The butterfly-type buffered check valve consists of a valve disc, a buffer device, and a micro-adjustment valve. It utilizes stainless steel sealing surface welding technology and a triple eccentric sealing structure. Available in diameters of 40-1400mm, it can handle media including water, oil, and wastewater, and is suitable for temperatures up to 200℃. Equipped with a buffer cylinder, the valve achieves slow valve closure by controlling the hydraulic oil flow rate through the regulating valve, thus reducing water hammer effects. Primarily used in industrial water supply systems, wastewater treatment plants, and pressure auxiliary systems, it features low fluid resistance and reliable sealing.
Structural Features
Valve Body and Butterfly Plate: The valve body has a compact structure and is usually cast, made of materials such as cast iron, cast steel, and stainless steel. The butterfly plate is disc-shaped and installed in the valve body, rotating around a pin inside the valve seat to open and close the valve.
Sealing Structure: Soft seals are commonly used, such as sealing rings made of nitrile rubber, installed on the butterfly plate or valve body, tightly fitting against the valve seat to achieve a seal. Some butterfly-type buffer check valves employ a triple-eccentric or double-eccentric design, allowing the butterfly plate to better fit against the valve seat when closed, improving sealing performance and reducing leakage.
Buffer Device: Commonly used devices include hydraulic cylinders or springs. Hydraulic cylinders regulate the closing speed of the butterfly plate by controlling the flow of hydraulic fluid; springs utilize their elastic potential energy to provide a buffering force during the butterfly plate's closing process, slowing down the closing speed and preventing water hammer.
Working Principle
When the medium flows in the specified direction, the pressure of the medium acts on the butterfly plate, overcoming its own weight and friction, pushing the butterfly plate to rotate around the pin and open, allowing the medium to pass smoothly through the valve. When the medium flows in the opposite direction, the butterfly plate rotates in the closing direction under its own weight and the reverse pressure of the medium. At this time, the buffer device begins to function, controlling the closing speed of the butterfly plate, first quickly closing most of the passage, and then slowly closing the remaining part, thereby effectively eliminating the generation of destructive water hammer peaks.
Performance Characteristics
Low Fluid Resistance: The streamlined internal passage of the valve minimizes the obstruction to medium flow when the butterfly plate is open. Compared with other types of check valves, such as swing check valves, it has lower fluid resistance under the same operating conditions, reducing energy consumption.
Good Sealing Performance: Utilizing high-quality rubber sealing rings or an eccentric sealing structure, it effectively ensures the valve's sealing performance in the closed state, preventing medium leakage.
Significant Buffering Effect: Through the action of the buffer device, water hammer caused by sudden closure can be avoided, protecting the pipeline system and related equipment from damage caused by water hammer impact.
Sensitive Operation: The butterfly plate opens and closes based on the flow of the medium itself, requiring no external power source. Its interlocking action with pumps and other equipment is rapid, responding promptly to changes in medium flow direction.
Application Areas
Industrial Water Supply: Used in industrial production for water supply pipeline systems to prevent backflow and protect pumps and other water treatment equipment. Widely used in cooling water circulation systems and industrial water supply systems in industries such as chemical, steel, and power.
Sewage Treatment: Installed at the pump outlet of sewage treatment plants to prevent sewage backflow from damaging pumps and pipelines, ensuring the normal operation of the sewage treatment process.
Building Water Supply and Drainage: Can be used in water supply and drainage systems of high-rise residential and commercial buildings, especially in pressurized water supply systems, effectively preventing water hammer and protecting the safety of pipelines and equipment.
Butterfly Type Buffered Check Valve Drawning
