DN1200 High Performance Butterfly Valves , WCB Double Eccentric
The high performance double-eccentric butterfly valve can be used
in working conditions and media for which conventional valves are
suitable, and adopts different structure materials and special
treatment materials according to different media. It can also be
used in special working conditions such as cryogenic condition,
steam, chlorine, oxygen, high vacuum, anti-corrosive condition,
The series of high performance wafer type butterfly valves uses
various structure materials, including those that meet NACE
requirements and anticorrosive materials. Special valves that can
be used in chlorine, oxygen, high vacuum, corrosive media and
cryogenic condition are also available.
The unique dynamic load seal PTFE seat design is adopted with good
elasticity and high reliability.
Sealing can be maintained without the need of adding O ring or
The lip type sealing structure can compensate for the changes of
temperature and pressure.
Long service life and low maintenance.
In seal test, there is no bubble and leakage at both directions.
► Seat type
PTFE, R-PTFE, PEEK, Fireproof seat, etc.
► Reliable fixing of shaft
The anti-blow-out structure is provided at the top of the shaft to
prevent the shaft from running out of the gland in case of
accidental breaking of the shaft.
► Convenient seat maintenance and servicing
The seat can be replaced just through removing the inserts without
removing the inserts without the need of disassembling the
butterfly valve and shaft.
► Provided with shut-off and control functions
Having excellent control characteristics
Proportional change of flow characteristic curve
Wide adjusting range
Tight sealing can be realized even when it is used for control.
Unique seat sealing structure-Butterfly valves
The traditional central line butterfly valve is lined with fluorin
or rubber, but the S type elastic seal seat structure independently
researched and developed by our company through introducing
technology from Germany MAYER adopts the imported RPTFE material
with good elasticity and long service life. It can automatically
compensate for the changes of temperature and pressure and can
realize compensation for the worn seal due to long-time opening,
closing and use. It can realize double-direction sealing without
leakage. It adopts flexible insert structure, and the maintenance
is fast and convenient without the need of removing the butterfly
plate and stem. The seal seat can be replaced and the sealing face
can be repaired just through taking off the inserts at one side.
Seat sealing-Butterfly valves
►ANSIFCI 70-2 stipulated the control valve leakage level and test
procedures. Among them VI level is the minimum leakage level. High
performance wafer butterfly valve can achieve MSS-SP61 prescribed
no bubble seal, higher than VI level.
►When the valve is closed, the butterfly plate makes the seat
slightly deform. The deformation excites the seat. The excitation
of the seat sealing face enables permanent sealing to be maintained
between it and edges of the butterfly plate.
►When the inserts receive pressure, the pressure is exerted at the
bottom of the lip edges, further enhancing the sealing force
between the butterfly plate and seat.
►When the pressure is exerted at the non-insert side, the butterfly
plate is pushed towards the seat. As the butterfly plate is of the
ball shape, the further the butterfly plate is pushed towards the
seat, the tighter the closing is. The lip edges contact the trough
at the bottom of insert, limiting excessive movement of the seat.
Valve size table-Butterfly valves
|Approximate size (mm)||Weight(kg)||National standard flange GB PN16|
|Approximate size (mm)|
|National standard flange GB PN16|
Special working conditions-Butterfly valves
►Steam working condition
The wafer type butterfly valves, including valves of PTFE seat with
lower rated values and valves Peek seat, are suitable for steam
working condition. The rated values of valves used as switch in the
steam working condition are shown in the following table. The rated
values may be decreased according to different shaft materials
►Oxygen working condition
After special treatment, the valve can be used for shut-off and
control in oxygen working condition. A series of strict procedures
for spare parts preparation, assembly, teat and packing is followed
to ensure cleanliness and avoid inherent danger caused due to
reaction of oxygen with grease and other impurities.
►Vacuum working condition
Standard wafer type butterfly valves are rated for tight shut-off
of vacuum 2X10-2torr. Special high vacuum wafer valves can also be provided for
vacuum of 2X10-5 torr. In addition, high vacuum valves are confirmed to have a
leakage rate of helium not exceeding 2X10-5 CC/sec at vacuum of 2X10-5 torr.
►Selection for high service life
The service life of valves assembly by spare parts such as
reinforced PTFE shaft seal, PEEK-reinforced PTFE thrust bearing,
etc. is much higher than that of ordinary valves. Certainly, the
actual performances depend on the media, pressure and temperature
and other conditions. It is the most ideal situation that the
combination of oxygen, nitrogen, hydrogen, water and clean media is
Note: The working condition that contains acid, chlorine, bromine,
sulfur dioxide, steam media with temperature exceeding 325°F(163℃)
shall be avoided.
►Body rated value
The maximum working pressure of body and testing pressure of body
of various materials are listed in the body pressure ratings table.
The actual working pressure in the working conditions shall be
decided according to the seat rated values.
|Rated value of 150lb body (bar)|
|Temperature||Carbon steel||Ductile iron||Stainless steel||20# alloy||Monel|
|-20 to 38||19.7||17.2||19.0||15.8||15.8|
|Rated value of 300lb body (bar)|
|Temperature||Carbon steel||Stainless steel||20# alloy||Monel|
|-20 to 38||51||49.6||41.4||41.1|