Knowledge and use of butterfly valves in pipelines
Basic knowledge of butterfly valve
Butterfly valves are still very cost-effective in many applications, they cost less than other valves, their unique design and they are lighter, which means less support is required. The disc is located in the center of the pipe, and through the disc support point is the rod connected to the actuator outside the valve.
The rotary actuator causes the disks to flow parallel and vertically. Unlike ball valves, the disc is always active in the flow, no matter which direction the valve is positioned in, the butterfly valve always causes a pressure drop in the flow.
Butterfly valves come from a family of valves called quarter-turn valves. In operation, the valve can be fully opened/closed when the disc is rotated a quarter turn.
A “butterfly disc” is a metal disc mounted on a rod. When the valve is closed, turn the disc so that it completely blocks the passage. When the valve is fully open, the disc rotates a quarter turn, which allows unrestricted passage of fluid. Valves can also be gradually opened to create throttling.
Butterfly valves consist of a disc mounted on a shaft with bearings for easy rotation. With very efficient energy recovery, only the disc blocks the valve flow path. The flow is relatively high and the pressure drop across the valve is relatively low.
Butterfly valves are used to limit throttling and do not require tight shutoff. When fully open, the butterfly disc creates little turbulence and flow resistance.
Butterfly valve use:
- Fully open/close or throttle services
- frequent closing operations
- minimal fluid control
- Applications requiring a small pressure drop
Butterfly valve advantages:
- low cost and maintenance
- High capacity
- good flow control
- pressure drop
Disadvantages of butterfly valve:
- High torque at control point
- prone to cavitation at lower flow rates
- Lack of cleanliness and inability to handle slurry applications. Typically not rated as a bubble seal, cavities and leak paths around the disc rod are potential entrainments for fluids and slurries. However, some high performance butterfly valves with ASME Class VI leakage ratings are available upon request.
Butterfly valve application:
The most economical large-scale production line for chemical services, water treatment and fire protection systems. Typical sizes are 2″ to 48″, with some manufacturers offering sizes up to 96″.
Due to the valve design, smaller face-to-face size and lower weight compared to most valve types, butterfly valves are an economical choice for large diameter pipe sizes.
Butterfly valves conform to ASME port sizes and pressure ratings. Valves can be easily retrofitted regardless of the manufacturer’s production
ASME pressure ratings that most manufacturers adhere to include 150, 300 and 600# with a maximum pressure of 1500 psi.
Butterfly Valve Supplier
VALTECCN butterfly valve supplier: Butterfly valves have been produced and sold frequently for many years, and the products are sold all over the world, which has been widely recognized by users, and you can inquire at any time.