SEALING
The main technical innovation of the invention is the geometric improvement to the butterfly valve gasket structure. The new gasket, with its narrower end structure, minimises initial contact when closing the valve and provides low-friction closing. This structure reduces the torque required during opening and closing. Moreover, the new gasket is also affected by the media pressure on both sides; the pressure supports the seal, making it pressure-dependent. The design of the double eccentric structure is in harmony with the gasket, eliminating the problem of high friction caused by continuous contact in conventional concentric valves. By tapering the end structure of the new gasket, the initial contact area is reduced, significantly reducing the frictional force generated during opening and closing, thus supporting the side that does not rest against the seal seating surface. The sealing gasket is supported on the opposite side when the pressure acts in one direction, thereby reducing its flexing. As a result, the opening and closing torques of the valve are reduced. In addition, over time, the gasket is prevented from sticking to the stainless-steel seating surface. Advantages of the invention: 1. Low torque requirement during opening and closing. 2. Long life and easy maintenance due to low risk of sticking. 3. Cost advantage by using low-capacity actuators and gearboxes. 4. Reduced gasket deformation extended sealing life. 5. More stable performance against high pressures with directional support structure.
6. Energy saving, equipment downsizing, environmental sustainability.
7. Compliance with eco-design principles: Less material use, less resource consumption.
8. Operator ease of use and occupational safety.
Test results
Tests show the average opening-closing torque value obtained with existing gaskets used in butterfly valves with a DN600( nominal diameter 600 mm) was 29 Nm for the PN10( nominal pressure 10 bar) version and 43 Nm for the PN16 version. In the same tests with the new gasket design, the torque value was reduced to 9 Nm for the PN10 version and 26 Nm for the PN16 version. These results show that the new design provides significant advantages in energy
The invention can be used effectively in opening, closing and flow throttling applications in process lines such as water supply systems, healthcare industry, power plants, petrochemical, etc.
efficiency and equipment selection, reducing torque requirements. As a result of the tests, it has become possible to use lower-capacity actuators in the valve system, thanks to the low opening-closing torque advantage provided by the newly designed seal structure. Accordingly, a cost advantage of approximately 23 % is achieved when a subsegment actuator is used.
“
The new design provides significant advantages in energy efficiency and equipment selection, reducing torque requirements.”
Similarly, the use of a lower capacity gearbox provides cost savings of up to 36 %. Especially in DN600 PN10 butterfly valve applications, the use of both a lower-stage gearbox and a lower-level actuator can reduce total system cost by up to 15 %. This economic benefit increases the product’ s market competitiveness and offers an important optimisation opportunity in system designs.
Conclusion and effectiveness
The developed butterfly valve seal structure is designed for use in a wide range of industrial applications. In particular, the invention can be used effectively in opening, closing and flow throttling applications in process lines such as water supply systems, healthcare industry, power plants, petrochemical, pharmaceutical and food industry, mining, maritime, machinery manufacturing industry, construction, environmental technologies, automotive, aerospace, defense industry, healthcare industry, waste water treatment plants and liquid transmission systems in the chemical industry. Thanks to the gasket design, complete sealing is ensured with low torque values during on-off operations in these systems. This feature both reduces the size of mechanical drive systems and lowers operating costs. In addition, the low torque requirement enables the use of smaller actuators in the system, reducing energy consumption and increasing system efficiency. Low Opening-Closing Torque: Thanks to the improvements made in the sealing lip and contact geometry, friction has been reduced, significantly lowering the torque required for valve opening and closing operations. Use of Smaller Actuators and Gearboxes: The reduction in torque requirement makes it possible to use actuators and gearboxes with lower capacities, resulting in space savings and reduced system costs. Lower Valve Cost: The use of smaller auxiliary equipment and the reduction in forces acting on components contribute to lowering the overall cost of the valve system. Competitive Advantage: The combination of improved performance and reduced costs makes the product more competitive in the market. Operator Ease of Use and Occupational Safety: The reduced force requirement eases the physical load on the operator, contributing to the prevention of long-term musculoskeletal disorders. Improved Test Efficiency with Quick Opening- Closing: Due to the lower torque, valves can open and close more quickly, resulting in time savings during product testing processes.
www. valve-world. net Valve World December 2025
29