Excentrický polokulový ventil

Funkce:
1. Unique design, compact structure and versatile;
2. Large flow coefficient and wide adjustment range;
3. Valve seat and body adopt special step matching structure, effectively prevent seat jamming phenomenon;
4. Flow area is large, flow resistance is small and the valve chamber has self-cleaning function;
5. Spring automatic compensation function;
6. Reliable sealing performance and long service life:
7. Ball self-cut function;
8. Operating torque is small and can open and close easily and quickly.

Operation Type：

Převodovka, elektrický pohon, pneumatický pohon, holý vřeteno, hydraulický pohon.

1 structural features

1. Hemisphere

The hemisphere of double-eccentricity half-ball valve adopt double eccentric design, it has reliable sealing, instantaneous release, small torque, long service life, it can be used in the harsh working condition of transporting granule medium. The structure principle is that hemisphere center line has setover size with stem center line and the seat center line. When fully open, the sphere and the valve seat separated completely, and there is certain space. Radius of gyration is divided into long radius and short radius. There will be a θ angle between the tangent line on the long radius turn trajectory and the seat sealing surface. When the valve opens and closes, relative seat surface of the hemisphere will have a coming out separation and a coming in extrusion, thus to reduce the mechanical wear and abrasion between the seat and the hemisphere during operation, improving the service life.

2. The valve seat

the seat is designed floating, which reduces the processing difficulty, ensuring the coincidence between the center line of the valve seat and the sphesical centering-point of the hemisphere, thus to improve the sealing performance. There is space between the seat and the body, so when installed it can automatically find the mid-line by hemisphere locating, to ensure full contact between the seat sealing surface and the spherical surface, this solves the leakage due to the machining accuracy of error, improving the use of ball valve performance and its service life.

The seal of the seat and the body is hard seal structure, suitable for high temperature and high pressure conditions. The seat and the sealing contact surface have a small c-value, and each seal surface has a high accuracy requirement. When installed, retainer is equipped by electric impact wrench. It is not only the retainer meshing with the valve body to prevent the loose, but also the seat rubbing and rotating. It conform to the principle of mechanical vibration meshing, making the seat and the body sealed with reliability.

It is two hard seal between the seat and the body or the seat and hemisphere, so this valve can be used high temperature and high pressure conditions.

3. Other mechanical components

The whole valve adopts modular design, simple structure, good reliability, high generality. The valve stem adopts the jet structure. Diversified driving mode. The connection dimension of the valve stem, bracket and actuators conforms to ISO5211 standard, it can be directly assembled with various specifications actuators. Teh  commonly used driving mode are manual, pneumatic, hydraulic and electric, gas and liquid linkage etc, improving the performance of double eccentric half-ball valve.

2  range of application

Double-eccentricity half-ball valve is suitable for all kinds of general industry, medium such as water, sewage, waste water, steam and gas etc. If the sealing pair uses Cr-Mn-Si cemented carbide, and has the function of fireproof and explosion protection and anti-static, then it applies to the requirements of high temperature medium such as gas, coke oven gas, water gas and natural gas. If the sealing pair(hemisphere, the valve seat) and the flow channel of valve body are through tungsten carbide special craft processing, it will have advantages like high efficiency and energy saving, good abrasion resistance, reliable sealing performance, convenient operation, fast opening and closing, long service life etc, which is an ideal choice for the valve in the pipeline in the field of industrial silicon. Due to the property of instant detachment of hemisphere and the seat and instant compaction, it applies to harsh working condition of medium containing particles, it can be widely used for various pipeline control in pulverized coal, the coal pulverizing system and dust collection system in metallurgy, mineral processing and power manufacturing technique. In the process of instant detachment and instant compaction, the hemisphere and the seat squeeze and cut each other, which can remove the scaling and adhesion on the sealing surface, to ensure a reliable sealing. It is an ideal choice for valves for two phase mixed fluid medium in the technological process of transporting easy-to-precipitate scaling, crystallizing the precipitation of solution pulp and slurry ash.