Categories of ball valve can be classified in to floating ball valve, trunion mounted ball valve, elastic ball valve (also called as track ball valve), V ball valve, three-way ball valve.

 

1. Floating ball valve

Characteristics of floating ball valve:

(1) showing position of on-off;

(2) lock device;

(3) protective structure on stem;

(4) anti-static device;

(5) fireproof structure;

(6) unique base seal structure;

(7) non-leakage structure in middle flange.

 

Body of floating ball valve can be made of carbon steel, stainless steel, low temperature and sulfur materials.

 

Body of floating ball valve is floating. Under the pressure of medium, the body moves and press to sealing face of exit, sealing exit. Floating ball valve has simple structure and good sealing. However, body transmits whole of loading to the seal ring at exit. For that, the materials of sealing ring must be considered whether can withstand loading or not. High pressure may cause shifting of body. Floating ball valve can be used under low pressure.

 

2. Trunnion mounted ball valve

Body of trunnion mounted ball valve is fixed. It cannot move under pressure. Trunnion mounted ball valve is equipped with floating base. Under pressure of medium, base deviates and presses sealing ring to ball, ensuring seal. Generally, upper axle and down axle of body have shaft. Trunnion mounted ball valve has small torque, applicable for high pressure, large caliber pipelines.

 

To reduce torque and improve seal, oil seal ball valve has come out. Special lubricant is injected between sealing faces, forming a layer of oil slick to improve seal and reduce torque. Oil seal ball valve is more applicable for high pressure pipelines.

 

3. Elastic ball valve (track ball valve)     

Body of elastic ball valve has elasticity. Body and seal ring of base is made of metal, having high seal specific pressure. Utilizing pressure of medium cannot realize seal. For that, external force must be imposed on body. The valve is suitable for high pressure and temperature medium.

 

An elastic slot exists at the bottom inside body, so body acquires elasticity. When closing channel, wedge head of stem makes body roll out and press to base for seal. Before rotate body, loosen wedge head and body snaps back into shape. There is a small gap between body and base, reducing friction of sealing face and torque.

 

4. V ball valve

V ball valve belongs to trunnion ball valve. It is also one of single base seal. V ball valve has the highest performance of regulating. Discharge characteristic is 100%. Regulating ration is 100:1. V cut and metal base has shearing. V ball valve is quite suitable for medium containing fiber, small rigid granules, etc.

 

5. Three-way ball valve

Three-way ball valve can be classified into T three-way ball valve and L three-way ball valve. Three-ball valve makes three orthogonal pipelines interconnected and cut off the third pipeline, diverting traffic and merging effect. L three-way ball valve makes two orthogonal pipelines. It can be only used to distribution. 

 

Characteristics:

(1) Using integrated structure, having less flanges, high reliability and light weight.

(2) Long service life, low resistance.