SEALING
PART NAME
1 Body 2 Disc( Obturator) 3 Seal Clamping Ring
4 Stainless-steel Seat Ring
5 Gasket( Sealing Ring)
Figure 2. Butterfly valve with sealing to a stainless-steel seat ring
difficult to activate the valve in emergencies and poses a risk to system safety.
New gasket structure
A new gasket design( patent pending) from SAMSUN Makina Sanayi greatly reduces this adhesion effect thanks to its unique geometric design. By sharpening the gasket tip and optimising the contact surface, the adhesion between the gasket and the seating surface remains minimal, even if the valve stays closed for a long time, and the initial operating torque is reduced. As a result, reliable activation is ensured, and the valve can function without operator intervention- especially important for emergency valves. The new gasket design is not limited to conventional seated valves; it can also be used effectively on butterfly valves without seating surfaces, e. g., enamel-coated valves.
Figure 3. Gasket cross-section showing that the contact area is large.
In non-seated valves, the seal’ s performance depends directly on the inner lining of the valve body. The new gasket structure is highly compatible with corrosion-resistant coatings such as epoxy, PTFE, enamel, etc. and successfully fulfils the sealing task. Thanks to its tolerance for variations in surface finishes, the gasket provides reliable sealing and a long service life without causing wear on the gasket surfaces. These features make the new gasket design an ideal solution for valves with internal coatings and untreated seating surfaces, providing cost advantages and ease of production with smaller actuating systems in a wide range of applications.
EN 1074 standard
The EN 1074 standard defines the performance and reliability criteria for valves, particularly those used in water supply systems. According to this standard, the sealing performance of butterfly valves is tested based on a specific number of opening and closing cycles. These tests are generally conducted to demonstrate that the valve and gasket system is long-lasting and reliable. The new SAMSUN Makina Sanayi gasket has a lifespan of at least twice the number of opening and closing cycles specified in the EN 1074 standard. This is a significant improvement in gasket durability and performance, ensuring it maintains its sealing properties even under long-term use. This superior performance enhances system reliability, especially in critical applications such as emergency valves, and reduces maintenance costs.
Eco-design principles
Developed in line with eco-design principles, the invention reduces the mechanical load on components that transmit torque in the valve due to the low torque requirement. This reduces the risk of material fatigue and structural deformation in related parts, enabling the use of designs with thinner sections and less raw material use. As a result, the number of resources used in production decreases, energy efficiency increases, and an environmentally friendly, sustainable product structure is achieved. These benefits minimise the product’ s environmental impact while also providing significant cost advantages.
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Reliable activation is ensured, and the valve can function without operator intervention- especially important for emergency valves.”
How the gasket works
In the double eccentricity butterfly valve design developed within the scope of the invention, a double eccentric valve structure is adopted. This structure is formed by offsetting the disc axis from both the horizontal and vertical axes to a certain extent. Thus, the disc does not contact the seal through friction while rotating, but only at the point of closure. Thanks to this design, frictional forces are minimised, and low torque openingclosing is achieved. The clamping flange, used to fix and adjust the gasket’ s tightness, ensures the seal remains stable by evenly distributing the force on the gasket. This reduces gasket deformation and prolongs the seal life. The sealing surface on the valve body is the area where the gasket seats and sealing are achieved. The machining precision of this surface and its compatibility with the gasket are critical to the overall system’ s performance. Within the scope of the invention, the contact angle and force between this surface and the gasket are optimised to provide effective sealing with lower torque.
28 Valve World December 2025 www. valve-world. net