Description
Features of Structure and Working Principle
1) Block-up
And Excretion
When the valve is in the
closed state, the seat ring on the upstream and downstream sides
cuts off the fluid and the accumulated matters in the middle cavity
of the body can be excreted, The excreting device features the
following functions:
Can check if the seat ring
leaks or gets damaged beforehand; Reduce pollution to the valve due
to the medium replacement; The packing on the stem portion can be
replaced when the valve is in the fully opened or closed state
under the working pressure.
2) Automatic
Pressure Discharge
When an abnormal pressure
rise occurs with the medium stayed in the middle cavity of the
valve due to rising temperature, the seat ring will come off from
the ball and automatically discharge pressure or the safety valve
mounted on the body ensures the system safety.
3) Complete
Seal
The unique sealing mode of
the ball valve makes the fluid completely cut off.
4) Fire-fighting
Structure
If the Teflon seat ring is
made softened and burnt in case of a fire or an abnormal
temperature rise, the valve can be contacted with the ball to act
as an instantaneous seal, conforming with AP***7.
5) Electrostatic-proof
Structure
During valve operation, the
friction between the ball and the PTFE seat ring will produce
electrostatic charges and they will be accumulated onto the ball.
To prevent electrostatic spark from being produced, an
electrostatic-proof device is mounted on the valve, which can guide
the charges out through the electric path formed by both ball and
via the spring.
6) Emergent
Rescue Of Sral
When the sealing parts of
both seat ring and stem get damaged and thus leaks are caused, an
instantaneous sealing action can be made available by injecting
sealing grease through the grease injecting valve.
7) Structure
Of Seat Ring
Two kinds:single-seal and
dual-seal. In general, those of an automatic pressure discharge
function are single-seal while the dual-seal means the additional
safety pressure diacharge to the body.
8) Full
Or Reduced Diameter
The valve nominal diameter is
identical to the inner diameter of the pipeline(which can be
reduced one if so required by users) for the sake of
cleaning.
9) Locker
Use a locker to fix the valve
so as to prevent maloperation of it and keep it in the correct
opened or closed position.
*0) Extension
Of Stem
Extension of the stem is
suitable for use under-ground and at low temperature, the extended
size is depended on the necessity and the operation mode can be
manual, pneumatic, electric, gas-hydraulic jointed or hydraulic
actuation, also upon the necessity.
*1) Reliability
Of Operation
The relative sliding
portion(seat ring and stem bearing) of a large aperture ball valve
has a small operational torque due to its use of Teflon which has a
small friction coefficient and can be flexibly operated for a long
time even if there is no lubrication supplied for it.
*2) Different
Actuation Modes
The used, different and
effective actuation modes include manual, qneumatic, electric,
hydraulic and gas-hydraulic jointed ones.
