For the purpose of preventing the stem from flying off resulting in abnormal rising of the inner pressure of valve, shoulder is fixed at the lower part of the stem. Additionally, 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. Therefore an inverse seal seat is formed which will prevent leakage and avoid accident.

 

2. Locking Devices (On Request)
To prevent wrong operations of valve switch and improper actions by unpredictable, vibration of the line, the valve is equipped with locking hole at the full open and full close position of the valve, and the valve can be locked with a pad lock. Especially this locking device is uniquely advantageous when the valve is installed outdoors or on the production line of flammable petroleum or chemicals.

SBV one piece Floating/Trunnion Mounted Ball Valve fire safe is designed in compliance with API 607-4^th, API 6FA and BS 6755 Part 2. Each possible leakage parts between body and ball, middle flange, body and stem is designed as metal-to-metal contact, when non-metal resilient seats are damaged in a fire or unusual temperature increasing, the upstream medium pressure push the ball into the downstream metal seat lip to cut off the line fluid and prevent the internal leakage dueo to a secondary metal-to-metal seals.

 

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.

 

The self-lubricated bearings are installed at the friction of stem, resulting in wear resistance, flexibility of operation and low torque.

 

The Top Working Pad of this valve is designed according to ISO 5211 (if design is allowed),which is convenient for connection and change its operation types. The common operation types are manual (Lever/Gear Box), electrical, pneumatic and pneumatic/hydraulic.