VF-8 Series Triple-Offset Butterfly Valves

Value Valves
VF-8 Series
Triple-Offset Butterfly Valves
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VF-8 series, the triple-offset butterfly valve has to be put enough torque to the
shaft and turn the disc to fully dose position. Under such manner, the torque will
let the over all geometry of disc seal ring to be formed into an ellipse shape to
fully contact with the body seat and reach tight shut off. The unique design of
the sealing surface provided the higher sealing pressure to achieve bubble tight
shut off. The disc seal ring designed to be flex could self-adjustment in different
pressure and temperature and compress elastically on seating surface to
achieve the best sealing function.
Duplex stainless steel UNS 32205 Disc Seal Ring is using as aregular, both of
Laminated seat and metal to metal (Solid) seat are available on customers'
requested. Other than zero leakage level, also providing ANSI B16.104 CLASS
VI and CLASS V leakage class (Solid Seat).
Body seat is designed with Stellite 21 hard face overlay and providing the seat
has the long service life. Other hard face overlay materials are available on
customer request. In order to follow up future maintenance and repair, Value is
supplying separated body seat on the valves of 300# c1ass and up.
H The pressure af fluid reacls an lhe
surface af lhe disc (The blue
arrow) and forces laminaled seal
lo compress an lhe body seal.
The reacling force af body seal
(The yellow arrow) lo force disc
seal ring lo be formed inlo an
ellipse shape and fully conlacl wilh
lhe bodY seal; lhe compression
forces equally dislribuled around
the perimeler reach lighl shul off.
The disc seal ring designed lo be
flex could self-adjuslmenl (The
pink arrow) to achieve lhe besl
sealing. Il is self-adjusling.
(.
VF-8 series, provides a list of materials selection for body and disc. Expect
regular cast steel and stainless steel, also provide variety alloy steel as an
option to suit variety of service conditions and critical process conditions
requirements.
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.:l The VF-8 series of Value Valves Co., Ud. - which is a triple-offset designed butterfly valve.
It is the only company in Taiwan and one of the small number companies in Asia could
achieve bubble tight shut off. And a full series passed the fire test to APl 607, ISO 10497
and emission approval to TA-LUFT, ISO 15848-1 verified by TUV. There are more than
5,000 valves exporting to Americans, Europe, Asia and worldwide and being used in
various industries operating system.
B
VF-8 series, the triple-offset
butterfly valve is designed to be
90 degrees rotary and torque seated.
With 30 years of experiences in manufacturing
butterfly valve fieid, by using the geometry
and 3D software to back up updated manufacturing
and design. The triple-offset geometry provided that the
disc seat ring contacts body seat only at final fully closed
position, without rubbing to increasing the service life.
Smoother shape design of disc provides the better strength and flow.
At the same time, displayed the highest efficiency of the valve when
installed in the pipeline. All the valve's strength was designed to
APl 609, APl 598, ASME 816.34 accordingly.

mi THE ANALYSIS FORCE
mi THE ANALYSIS RESULTS
Element
By using 3D software and CAE to
analyse and determine the shape and
thickness of the disc.
Displacement
Stress
B Offset 1
The shaft is offset behind the axis of
seating face, thus allowa complete
sealing contact around the entire seat.
B Offset 2
The centerline of shaft is offset from
the valve and pipeline which provides
the valve disc opening and dosing
without interference.
I Offset 3
The seat cone axis is offset from the
shaft centerline to prevent the seat
from rubbing and galling during
dosing and opening the valve. And
provides the more torque you dose
the valve the tighter you get, never
over dose the valve.
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m THE BOTTOM SHAFT
In order to strengthen the
structure of valves, ane-piece
shaft design on the valve sizes
24" and smaller. In arder to
enhance the environmental
protection, the finish af the
shaft's surface shall be better
than Ra 0.4 and Ra 1.25 for
shaft hole of body.Hard chrome
plated surface to pass the test
of the low vac emission and
abrasion resistance of shaft
during long working period.
Dust-proof design
The shaft was centered by
two lang bushings, nitried and
chrome plated protected
against the entrance of solids
by dust-proaf seal to prevent
the shaft stuck.
,
Anti blowout design
~------ Thrust ring
\---- Lock plate
The bushing could suit different
pressure and the service
temperature between
-321-1400°F~196-760°C).
Double shaft blowout protection design
could meet APl 609 requirement and
provide anti-static at the same time.
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• STANDARD GLAND PACKING
The valve shaft sealing device is using
combined gland packing rings that
could provide a good service under high
temperature and chemical resistance
and easy to maintain as well.
Standard gland packing could suit
general conditions, double gland
packing with lantern ring also could be
available on customers' requirement.
• DOUBLE SEALlNG WITH LANTERN RING
Except standard graphite gland packing, the addition live-Ioading
gland can be available for high cydes and low emission
services. Special compound of graphite packing materials are
also available to provide the low VOC emission, which was
verified by Metal Industries Research & Development Centre to
ISO 15848-1 accordingly.
Live-Ioading
Purge port -#--.......
(
Lantern ring (An optional)
• 1 • V r ~ "I' I
, I \
I". _ ,.
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• THE INTERFACES OF VALVE
The interfaces of valve, such as shaft, mounting detail of body and yoke are
according to ISO 5211 and easy to install actuators. The face to face dimension
of valve followed ISO 5752 or/and APl 609.
Shaft's scratch to
indicate disc position
ISO shaft out put
It can be easy to recognize
the disc position from the
scratch at the end of shaft,
which indicates the position
of the disc.
'\
)
Yoke with ISO
mounting flange
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The heating jacket and flashing nozzles designed which apply to the temperature
changes and prevent fluid crystallization. Value Valves VF-8 series, triple-offset
butterfly valve can be provided on customer's requirements. More detail please
consult with us at sales@valuevalves.com.tw .
H VF-877J
VF-880L B
Il VF-887J
80dy style : Wafer type, Lug type, Flange type
80dy shell thickness : ASME 816.34
Mounting : ISO 5211
Design & Pressure : ASME 816.34
Face to Face: APl 609, ISO 5752
Inspection and Testing : ISO 5208, APl 598
Firesafe : APl 607, ISO 10497
VOC: ANSI/ISA-SP-93, TA LUFT, ISO 15848-1/-2
Cryogenic : 8S 6364
Standard Marketing System: MSS-SP-25
EX certificate : ATEX
Leakage Class: ANSI FCI 70-2-2003 TA8LE 1, ISO 5208 RATE D/A, ANSI/ISA-SP-93
Flange connection : ASME 816.5 Class 150/300/600, ASME 816.47 Class 150/300/600
(Other flange connection please contacts with Value Valves Co., Ud.)
*Technical information is only for reference. Value Valves Co., Ud. reserves the right to change wilhout previous notice.
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