In industrial valve systems, a high-quality blind plate valve ensures safe and efficient operation of equipment. It is suitable for gas pipelines in metallurgy, chemical processing, petroleum, and municipal systems, serving as an effective device for positive gas isolation.   Working Principle and Features The blind plate valve consists of left, center, and right valve bodies, a valve plate, shafts, a compensator, and two drive units (for clamping and travel respectively). The clamping mechanism uses a drive assembly to actuate a linkage system, enabling three lead screws to operate synchronously and press the valve bodies against the valve plate to achieve sealing. This design provides good synchronization and uniform sealing force distribution. Positioning rollers are installed along the outer lower edge of the valve plate to enhance sealing reliability and ensure overall stability and sealing accuracy during operation, thereby extending the service life of the valve.   Valve Operating Sequence The clamping drive unit actuates the crank and linkage mechanism, causing the lead screws to rotate synchronously and retract the center body from the sealing surfaces (release condition). Guide wheels installed on the center body move laterally and simultaneously drive the valve plate. When the valve bodies are fully opened, the valve plate is positioned between the sealing faces of the left and right bodies, and the sealing surfaces are completely disengaged. The plate drive unit is then activated. Through a lever arm mechanism, the valve plate rotates, bringing the blind plate into the pipeline position. The clamping drive unit is started again to fully clamp the valve plate, completing valve closure.   Valve Opening The clamping drive unit first fully releases the valve bodies. The turning drive unit then rotates the valve plate so that the through-port aligns with the pipeline. Finally, the clamping electric actuator presses the valve plate to complete the opening operation.

Wide-body ball valves and single-piece ball valves are both types of ball valves used for controlling the on/off flow of medium in pipelines.   Both wide-body and single-piece ball valves feature a one-piece (integral) body design, unlike split-body designs. This differs from two-piece and three-piece ball valves, which have segmented valve bodies.   For internally threaded wide-body ball valves, the valve body is made from round or hexagonal stock, using either bar material or forged components. The ball core features a reduced-diameter design and is inserted from one side of the valve body. The stem uses an internal anti-blowout structure. Flat surfaces are machined on both the inlet and outlet sides of the body to facilitate assembly of the ball valve and allow the use of wrenches during pipeline installation.   In wide-body ball valves, the stem stuffing box is relatively shallow, and the internal packing volume is limited, resulting in a moderate sealing performance of the stem. Therefore, these valves are more suitable for low-pressure medium applications. In contrast, two-piece and three-piece ball valves feature stem stuffing box structures that provide reliable sealing for high-pressure medium applications.   The structure of flanged wide-body ball valves is essentially the same as that of internally threaded wide-body ball valves. Typically, the flange is connected to the intermediate valve body via threaded fasteners, although some designs utilize a forged one-piece structure.   Externally threaded wide-body ball valves can use a union-type structure, where the union is directly welded to the pipeline and connects to the external threads on the valve body. This design allows for easy disassembly and reassembly during valve maintenance or replacement without requiring separate unions on the pipeline.   The valve bodies of single-piece internally threaded ball valves and single-piece flanged ball valves are manufactured using casting processes, with the ball core featuring a reduced-diameter design. The stem uses an internal anti-blowout structure. The inlet and outlet ends of single-piece internally threaded ball valves have a hexagonal shape, similar to conventional internally threaded valves, to facilitate wrench operation and secure installation.   In single-piece flanged ball valves, the flange and valve body are cast as a single unit, eliminating the need to machine and assemble the flange separately as in wide-body flanged ball valves. This approach reduces cost and simplifies the manufacturing process.   Single-piece wafer-style ball valves have a shorter valve body length, making them more suitable for pipelines with limited space.   Wide-body and single-piece ball valves both use a reduced-diameter ball design, resulting in higher flow resistance compared with two-piece and three-piece ball valves. The main differences are as follows:   Valve Body Manufacturing Process ● Wide-bo...

In a wedge gate valve, the gate sealing surfaces are wedge-shaped, forming a specific angle relative to the gate centerline. The gate is driven downward by the valve stem to achieve closure. As the stem thrust increases, the normal force acting on the wedge-shaped sealing surfaces also increases, creating a forced sealing effect. This design significantly improves sealing performance under low-pressure conditions.   During opening, the gate sealing surfaces disengage from the seat immediately, which helps reduce wear on the sealing faces and extends the service life of the valve.   Applicable Standards for Wedge Gate Valves   Wedge gate valves are commonly manufactured in accordance with the following standards: ● GB/T 12234-2019 – Steel gate valves with bolted bonnet for petroleum and natural gas industries ● GB/T 12232-2005 – General-purpose flanged cast iron gate valves ● API Standard 600 (2015) – Steel gate valves for petroleum and natural gas industries   Types of Wedge Gate Valve Gates   Wedge gate valves are typically available in three gate configurations:Solid wedge gate, Flexible wedge gate, Double wedge gate.   The flexible wedge gate and double wedge gate rely on controlled deformation of the sealing surfaces to achieve improved contact with the valve seat. This design enhances sealing reliability and effectively prevents gate binding or jamming caused by temperature variations, ensuring smooth operation even under fluctuating thermal conditions.     Parallel Slide Gate Valve Design and Sealing Principle   In a parallel slide gate valve, the sealing surfaces at both the inlet and outlet ends of the gate are parallel to the gate centerline. For single-gate configurations, sealing is primarily achieved by the medium pushing a floating gate or floating seat into position. In double-gate configurations, sealing can be accomplished through springs or an expansion mechanism between the gates. Throughout the opening and closing process, the gate and seat sealing surfaces remain in constant contact, ensuring reliable sealing.   Applicable Standards for Parallel Slide Gate Valves   Common standards for parallel slide gate valves include: ● GB/T 23300-2009 – Parallel slide gate valves ● JB/T 5298-2016 – Steel parallel slide gate valves for pipelines ● API 6D – Pipeline valves for petroleum and natural gas industries   Types and Features of Parallel Slide Gate Valves   Parallel slide gate valves are available in single-gate and double-gate configurations. ● Gates may include flow-through holes or be solid. Gates with flow-through holes match the seat inner diameter, facilitating cleaning and drainage of the pipeline. ● Sealing can be configured at the inlet end, outlet end, or at both ends, depending on application requirements.   This design ensures flexibility in sealing arrangements while maintaining reliable oper...