Double eccentric butterfly valve is further improved on the basis of single eccentric butterfly valve, which is the most widely used double eccentric butterfly valve.
Its structural characteristics are that the axis of the valve stem deviates from the center of the butterfly plate and from the center of the body. The effect of double eccentricity enables the disc to be quickly removed from the seat after the valve is opened, greatly eliminating unnecessary excessive squeezing and scratching between the disc and the seat, reducing the opening resistance, reducing wear, and improving the seat life. The scratch is greatly reduced, and at the same time, the double eccentric butterfly valve can also use metal seats, which improves the application of butterfly valves in high temperature fields.
Components and Materials
| No. | Name | Materials |
| 1 | Valve Body | Ductile Iron QT450-10 |
| 2 | Gate | Ductile Iron QT450-10 |
| 3 | Valve plate sealing ring pressure ring | 304 Stainless Steel/QT450-10 |
| 4 | Gate Sealing Ring | EPDM |
| 5 | Valve Seat | 304 Stainless Steel |
| 6 | Valve Shaft | 304 Stainless Steel |
| 7 | Bushing | Bronze |
| 8 | Sealing Ring | EPDM |
Deatiled Size of Main Parts
| Double eccentric flange butterfly valve | |||||
| Norminal Specification | Pressure | Dimension（mm) | |||
| DN | PN | D | L | D1 | H |
| 300 | 10 | 445 | 150 | 418 | |
| 16 | 460 | 150 | 428 | ||
| 350 | 10 | 505 | 175 | 462 | |
| 16 | 520 | 190 | 476 | ||
| 400 | 10 | 565 | 175 | 510 | |
| 16 | 580 | 175 | 520 | ||
| 450 | 10 | 615 | 175 | 550 | |
| 16 | 640 | 175 | 560 | ||
| 500 | 10 | 670 | 210 | 570 | |
| 16 | 715 | 210 | 620 | ||
| 600 | 10 | 780 | 210 | 650 | |
| 16 | 840 | 210 | 710 | ||
| 700 | 10 | 895 | 254 | 755 | |
| 16 | 910 | 254 | 770 | ||
| 800 | 10 | 1015 | 254 | 845 | |
| 16 | 1025 | 254 | 854 | ||
Advantages
The Double Eccentric Butterfly Valve adopts a double eccentric structure, and the integrated streamline design of the butterfly plate makes the valve highly reliable, small operating torque, short opening and closing time, and good sealing performance. It reduces and avoids maintenance during use, has a long service life, and has good use and social benefits.
The Characteristics of Double Eccentric Butterfly Valve:
1) Double eccentric structure, the butterfly plate leaves the valve seat quickly when opening, and has the function of closing and tightening when closing, the operating torque is small, (compared with no eccentricity), and the service life of the valve seat is long.
2) The sealing performance is reliable, the leakage is zero, and the opening and closing life reaches tens of thousands of times.
3) The integrated streamline design of the butterfly plate has the advantages of small flow resistance coefficient and high strength.
4) The internal and external anti-corrosion of the valve is sprayed with non-toxic electrostatic epoxy resin, the thickness can reach 0.25 mm - 0.45 mm, the anti-corrosion performance is good, the time is long, and the secondary pollution to the water is avoided.
