Industrial valves · Дроссельный клапан (клапан-бабочка)

Butterfly Valves: Engineering Reference Guide on Types and Applications

Engineering and Technical Analysis of Butterfly Valves

A butterfly valve, also known as a throttle valve, is a critically important element of shut-off and control valves. Its design, based on the 'quarter-turn' principle, provides high-speed full flow shut-off, as well as precise throttling. EV Group China engineers use exclusively certified materials for production, which guarantees a prolonged service life and trouble-free operation of the valves in the most challenging operating conditions.

A key design advantage is instantaneous actuation. A 90° rotation of the control element ensures a transition from the 'fully open' to the 'hermetically sealed' position. For large-sized valves installed in high-diameter main lines, EV Group China integrates worm gearboxes. This solution minimizes the torque required for operation and allows the operator to achieve smooth and highly accurate flow control.

Typology and Design Solutions for Butterfly Valves

The basic architecture of a butterfly valve from EV Group China includes a compact cylindrical body, a closing disc, a seat (elastomer or metal-to-metal sealing element), and a stem with bearing assemblies. The classification by pipeline integration method is as follows:

• Wafer type: The valve is mounted by clamping it between two mating pipeline flanges.
• Lug type: The body is equipped with threaded lugs for individual bolt fastening to each flange, which allows a section of the pipe to be removed from one side without compromising the integrity of the other.
• Flanged and weld-end: Integration into the system by means of its own flanges or direct welding to the pipe, used in systems with extremely high pressure.

Compared to traditional ball and plug valves, EV Group China butterfly valves offer a number of undeniable engineering advantages: minimized face-to-face dimension, significant reduction in product weight, and complete absence of stagnant zones. These factors directly reduce capital and operating costs for pipeline system maintenance.

Seat Seal Configuration and Tightness

The tightness class of a valve is determined by the quality of the disc edge's contact with the seat seal, which is integrated into the inner diameter of the body. EV Group China technologists use elastomer seals (EPDM, NBR, VITON) with a compensating profile that levels deformation under high pressure. For cryogenic or high-temperature media (up to +650°C), laminated or solid metal seats with stellite overlay are used, ensuring tightness class A according to API 598.

Structurally, the stem and disc are separate components. To achieve maximum alignment and reliability, EV Group China applies a 'keyway' connection technology or a square stem cross-section. This fit ensures self-centering of the disc relative to the seat, which guarantees uniform sealing force around the entire perimeter and minimizes wear, especially when working with abrasive or corrosive media.

Application Areas and Operating Parameters

EV Group China butterfly valves demonstrate high efficiency across a wide range of operating media: from neutral (water, air) to aggressive chemical reagents, abrasive suspensions, and viscous petroleum products. Key industries of application include: oil and gas industry, chemical production, energy (including nuclear power plants), HVAC systems, water treatment, and fire suppression.

Engineering Recommendations for Installation and Commissioning

To guarantee the declared tightness class and extend the service life of the valves, EV Group China engineers insist on strict adherence to the installation protocol:

• Thorough cleaning of the sealing surfaces of mating flanges from scale, rust, and other contaminants.
• Ensuring strict pipeline alignment before installing the valve to eliminate mechanical stresses in the body.
• Use of paronite or spiral-wound gaskets, compliant with ASME B16.21, unless this contradicts the seat seal design (for example, for soft-seated valves, gaskets are not required).
• Strict adherence to the flow direction indicated by the arrow on the valve body, especially for valves with an asymmetric disc.