1. Bidirectional flow Hard-seal Rotary Ball Valve Can be cut off under the positive pressure and be cutt off too under the negative pressure when negative pressure is stronger than the positive pressure;

 2. Bidirectional flow Hard-seal Rotary Ball Valve was developed based on the ball valve's advantage and butterfly valve's construction performance which have the ball valve's outstanding features. Dual sealing, adjustable,long service time as well as butterfly valve's characters. Small volume, light weight.

 Bidirectional flow Hard-seal Rotary Ball Valve essence is butterfly type eccentric half ball valve.
 Bidirectional flow Hard-seal Rotary Ball Valve sealing principle combined trunnion ball valve's front seal and eccentric butterfly valve's compulsory seal so that it can be closed under the condition of high pressure and low pressure.

 3. to meet with different needs for hardness, two seal faces of the seal pair can be applied with plasma coating, vacuum protective penetration surfacing, or other advanced processes to form martensitic stainless steel, austenitic stainless steel, carbide, cermet, and artificial diamond functionally gradient materials;

 4. Self-centering and automatic wear compensation over distance;

 5. Make full use of the energy of medium inside the valve for valve closing, and add extreme high sealing pressure automatically to achieve reliable zero leakage at the seal pair;

 6. Instant closing and opening of the seal pair without friction in between. When being opened, the spool projected cross section contracts and retracts continuously, with a higher retracting speed than the contracting speed at the beginning stage of opening. When being closed, the spool projected cross section expands and advances continuously, with a higher expanding speed than the advancing speed at the beginning stage of closing and higher advancing speed than expanding speed at the final stage of closing. this valve combines the characteristics of eccentric half-ball valve, globe valve and wedge gate valve.

 7. Mainly similar to butterfly valves, it features short construction and compact size, and therefore can be made to have large bore, extra-large bore and super-large bore.

 8. this valve combines the functions and advantages of butterfly valve, semi-ball valve, gate valve and globe valve in addition to absolutely different strengths unique to it. Due to compact size, light weight, easy and convenient transportation, installation, maintenance and repair, and reliable operation, this valve becomes another major technical revolution in valve industry.