfaces, significantly extending service life.

3 . Forced Sealing with Zero Leakage: During closing, a wedging mechanism or guide track descent generates a forced sealing force, ensuring metal hard sealing meets zero-leakage standards, suitable for demanding applications with high temperature, high pressure, and particulate-laden media.

4 . Corrosion and Wear Resistance: The valve body and plug can be made of carbon steel, stainless steel, alloy steel, or other materials depending on the medium. Sealing surfaces can be hardened (e.g., hardfacing with cemented carbide, nitriding, etc.), providing wear resistance, erosion resistance, and long service life.

5 . Combined Lifting and Rotating Motion with Compact Height: The stem and plug rotate and lift as an integrated unit, offering a compact structure with low overall height, suitable for pipeline systems with limited installation space.6 . Bidirectional Sealing with No Flow Direction Restriction: The valve is designed for bidirectional sealing with no strict requirement on flow direction, offering greater installation flexibility and suitability for various pipeline layouts.