GGG40 Butterfly Valve
A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid. The valve may also be opened incrementally to throttle flow.
There are different kinds of butterfly valves, each adapted for different pressures and different usage. The zero-offset butterfly valve, which uses the flexibility of rubber, has the lowest pressure rating. The high-performance double offset butterfly valve, used in slightly higher-pressure systems, is offset from the centre line of the disc seat and body seal (offset one), and the centre line of the bore (offset two). This creates a cam action during operation to lift the seat out of the seal resulting in less friction than is created in the zero offset design and decreases its tendency to wear. The valve best suited for high-pressure systems is the triple offset butterfly valve. In this valve the disc seat contact axis is offset, which acts to virtually eliminate sliding contact between disc and seat. In the case of triple offset valves the seat is made of metal so that it can be machined such as to achieve a bubble tight shut-off when in contact with the disc.
Normal pressure: PN1.0/1.6mMPa
Suitable temperature: Normal temperature -45℃-150℃
Body: Cast iron/ductile iron/wcb/carbon steel/al-bronze/CF8, ss304/CF8m, ss316
Face to face: ANSI b 16.10, API 609, bs5155 short, ISO5752(series 13), DIN3202 f16
Medium: Fresh water, sewage, sea water, air, vapor, food, medicine, oils, alkalis, salt etc.
Seat: NBR/hypalon/EPDM/neoprene/nr/wear-resistant EPDM/viton/silicon/heat-resistant EPDM/white EPDM/EPDM/PTFE
End flange: ANSI b 16.1, ASTM b 16.47, en 1092, as 2129, ISO pn10/16, JIS b2212/2213, bs 10 table d, bs 10 table e, bs4504
1. The valve is equipped with eccentric tilting tapered valve seat sealing ring for the purpose if pressing out the sealing surface has small frictional resistance. When shutting off, it cleses more and more, so this makes sealing performance reliable, Opening can ensure that the sealing.
2. The special geometric structure makes the butterfly valve free of defect that other butterfly balves are unable to be sealed will due to excessively opening, so as to gurantee good sealing of the surface.
3. The double eccentric butterfly valve structure can gurantee that the valve fundtions mormally under high prssure and overcome the shortcomings that other valve easily leak due to sest deformation when they work under high pressure.