Sleeve Type Soft Sealing Plug Valves

Specification

Soft Sealing Bronze Plug Valves

I. Product Overview

Soft-seated bronze plug valve is an industrial valve designed for fluid diversion or shut-off. It is primarily used in sectors such as chemical processing, petroleum, natural gas, pharmaceuticals, food and beverage, and water treatment—specifically in applications involving corrosive, highly toxic, or hazardous media, or where stringent sealing and hygienic standards are required. The valve body can be constructed from carbon steel, alloy steel, or stainless steel, while the sleeve is made from self-lubricating materials—such as PTFE (F4) or FEP (F46)—to accommodate various media characteristics and temperature ranges (from -196°C to 300°C).
The valve operates by rotating a cylindrical plug to open or close the flow passage. Configurations include straight-through (for shut-off) and three-way or four-way (for fluid diversion) designs. It utilizes a dual-groove sealing ring combined with a reverse-lip seal design; a soft-sealing diaphragm is used to adjust the specific sealing pressure, ensuring dynamic sealing and zero leakage, even under bidirectional flow conditions. The structure is fire-safe and anti-static, supports in-line maintenance, and allows for installation in any orientation. It is well-suited for highly erosive gas-solid or liquid-solid media (e.g., in PVC or urea production). The valve offers rapid actuation and low fluid resistance [7]. Soft-seated plug valves can be operated manually, pneumatically, or electrically, and are available with various connection types, including quick-connect, flanged, and threaded ends. For hygienic applications, the design features a "dead-zone-free" flow path that complies with FDA and cGMP standards.

II. Core Technical Parameters

A. The sleeve can be made from self-lubricating materials—such as PTFE (F4), FEP (F46), PVDF, PP, PO, or PE—selected based on the operating temperature and the specific medium. These materials provide excellent lubrication, resulting in a low coefficient of friction between the sealing surfaces throughout operation, ensuring smooth movement of the plug and an extended service life.
B. The valve body features a specific window design at the inlet and outlet, paired with a dual-groove sealing ring. As the plug rotates, the specific sealing pressure between the mating surfaces changes dynamically; upon reaching the fully open or fully closed position, sufficient sealing pressure is generated to achieve zero leakage. C. The dual-groove sealing ring secures the sleeve within the valve body, preventing displacement while accommodating minor deformations caused by temperature fluctuations. Furthermore, it facilitates effective friction between the sleeve and the plug, providing a self-cleaning action that extends the service life of the sealing surfaces.
D. The unique "reverse-lip" sealing design at the top of the plug—utilizing a combination of a soft-sealing diaphragm, a metal diaphragm, and adjustment shims—allows for the precise regulation of contact pressure between sealing surfaces. This ensures smooth plug rotation while maintaining a reliable seal at the inlet/outlet ports and the central flange connection.
E. Suitable for highly erosive gas-solid or liquid-solid media—such as those found in the production of PVC, urea, phthalic anhydride, or caustic soda—as well as for applications requiring stringent leak prevention (e.g., involving hydrogen fluoride or phosgene).
F. Supports bidirectional flow, allows for flexible installation orientation, and enables in-line maintenance for greater operational convenience.
G. Features a unique design that prevents static electricity and ensures fire safety, providing a secure operating environment.
1. Ideal for frequent operation, offering rapid and effortless opening and closing.
2. Soft-sealed plug valves exhibit low fluid resistance.
3. Simple construction, compact size, lightweight, and easy to maintain.
4. Excellent sealing performance.
5. Not restricted by installation orientation; supports flow in any direction.
6. Vibration-free with minimal noise.