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SBV Fully Welded Body Ball Valves are used mainly in Gas Transmission and Distribution pipeline (Mid-stream), typical for underground and buried installation. This design is also used in many subsea applications, where maintenance activities are not foreseen. The main advantage of this type of Ball Valves are: No leaking paths through the joints. Forged Steel Body assures uniform fine grain structure and toughness free from inevitable casting defects such as porosity, abscess, sand hole, loosen, slag inclusion, crackle, gas hole.
1. Blow-out Proof Stem
For the purpose of preventing the stem from flying off resulting in abnormal rising of the inner pressure of valve, the stem with integral T-type shoulder supported by gland, can be guaranteed not to be blow-out by the medium even if at abnormal rising pressure in the cavity. In addition, in order to prevent leakage resulting from burnout of packing set of the stem in a fire, thrust bearing is set at the contact position of the shoulder at lower part of the stem and valve body, thus an inverse seal seat is formed which will prevent leakage and avoid accident.
2. Fire Safe design
When the Ball Valve are used normally, it is sealed by seat and ball surface, seat retainer sealed by O-ring and body, this is soft sealed and reliable sealing. When the seat and O-ring are burnt, the seat retainer and body will be sealed by expanded graphite, thus reach Fire Safe proof purpose.
3. Anti-Static Design
In order to prevent friction among ball, stem and PTFE that generates static electricity which may light the combustibles and explosives that cause an accident. In this ball valve, static-conduction spring is set between the stem and the ball, the stem and the body, thus static electricity is conducted to ground and system safety is secured.
4. No Leakage of Valve Body Sealed Construction
The Body & Caps are welded not bolted, so, no leaking paths through the joints.
5. Low Operation Torques
The seat and stem adopts SS304/SS316+PTFE bearings with small friction and self-lubrication, it can reduce the valve operation torques.The valve can be easily operated for long period even without sealing lubrication grease.
6. Double Block & Bleed (DBB)
When the ball is in the fully closed position, each seat of the ball valve can cut off the medium independently on the upstream and downstream side to realized double-block functions. The body cavity are isolated from each side of the valve, the body cavity pressure could be released through the vent valve and drainage plugs.
7. Emergency Sealant Injection System
For 6" and larger SBV Fully Weled Trunnion Mounted Ball Valves (Small size on request, if design is allowed), in case of fire or other accidents, the seat or stem O-rings are damaged and the valve got leakage, the special sealing grease may be injected through a sealant injection fittings that are located on the adapter and the gland to obtain emergent and temporary sealing function and prevent fluid leakage.
8. Stem Extension
For the underground installed valve, the stem can be extended and for the convenience of operation, the sealant injection system and drainage valve can be extended to the top of valve. The stem extension length shall be as per customer’s requirements.
9. Automatic Relief of Body Cavity
(Self Relieving Seat Design)-Standard Design
When the body cavity pressure exceed the downstream seat spring preloaded force, the differential force will push the downstream seat away from the ball, the body cavity pressure will be automatically relieved, and then the seat returns to the ball under spring pre-tighting action
10. Various Operation Types
The valve top working flange is designed according to ISO 5211,which is convenient for connection and change its drivers. The common operation types are manual (Lever/Gear Box), electrical, pneumatic and pneumatic/hydraulic.
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STANDARD COMPLIANCE 
