A Concise Guide to Soft-Seated Butterfly Valve

A soft-seated butterfly valve is a common pipeline control device widely used across various industries, such as oil and gas, chemical processing, metallurgy, municipal construction, water treatment, food processing, and pharmaceuticals. As a critical component in pipeline systems, it is primarily utilized for opening and closing fluid flow and regulating flow rates. Compared to other types of valves, the soft-seated butterfly valve has become the preferred choice in many applications due to its simple structure, flexible operation, and excellent sealing performance.
Sealing Structure of Soft-Seated Butterfly Valves

The sealing structure is one of the core features of a soft-seated butterfly valve, directly impacting its performance and range of applications. Based on the sealing material, the soft-seated butterfly valve can be categorized into two types.
1. Non-Metal to Non-Metal

This type of sealing pair consists of two sides made of non-metallic soft materials, such as rubber to rubber or PTFE to PTFE. These seals offer excellent sealing performance and are especially suitable for low-temperature, low-pressure, and non-abrasive environments.
2. Metal to Non-Metal

In this configuration, one side of the sealing pair is made of a hard metal material, while the other side is made of a soft non-metallic material, such as steel to rubber or steel to PTFE. This structure combines the mechanical strength of metal with the flexibility of non-metallic materials, providing reliable sealing at lower temperatures and pressures, but it is not suitable for high-temperature or high-abrasion conditions.
Design Features of Soft-Seated Butterfly Valves

Soft-seated butterfly valves are designed with both ease of operation and sealing reliability in mind. The key design features include the following aspects.