The Van bướm are quarter-turn valves used for throttling and flow control. Their simple design makes them popular choices due to their cost efficiency compared to ball valves of similar size and shape.
Space saving products like these are ideal for systems with limited space. They come in various materials and styles to fit a range of applications.
Disc Seal
The disc seal, or sealing ring, on a backflow valve is an integral component that prevents water from flowing backward into your home’s water supply. It is located at the bottom of the valve body.
The ring, usually constructed out of softer materials like PTFE or rubber, sits between the stem and disc to restrict flow in the valve and prevent solids from clogging it.
Lining butterfly valves is an option that protects their internal surfaces from caustic or corrosive chemicals and improves their flow coefficient. Lining butterfly valves is often employed in applications requiring fire resistance, typically available in high-pressure classes.
Butterfly valve designs come in a wide variety of variations, such as seat design, body material and offset design that can significantly affect their flow characteristics, sealing capabilities and operating torque characteristics.
Body
The valve body must be constructed of a robust, rigid material to safeguard its internal components and to withstand high fluid pressures.
The Van một chiều typically have rectangular bodies. While they can be manufactured from various materials, the flange dimension must be sufficient to ensure compatibility with the type of piping being used.
Double-flanged or wafer valves feature bolts on both ends that connect to pipe flanges, while lugged types feature threaded lugs around the circumference of the body that allow one flange to be removed while another remains active (Figure 4.63).
Butterfly valves made of stainless steel are ideal for handling aggressive fluids, high pressures and temperatures. They come in several grades such as austenitic or duplex stainless steels; carbon steel offers a cost-effective alternative but cannot be used for corrosive applications.
Stem
The stem on a Backflow valve is the part that attaches the disc to its external operating mechanism. It is secured in place with bushings and O-rings in order to prevent fluid leakage.
There are two basic stem designs: zero offset (concentric) and eccentric. Concentric designs place the stem centered inside of the disc, while eccentric ones place it behind its centerline.
This design prevents blockages that could disrupt powder mix flow and product integrity in spice and seasoning manufacturing processes.
A butterfly valve consists of four main parts: the body, disk, stem and seat. These parts can be made from various materials to meet specific application demands but must be tough and durable for protection against fluid pressures inside.
Seat
The seat on a Backflow valve is the area that seals against bidirectional pressure differentials to prevent backflow. Usually made of resilient material with an additional metal-to-metal seal, this seat plays an essential role in keeping out debris and insects. You can also get the Đồng hồ nước.
When selecting a seat for any service, there are various types available. The most popular is the resilient-seated seat which wraps around both faces of the valve.
This type of seat serves as a gasket and does not need replacing, however it must be installed correctly for it to achieve high pressure ratings and maximum seating/unseating torque.
Other types of seats include laminated and solid metal designs. They can be constructed from various materials such as steel, aluminum, brass, stainless steel and bronze.
