|Floating Ball Valve|
A floating ball valve is a valve with its ball floating (not fixed by a trunnion) inside the valve body; it drifts toward to the downstream side and tightly pushes against the seat under the medium pressure to ensure a reliable seal. The floating ball valve is a simple design with good sealing performance relying on the seat material to withstand the workload as the sealing pressure is barred by the seat ring. Floating ball valves are mainly used in low to mid level pressure applications. FBV manufactures the floating ball valve class 150 to class 600.
Reliable Seat Seal
The design element of the double-beveled sealing ring has been adopted to reduce the friction between the ball and the sealing ring achieving lower operation torque. When the medium pressure is low, the ball has less surface area contacting the sealing rings, which introduces higher sealing pressure to ensure the sealing reliability. When the medium pressure gets higher, the contacting area between ball and sealing ring increases accordingly. Larger contact area reduces the sealing pressure to avoid the deformation of sealing ring.
Fire Safe Design
In case of fire, non-fireproof material for packing and seat will be burnt-out and considerable medium leakage may possibly cause the fire to spread. FBV adopted metal to metal seals as an auxiliary safeguard to prevent medium leakage in cases of fire as shown in figures. The fire safe design confirms to the requirements of API607, API 6FA, BS 6755 and JB/T6899.
Reliable Stem Seal
The blow out proof design for the stem assures that even if the pressure in the body cavity has risen accidentally and the packing flange breaks, the stem cannot be blown out by the medium. The stem features a backseat, assembled from within the body. The sealing force against the backseat gets higher as the medium pressure becomes higher. Therefore, a reliable stem seal can be assured under variable medium pressures. The stem cannot be removed during service.
V type packing material has been employed to effectively transform the pushing force of the gland flange and the medium pressure into a sealing force against the stem.
Based on customer requirements, a live loaded gland flange can be ordered for low emissions valves using a set of Belleville springs installed on each gland stud to provide a continuous compressive force on the gland, which guarantees permanent load retention for the stem packing to avoid fugitive emissions
To prevent electrostatic charges from building up within the valve, an antistatic device is placed between the ball and the stem or between the stem and the valve body.
To prevent unauthorized operation, the fully opened or closed position of the valve can be locked, especially useful when the valves are mounted outdoors or when valves may be opened or closed by unauthorized persons. A lockable hole on the pad is a standard feature.
Mounting Pad Provided
The mounting pad is a standard feature for easy installation of worm gear, pneumatic or electric operators.