One piece body is used for the body to guarantee sufficient
strength and rigidity under maximum rated operating pressure.The
internal parts of valve are carefully designed and selected to
ensure reliability under all kinds of operating condition.Enough
margin wall thckness and adaptation of high strength connective
bolts are convenient for valve maitenance and sufficiency to
support the stress from piping.
Top entry
Its most difference from common ball valve is that its maintenance
can be made on pipe line and without dismounting from the pipe
line.The back space seat structure is adopted for the seat and the
rear portion of seat retainer is oblique angle to prevent
accumulation of impurity from affecting back space of seat.
Low operation torque
Top entry series ball valve has a trunnion mounted ball,whose
surface is ground,polished and hard face treated.The ball and stem
is integrated,sliding bearing is installed on the external bore so
that the friction radius is small and operation torque is very low.
Emergency sealing
Compound injection holes are designed and compound injection valves
are installed at locations of stem/cap and body support of side
valve.When sealing of stem or seat is damaged to induce leakage,the
compound can be used to do the second time sealing.A concealed
check valve is installed in side of each compound injection valve
to prevent compound from out flowing due to the action of
transmitter substance.The top of the compound injection valve is
the connector for fast connection with compound injection gun.
Reliable sealing
The seat sealing is formed by seat sealing and metal retainer
component.The seat retainer floats axially and low pressure sealing
of valve seat is reached by pre-pressure of spring.In addition,the
piston effect of valve seat is designed reasonably,which realized
high pressure sealing by the pressure of operating medium and
realize the interception of retainer to form the sealing of the
body.The expansion graphite ring is designed to realize sealing
under fire condition.
Double block&bleed(DBB)
When ball is full open or close position,the transmitter substance
in center cavity of body can be released by drainage and emptying
devices.In addition,the over loaded pressure in the center cavity
of valve can be released to low pressure end by self relief seat.
Anti-static and fire safe design
The fire prevention design of valve meets the requirement in
API6FA/API607 standard and the design of the anti-static conforms
to regulations in API6D and BS5351.
Extension stem
For the underground installed valve,the stem can be lengthened and
for the convenience of operation the corresponding compound
injection nozzle and drainage valve can be extended to the top of
valve.
Various driving types
The top pad of valve designed according to ISO 5211,which is
convenient for connection and exchange of various drivers.The
common driving types are manual,electrical,pneumatic and
pneumatic/hydraulic.
