Electric Butterfly Valve

Lightweight and Compact Construction
A thin metallic strip acts as a flow-control mechanism for butterfly valves. The disc connects to the actuator through a lightweight stem. As a result, the space required for housing the disc reduces. The bodies of butterfly valves are compact and occupy a smaller space than other valve types. The valves can fit in pipelines that are in confined spaces.
The cost of manufacturing valves depends on the quantity of materials required. Butterfly valves are cheap since they do not consume a lot of material. Their compact construction means that the valves do not get bulkier as the diameters of the water distribution and treatment systems increase.

Low-Pressure Drop and High-Pressure Recovery Factor
Water distribution systems require continuous pumping to bridge consumer demands. When a pressure drop exists in the system, the energy requirement for pumps spikes. Valves induce pressure drops across pipe sections and can strain pumps. The disc of the butterfly valve is always present in the flow. However, its lightweight construction ensures that the pressure drop across the valve is minimal. The disc has a high-pressure recovery factor and responds fast to changes in pipe pressure conditions.
The ability of butterfly valves to maintain low-pressure drops ensures that the energy consumption for pumping water across the complex municipal water systems is low. That way, the cost of operating the pipelines is low.

Ease of Operation and Actuation
Using a thin metallic strip as the flow regulation mechanism simplifies the operation and actuation of butterfly valves. The disc requires small amounts of force to combat the frictional resistance of the service fluid. The torque required to initiate the quarter-turn of the valve is equally low.

Low Maintenance Requirements
Butterfly valves have few internal components, and simple constructions ensure that few parts interfere, resulting in fewer breakdowns. The valves do not have pockets that trap debris and dirt in water and wastewater.
With fewer breakdowns and maintenance interventions, the valves can operate through several cycles, a desirable quality for large-scale water distribution and wastewater collection.

Quick and Efficient Sealing
Butterfly valves respond quickly to control signals. They seal efficiently against the service media. Municipal water distribution applications require the highest levels of precision to guarantee the purity and potability of water. In wastewater collection and treatment systems, the valves prevent leakages that may affect the quality of processes.

Electric Actuator
A valve actuator is the mechanism for opening and closing a valve. Manually operated valves require someone in attendance to adjust them using a direct or geared mechanism attached to the valve stem.

Valve Body
Made from a tough and rigid material, the valve body houses and protects the disc and other internal components of the butterfly valve. It links the valve to the piping system and to the external operating mechanism that controls the disc.

Disc
The disc permits, regulates, and stops the flow of the fluid in the pipeline. Flow is controlled by the rotary motion of the disc. The discharge flow rate depends on the degree of disc opening.
When the disc is perpendicular to the flow's cross-sectional area, the fluid is fully obstructed from flowing out of the valve. Otherwise, the fluid is permitted to flow through the space between the seat and the disc. It takes a 90° rotation from the closed position of the disc to allow full opening or closing of the valve. Flow is throttled when the disc is rotated less than 90°.

Stem
The stem is a shaft that connects the disc to the external operating mechanism. It is sealed by O-rings and bushings to prevent fluid leakage. The stem can be made from a one-piece shaft or two-piece (split-stem) shaft. The placement of the stem axis and its connection to the disc depends on the type of butterfly valve.

Seat or Sealing Ring
The valve seat for basic concentric butterfly valves is a ring that provides sealing between the disc edge and the valve body when it is in a closed position. Its sealing action is necessary to avoid leakage of any fluid to the discharge of the butterfly valve. Since the disc slides on the surface of the seat during valve opening, it must be made from a material with a low coefficient of friction.
The butterfly valve seat can be made a soft seat or a metal seat. The material of the seat limits the temperature and pressure rating of the butterfly valve. Soft seats, which are made from plastic and elastomeric materials, are limited to lower temperature applications because they deform at elevated temperatures. Metal sealing rings are capable of performing at higher temperatures and have a longer seal ring life but are difficult to completely seal.

Operating Mechanism
The external operating mechanism of a butterfly valve controls the fluid flow across the valve. It may be operated by manual rotation of the stem or by automatic actuation.
Manual operation of butterfly valves involves the application of torque to the lever or handwheel attached to the stem. Levers can set the valve into a closed, fully-opened, or partially-opened position. Larger butterfly valves are equipped with handwheels and gearboxes to increase torque and to aid in the opening and closing of the valve.
Automatic actuation may be used to control the butterfly valve situated in harsh environments and remote locations. It makes the opening and closing of butterfly valves faster, especially for larger valves requiring larger amounts of torque. The types of actuations used in butterfly valves to turn the valve stem are electromechanical actuation, (which uses an electric-powered motor), pneumatic actuation (which moves a piston or a diaphragm with compressed air), and hydraulic actuation, (which moves a piston or a diaphragm with hydraulic pressure).

Triple Offset
Tripled offset has three eccentrics each of which is located differently in the valve. The eccentrics are placed in an offset position to form an offset conical profile creating a right angle cone.

Bushing or Bearing
The quality and type of bushing determines the longevity of a butterfly valve. The best bushings are resistant to corrosion and wear and used for precision control, current limiting, and switching of chemicals, petrochemicals, chlorine, paper production, and electroplating. Bushings are made from a variety of materials with many types being self lubricating for enhanced performance of the butterfly valve.