Wafer Butterfly Valve

1. What is Wafer Butterfly Valve?

A Wafer Butterfly Valve serves as an essential flow management component within modern industrial piping networks. This specific design features a compact, circular body intended to be clamped between pipe flanges using long bolts, which provides a significantly shorter face-to-face dimension compared to traditional gate or globe designs. By utilizing a central disc that rotates around a stem, the equipment achieves rapid isolation and modulation of fluid media across various industrial sectors.

This equipment integrates a high-precision rotary mechanism with versatile actuation options, allowing it to function as a cornerstone of automation in production lines. Unlike bulkier flanged alternatives, the wafer-style architecture is characterized by its lightweight nature and ease of installation. It is engineered to meet rigorous international standards, including GB, ANSI, JIS, and DIN, ensuring compatibility with diverse global infrastructure. Whether configured for manual operation or managed remotely through sophisticated pneumatic or electric control systems, this device offers a reliable solution for handling everything from pure water to highly aggressive chemical substances.

2. How this Rotary Device Works?

The operational mechanism of this clamped flow controller relies on the rotational synergy between the actuator and the internal disc assembly. When the driving force—typically compressed air for pneumatic units or electrical signals for motorized versions—is applied, the stem transfers torque to the disc, causing it to pivot within the flow path.

The core operational stages are as follows:

1. Opening Phase: As the actuator rotates the stem, the disc turns from a position perpendicular to the flow to one parallel to it. In this state, the media can pass through the body with minimal obstruction. The streamlined disc profile is designed to maintain high flow coefficients (Cv) while minimizing pressure drop across the system.
2. Closing and Sealing Phase: A ninety-degree rotation in the opposite direction brings the disc edge into contact with the seat. In center-lined plastic units, an interference fit between the polymer disc and the elastic seat ensures a bubble-tight seal. In high-performance metal versions, a triple eccentric design is often employed. This configuration offsets the stem in three dimensions, allowing the disc to wedge into the seat only at the final moment of closure, which eliminates friction during the travel and significantly extends the life of the sealing surfaces.
3. Actuation and Control: Many models utilize the AT or GT series pneumatic actuators. These units convert linear piston motion into rotational torque through a rack-and-pinion system. For precise modulation, accessories such as intelligent positioners are added to adjust the disc angle according to real-time process requirements.

3. Types of Wafer-style Units

3.1 Material and Body Classification

The choice of material is determined by the chemical properties and temperature of the handled media:

• Plastic Series: Constructed from advanced polymers like UPVC, CPVC, PPH, and PVDF. The UPVC models are ideal for water treatment at ambient temperatures, while PVDF units offer extreme chemical resistance and can operate in temperatures ranging from -40 to 140 degrees Celsius. These are preferred for semiconductor and lithium battery manufacturing due to their ability to prevent metal ion contamination.
• Metal Series: Manufactured using carbon steel (WCB) or stainless steel alloys such as 304, 316, and 316L. These metal units are designed for high-pressure environments (up to PN25 or higher) and can withstand much higher thermal stresses than plastic counterparts.
• Lined Series: For applications requiring both mechanical strength and chemical inertness, fluorine-lined (PTFE or PFA) models are used. The metal body provides the structural integrity, while the inner lining protects all wetted parts from corrosive attack.

3.2 Structural and Sealing Variations

• Center-lined Soft Seal: Features a symmetrical disc and a resilient seat (EPDM, FPM, or PTFE), suitable for general purpose water and chemical services.
• Triple Eccentric Hard Seal: Utilizes a metal-to-metal sealing mechanism. This design is specifically engineered for high-temperature and high-pressure steam or oil applications where soft seals would fail.

4. Core Advantages of the Clamped System

The compact design of the wafer-style unit offers several distinct benefits for industrial operators:

• Efficient Footprint: The short face-to-face length saves valuable space in complex piping manifolds and reduces the overall weight of the piping system, lowering structural support costs.
• High Sealing Integrity: Precision-engineered seats provide bi-directional sealing capabilities. The use of high-grade fluoropolymers ensures that the device remains leak-proof even when handling aggressive acids or alkalis.
• Standardized Mounting: Most units feature an ISO 5211 top flange, allowing for the seamless exchange of actuators without modifying the valve body.

5. Industrial Applications

Due to their versatility and rapid response times, these devices are integrated into a wide array of critical industrial processes:

1. Chemical and Pharmaceutical: Used for the precise control of acidic and alkaline solutions. PVDF and CPVC models are particularly effective in resisting the corrosive effects of complex chemical mixtures.
2. Lithium Battery and Semiconductor: In these high-purity environments, plastic wafer units handle ultrapure water and electrolytes, ensuring that no metallic contaminants are introduced into the production line.
3. Water Treatment and Desalination: UPVC and PPH equipment is widely deployed in sewage treatment and desalination plants due to its excellent resistance to chlorine and cost-effectiveness.
4. Metallurgy and Power: Metal triple eccentric models are used in cooling water systems and steam lines where high temperatures and pressures are standard, providing reliable isolation under harsh conditions.