EVA UPVC butterfly valve is a type of flow control valve, primarily used in plumbing and piping systems, especially in water and wastewater management. It features a disc-shaped element (the "butterfly") that rotates to regulate or stop the flow of fluids. UPVC (unplasticized polyvinyl chloride) makes these valves lightweight, corrosion-resistant, and suitable for various applications. 

Here's a more detailed description:

Key Features:

• Disc-shaped element: The valve's core is a disc that rotates on a stem. When the disc is aligned with the flow, the valve is open; when perpendicular, it's closed.
• UPVC Material: Provides chemical resistance, durability, and affordability.
• Versatility: Suitable for on/off and throttling applications, controlling the flow of liquids and gases.
• Compact Design: Requires less space compared to some other valve types.
• Lightweight: Facilitates easier installation and reduces stress on piping systems.
• Optional Actuators: Can be manually operated with a handle or automatically with electric or pneumatic actuators for remote operation.
• Resilient Seat: Ensures a tight seal, minimizing leakage. 

Common Applications:

• Water and Wastewater Treatment: Regulating flow in various stages of treatment.
• HVAC Systems: Controlling airflow and water circulation.
• Chemical Processing: Handling corrosive fluids.
• Food and Beverage Production: Maintaining hygiene and flow control. 
• Swimming pools and pump houses.

Benefits:

• Corrosion Resistance:

UPVC's resistance to many chemicals makes it ideal for various industrial and commercial applications. 

• Low Maintenance:

Generally low maintenance and can have long operating lives, especially with automated versions. 

• Cost-Effective:

UPVC is a relatively inexpensive material, making the valves more affordable compared to metal alternatives. 

• Easy Installation:

Lightweight and compact design simplify installation and reduce labor costs. 

• Precise Flow Control:

Well-suited for applications needing precise flow regulation. 

Actuators:

• Manual: Operated by a hand lever or gearbox.
• Electric: Controlled remotely via an electric motor.
• Pneumatic: Controlled by compressed air. 

Standards and Specifications:

• BS 5155: A British Standard specification for butterfly valves.
• API 609: An American Petroleum Institute standard.
• ASME B 16.34: A standard for valves – flange, thread, and welding ends.
• ISO 5752: An International Organization for Standardization (ISO) standard.