D373H-10 Cast Steel Triple Eccentric Hard Seal Butterfly Valve

Zhejiang PutianWorking principle of triple eccentric metal hard seal butterfly valve: In a typical triple eccentric metal seal butterfly valve, besides the two eccentricities of the valve stem and disc, the sealing surfaces of the disc and seat are shaped like an oblique truncated cone (this is the so-called third eccentricity of the triple eccentric design). When the triple eccentric metal hard seal butterfly valve closes, the disc is pushed forward due to the eccentricity, and no friction occurs between the disc and seat during the closing process. The disc directly presses against the seat, ensuring the valve's service life;

Additionally,Zhejiang Putian ValveSince the sealing ring of this valve (whether installed on the seat or disc) has a certain elasticity, and there is a small gap between the boss inside the elastic ring and the elastic ring itself, allowing slight displacement of the elastic ring; when the valve closes, under the action of the closing force, the elastic sealing ring can automatically move to a position with uniform force distribution; combined with slight deformation of the elastic ring, the sealing ring at the seat is evenly stressed, achieving a sealed state.

Performance changes of butterfly valves with different eccentric structures: In traditional views, butterfly valves could only be used in applications with normal temperature, low pressure, and low sealing requirements.

With the continuous development of modern technology and materials industry,Zhejiang PutianThe application range of butterfly valves has far exceeded the past, almost replacing most traditional valves, and is widely used in various industrial fields. Particularly, the triple eccentric metal seal butterfly valve has attracted significant attention.

Since the closing of the triple eccentric butterfly valve, like that of a gate valve, is achieved through torque, the greater the closing torque, the better the sealing performance of the seat. Therefore, some refer to the triple eccentric butterfly valve as a90° rotary gate valve. In factory overhauls, more and more triple eccentric butterfly valves are replacing gate valves. For this reason, some manufacturers of triple eccentric butterfly valves specifically produce triple eccentric butterfly valves with the same length as gate valves and call these triple eccentric metal seal butterfly valves triple eccentric gate valves.

Zhejiang PutianAs the number of disc eccentricities increases, the thickness of the disc also increases, which increases the resistance of fluid flowing through the triple eccentric butterfly valve; with the increase in the number of eccentricities, the performance of the valve also changes significantly.

A comparison of four different butterfly valve structures shows that: triple eccentric butterfly valves can generate a large pressure drop and can be used as control valves; the pressure drop of fluid flowing through the valve increases with the number of eccentricities; however, compared to some non-butterfly valves, the pressure drop of triple eccentric butterfly valves is relatively small. As the number of eccentricities changes, the sealing performance of the seat also changes, with triple eccentric butterfly valves having excellent seat sealing performance. As the number of eccentricities increases, the torque required to open and close the valve decreases, so the torque required for triple eccentric butterfly valves is much lower than that of other types of butterfly valves.

With changes in the number of eccentricities, the temperature and pressure rating range and applicable temperature range of butterfly valves also change significantly. The applicable temperature and pressure rating range of triple eccentric butterfly valves are superior to those of other types of butterfly valves.

Advantages of triple eccentric butterfly valves: Excellent shut-off performance. The triple eccentric metal seal butterfly valve uses torque to shut off the valve, resulting in excellent sealing performance at the seat, hence it is sometimes called a zero-leakage valve. Solid particles or dirt in the medium have no significant impact on the shut-off performance of the triple eccentric metal seal butterfly valve because when the valve is close to closing, the medium flow velocity is high, preventing dirt from accumulating at the seat.