-Structural Features: API Floating ball valve
-Float ball valves are superior products developed upon the advanced technology
home and abroad Provided with updated design ideas．they meet the requirements
on safety and convenience in general industrial standards
1 Switch Indication of Hand 0perated Float Ball Valve
As the moving parts of valve，ball．valve stem and handle are an assembly
unit The head of valve stem is shaped a diploid thus to easily distinguish whether
valve is in the。ON。position or。0FF。position from handle position When handle
or stem diploid is in parallel with the pipe axis valve is in。0N‘position；when handle
or stem diploid is vertical to the pipe axis valve is in。OFF。position
2 Valve Locking Device
To prevent misoperation，the fully opened or closed position of valve can be
locked up，especially when valves are mounted outdoors or when valves are not
allowed to be opened or closed by technical process To prevent misoperation by
other persons，it seems very important to have valve position locked up Thereby，
lockhole locating ab is designed if requested by users to meet the technological
requirements of users
3 Anti—flyout Structure of Valve 8tem
When medium passes through the valve，the pressure in valve body may
possibly push the stem out，or when the valve is in repair，if there is pressure in
the middle cavity．the stem or medium seems to easily fly out upon disassembling
the valve which can cause injuries to human beings To prevent these possibilities
a dummy club Is placed at the lower part of the stem In this way．even if there is
fire，packing and the rust bearing are burnt or packing is damaged due to other
causes．the pressure of medium in valve body will make the dummy club of valve
stem in close contact with the upper seal face of valve body．Thus to prevent medium
leaking out from the damaged packing position
4 Antistatic Device
When operating the valve，the friction between the ball and the nonmetal seat．
1ike PTFE or etc will produce electrostatic charge that can be accumulated on the
ball To prevent static spark an antistatic device is placed on the valve to derive
the electric charge accumulated on the ball from the static channel between the ball
and the stem，or between the stem and valve body
5 Fire Protection Structure
In case of fire．the nonmetal packing or seat(non—fireproof material)will be
burnt．the considerable medium leakage may possibly cause fire spread Here，the
fire protection structure functions to prevent medium from mass leakage As shown
in the figure once the seat is burnt the ball will directly contact the metal face on
valve body thus to prevent medium leaking out from the burnt seat The design of
fire protection and antistatic structure shall conform to the requirements of APl607．
JB6899 and the second part of BS6755
6 Middle Flange Leak-tight Structure
The connection between valve body and the left body is sealed by gasket To
prevent seal leakage resulted from fire high temperature or vibration etc the valve
body and the left body is designed metal—to—metal contacted thustofor|11 up a seal
flange to ensure leak—tightness
7 Dependable Seating Structure
The two-way sealing structure embodying the years of our manufacturing experience in ball valves and the internationally advanced technology can release the pressure at valve seat and ensure reliable seal under high or low pressure and vacuum state When the pressure of medium is IOW the contact area between valve seat insert and ball is relatively small，thus providing high sealing load to ensure dependable seating seal When the pressure of medium Is high，the contact area between valve seat insert and ball is relatively large，so that the valve seat insert can endure the considerable medium thrust and cannot be damaged
Regarding ball valves of very low working pressure．in consideration that the pressure of medium cannot guarantee the dependable seal of valve seat．and that the pretightening force will decrease after a long time of service，so we apply leaf spring loaded seating structure for valves working under IOW and ultralow pressure or under vacuum conditions。thus to ensure persistent and dependable seal
The seating structure of medium and high temperature ball valves use PPL for seal ring that carl serve a temperature of 300℃Ball valves
with metal seal and high temperature resisting materials can be used to deal with even higher temperature This structure takes the function of one—way seal
8 Self-relieving Structure
In case of abnormal rise of pressure in the middle cavity of valve resulted from the medium left there suffered from changes of pipeline pressure or medium temperature automatic pressure relief of valve seat can be effected under the pressure of the medium itself, thus to guarantee the safety of valve
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