What is a butterfly Valve ?.
A butterfly valve is a valve that shuts off or regulates fluid flow. The locking mechanism is a rotating disc.
It has the same function as a ball valve and can be shut off quickly. Butterfly valves are generally preferred because they cost less, are lighter, and require less support than other valve designs.
The disc is placed in the center of the tube. A rod extends through the disc to the actuator on the outside of the valve.
Turning the actuator rotates the disk either parallel or perpendicular to the flow. In contrast to ball valves, discs always have flow, so they experience a pressure drop even when open.
A butterfly valve is a type of valve called a quarter-turn valve. During operation, the valve fully opens or closes after a quarter turn of the disc. A "butterfly" is a metal disk attached to a pole. When the valve closes, the disc rotates to completely block the passage. When the valve is fully open, the disc rotates a quarter of a turn, allowing fluid to pass virtually unhindered.
You can also restrict the flow by gradually opening the valve.
There are many different types of butterfly valves, each suitable for different pressures and applications. Zero offset butterfly valves utilize the flexibility of rubber and have the lowest pressure ratings.
High performance double offset butterfly valves are used in slightly higher pressure systems and are offset from the disc seat and body seal centerline (offset 1) and from the bore centerline (offset 2). This creates a camming action that lifts the seat off the seal during operation, resulting in less friction and less tendency to wear than a zero-offset design.
The best valve for high pressure systems is the triple offset butterfly valve. In this valve, the contact axis of the disc seat is offset, virtually eliminating sliding contact between the disc and the seat. In triple eccentric valves, the seat is made of metal and can be machined to create a bubble-free seal when in contact with the disc.
Concentric Butterfly Valve – This type of valve has a resilient rubber seat with a metal washer. Double eccentric butterfly valve (high performance butterfly valve or double eccentric butterfly valve) – Different materials are used for the seat and disc. Triple Offset Butterfly Valve (Triple Offset Butterfly Valve) - The seat is made of laminated metal or solid metal.
Butterfly valve with intermediate flange design edit Wafer-style butterfly valves are designed to maintain a seal against pressure differentials in both directions to prevent backflow in systems designed for unidirectional flow.
This is achieved through hermeticity. d. H. Precision machined gaskets, O-rings, and flat valve faces on the upstream and downstream sides of the valve. The disadvantage is that wafer butterfly valves have a narrow flow control range.
The pressure drop across the wafer butterfly valve can be even higher. By design, wafer butterfly valves are prone to clogging.
Butterfly valve with tab design edit Lug style valves have threaded inserts on both sides of the valve body.
This allows you to attach it to your system using two sets of screws and no nuts. The valve is mounted between two flanges using a separate set of screws on each flange.
This design allows two sides of the piping system to be separated without affecting the other side. Tab-type butterfly valves used in dead-end service typically have lower pressure ratings. For example, a tab butterfly valve installed between two flanges has a pressure rating of 1,000 kPa (150 psi). The pressure rating for the same flange-mounted valve in dead-end service is 520 kPa (75 psi).
butterfly valves are highly resistant to chemicals and solvents and can withstand temperatures of up to 200°C, making them a versatile solution.
Butterfly valves are used in the pharmaceutical, chemical, and food industries to shut off the flow of products (solid, liquid, or gas) in a process
Valves used in these industries are typically manufactured according to cGMP (Current Good Manufacturing Practice) guidelines.
In many industries, especially the petroleum industry, butterfly valves are commonly used to replace ball valves due to their lower cost and easier installation. However, pipelines with butterfly valves cannot be "pigged" for cleaning .
Butterfly valves have been used since his late 18th century. James Watt used butterfly valves in his prototype steam engine.
Advances in material manufacturing and technology have made butterfly valves smaller and able to withstand more extreme temperatures. After World War II, the use of synthetic rubber for sealing elements led to the use of butterfly valves in many other industries.[4] In 1969, James E. Hemphill patented his butterfly valve improvement, which reduces the hydrodynamic torque required to change the valve's output.
No comments:
Post a Comment