1. Structural Definition and Connection Methods
Lug Features
Lugs with threaded holes extend from both sides of the valve body. Short bolts secure the pipe on one side independently, eliminating the need to penetrate the valve body.
Threaded Hole Design: Bolts screw into the lug's threaded holes to secure the pipe (the mainstream design), avoiding compression on the valve body's sealing surface.
Through-Hole Design (a minority option): Bolts must be inserted through the lug, resulting in less stable operation. This should be carefully considered when purchasing.
Differences from flange butterfly valves
| Comparison Item | Full lug butterfly valve | Flange butterfly valve |
|---|---|---|
| Bolt layout | Short bolts independently fix the pipe on one side | Long bolts pass through valve and pipe flanges |
| Sealing surface under pressure | No bolt extrusion, extending the sealing life | Bolt pressure may cause seal deformation |
2. Advantages
Convenient Maintenance
The valve will not fall out when disassembling a single-side pipe, making it suitable for locations requiring frequent maintenance, such as pipeline ends and reactor outlets.
Shorter bolt length reduces the risk of leaks caused by creep.
Seal Protection
Bolt pressure acts only on the lugs, protecting the valve seat from mechanical stress.
Space Adaptability
The compact design makes it suitable for installation in space-constrained locations (such as densely populated areas).
3. Performance Parameters and Limitations
| Terms | Features |
|---|---|
| Voltage rating | PN6-PN16(Medium pressure) |
| Applicable temperature | -20℃～200℃(Depends on sealing material) |
| Applicable media | Water, steam, gas and weak corrosive fluids |
| Taboo working conditions | High pressure (>PN16), media containing hard particles |
