Concentric vs. Double Eccentric Butterfly Valves

Butterfly valves are a type of quarter-turn valve used for regulating and controlling the flow of fluids through a pipe. They are widely utilized in various industries due to their simple design, compact size, and ease of operation. Within the realm of butterfly valves, there are different types available, including concentric butterfly valves and double eccentric butterfly valves.

 

Butterfly valves are a type of quarter-turn valve used for regulating and controlling the flow of fluids through a pipe. They are widely utilized in various industries due to their simple design, compact size, and ease of operation. Within the realm of butterfly valves, there are different types available, including concentric butterfly valves and double eccentric butterfly valves. In this article, we will explore the differences between these two valve variants, their unique characteristics, and the benefits they offer.

 

 

What are Concentric Butterfly Valves?

A concentric butterfly valve is designed with a disc that is centered within the pipe. The valve comprises a metal disc or plate that rotates on a spindle, which allows or blocks the flow of fluids. When the disc is rotated to a perpendicular position, the valve is fully closed, and when it is parallel, the valve is fully open.

The sealing mechanism of a concentric butterfly valve involves the disc compressing the elastomer liner against the valve seat to provide tight shutoff. This design ensures low torque requirements, excellent sealing capabilities, and reliable performance. Concentric butterfly valves are commonly used in low-pressure applications, where bubble-tight shut-off is not critical, such as water treatment plants, HVAC systems, and food and beverage industries.

 

The Advantages of Concentric Butterfly Valves:

1. Cost-effective solution for low-pressure applications.

2. Easy installation and maintenance due to their simple design.

3. Lower torque requirements and quick operation.

4. Good flow control capabilities with low pressure drops.

 

What are Double Eccentric Butterfly Valves?

Double eccentric butterfly valves, also known as high-performance butterfly valves, are designed with a disc offset from the center of the pipe. This offset disc design allows the disc to move away from the seat during the opening process, minimizing mechanical interference and reducing friction. Double eccentric butterfly valves are commonly used in applications that require tight shutoff and higher operating pressures.

Unlike concentric butterfly valves, double eccentric butterfly valves use a combination of a metal disc and a soft or metal seat for sealing. The offset disc design ensures a camming action during closing, resulting in increased seating force and better sealing performance. These valves are widely employed in various industries, including oil and gas, chemical processing, power generation, and wastewater treatment.

 

The Advantages of Double Eccentric Butterfly Valves:

1. Excellent tight shutoff capabilities, suitable for critical applications.

2. Higher operating pressures and temperatures compared to concentric butterfly valves.

3. Reduced seat wear due to the offset disc design.

4. Lower torque requirements for operation.

 

Which Butterfly Valve Should You Choose?

The choice between a concentric butterfly valve and a double eccentric butterfly valve depends on your specific application requirements. If you are operating in a low-pressure environment where cost-effectiveness and easy installation are crucial, a concentric butterfly valve may be the ideal choice for you. On the other hand, if you require excellent sealing capabilities, higher operating pressures, and tight shutoff, a double eccentric butterfly valve would be a suitable option.

As a leading double eccentric butterfly valve supplier, we provide high-quality valves that are designed to meet the demanding needs of various industries. Our valves offer reliable performance, exceptional durability, and efficient flow control. To learn more about our products or to discuss your specific requirements, please do not hesitate to contact us. Our team of experts will be delighted to assist you.