APPLICATION CODE
API 607 - 4th Edition
QUALIFIED RANGE
CLASS RATINGS: Up to class 600
SIZE: All Sizes
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TEST RESULTS |
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Test
Measure |
Allowable
leakage rate
( ml/Min./NPS ) |
Test
Result
( ml / Min.. / NPS ) |
Seat
Leakage
(During the burn period) |
100 |
0
Zero leakage |
External
Leakage
(During the burn and cool down period) |
25 |
0
Zero leakage |
Seat
Leakage
(After operation) |
20 |
0
Zero leakage |
External
leakage
(After operation) |
25 |
0
Zero leakage |
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MANUAL GEAR
OPERATION
PK valves adopt a worm gear operation served as a standard of
PK.
This type of valve has advantages of large output and easy
operation due to high gear ratio, so that it is used extensively
for quarter turn valves.
The gear constructed by self-locking mechanism is suitable for
triple offset valves whic require torque seating. Clockwise
turning of handwheel makes valve closed and counterclockwise
turning makes valve opened. |
ELECTRIC MOTOR ACTUATOR OPERATION
This valve is operated by an electric signal coming from
electric motor to open, close or stop the valve in the
process of operation. Position limit switch or torque switch
signals stop at full open or close. Electric motor actuator
is applied mainly to large size or high pressure valves
because of greater torque over pneumatic actuator.
This type has advantages of simple wiring and good response.
In addition, a remote control is available, and therefore
the valve can be applied to a dangerous or limited space
where it is difficult for man to access.
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PNEUMATIC
ACTUATOR OPERATION
This type of valve is operated by a signal of air pressure,
which is normally 2-9 kgf/crrl in
control parts. There are two operating methods; single acting
and double acting. Single acting actuator is divided into full
close and full open according to spring acting orientation. It
is useful for control valve by virtue of its characteristics of
safety and easy handling.
Besides, the construction is more responsive than electric motor
or hydraulic actuator.
Double acting actuator is served as PK standard with air
regulator, solenoid valve, and position indicator types.
However, PK is able to make whatever customer wants.
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WAFER AND
LUG TYPE
API 609 Table 2./ MSS-SP-68 Table 1
Class 150 & 300 : 3" ~ 24"
Class 600 : 3" ~ 12"
ISO 5752 Table 5
Class 150 & 300 : 28 " ~ 48"
Class 600 : 14 " ~ 24"
DOUBLE FLANGE
ISO 5752 Table 4, BS 5155 Table 6(short) Class 150 & 300 :
3" - 24"
ISO 5752 Table 4, BS 5155 Table 6(long) Class 600 : 3 " - 12
"
ISO 5752 Table 4, BS 5155 Table 6 (short)
Class 150 & 300 : 28 " ~ 80"
ISO 5752 Table 4, BS 5155 Table 6 (long) Class 150 & 300 : 3
ff ~ 80 ff Class 600 : 14 ff ~ 24 ff
ASME B16.10
Class 150 & 300 : 3 " ~ 24"
Class 600 : 3 " ~ 24 "
BUTT WELDING
ISO 5752 Table 4, BS 5155 Table 6 (long) Class 150 & 300 : 3
" ~ 80"
Class 600 : 3 " ~ 24"
END FLANGE
ASME 816.5 : Class 150, 300, 600
JIS 82210 : 10K, 16K, 20K, 30K, 40K
DIN, ISO PN10, PN16, PN20, PN25, PN40
ASME B16.47 series A: Class 150, 300 MSS-SP-44 : Class 150,
300, 600 BS 3293 : Class 150, 300
MOUNTING FLANGE
ISO 5211
TESTING
API 598
MSS-SP-61, ANSI 816.104 |
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TRIPLE OFFSET DESIGN
PRINCIPLES
PK triple offset metal seat butterfly valves provide a bi-directional and
bubble-tight shutoff which is attributed to the
geometry of triple offset seat.
The valve stem is offset by seat (1 st offset) and the valve
seat surface center line is offset against the center line
of pipe (2nd offset) and the conical axis is offset by valve
center line (3rd offset: inclined cone). The 3rd offset
completely eliminates rubbing.
The seat surfaces of body and seal ring in triple offset
valve contact with the inclined "cone-in-cone" and this
design requires excellent sealing and seat part durability
by slight wedging effect.
In addition, the angle of contact between body and seal ring
has a good sealing performance by low torque because the
angle travels the initial torque from actuator to seat parts
without any loss by jamming.
This valve is characteristic of concentric, offset and
double offset construction with remarkable sealing
performance and seat part durability, and moreover it is
hardly needed to repair. |
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CHARACTERISTICS AND MERITS
- Excellent durability of seat
part and low operating torque by non-rubbing characteristics with
triple offset construction.
- Bi-directional zero leakage
service by resilient metal sealing and torque seating.
- Unrestricted selection of face
to face dimensions for API, ASME(ANSI), BS, ISO, etc. and perfect
interchangeability of gate, ball, plug, high performance
butterfly, and other valves.
- Low emission by quarter turn
construction and good performance at automation by virtue of low
operating torque and low cost.
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BODY
- The valve body shall be one
piece cast or fabrication.
- The body can be supplied
with different types of materials in wafer, lug, or flanged
and butt welding end connections to satisfy all installation
requirements.
BODY SEAT
- The valve seat shall be
integrated with the body.
- Stellite or stainless steel
shall be applied on the seating surface of valve body.
- The valve seat is designed
for inclined cone to ensure non-rubbing, non-jamming,
bi-directional shutoff, and zero leakage.
DISC
- The valve disc shall be the
same material as the valve body. It is supported by laminated
seal ring, which is kept in place by seat retainer ring bolted
to the disc and can be replaced easily.
- The spiral wound gasket
shall be provided between laminated seal ring and disc.
SEAL RING (LAMINATED)
- The seal ring shall be
resilient stainless steel lamella alternated by graphite,
aramid fiber & cermic fiber layers.
- The surface contacting
between seal ring and body seat is an inclined cone type and
the inclined angle generates a slight wedging effect.
- With a seat retainer ring
bolted to the disc, the seal ring is fixed to disc not too
tightly to be replaced easily.
STEM
- The stem shall be stainless
steel and one piece & two piece construction.
- The stem shall be fixed to
the disc by pin or in combination of pin and key. It can be
protected by internal thrust bush and bush bearing.
- The thrust bush and bush
bearing shall be provided to locate the valve disc in a proper
position.
- The retainer ring shall be
installed to avoid blowing out the stem.
PACKING
- The packing shall be consist
of two braided rings in the top and bottom of valve and three
die formed graphite rings in the middle.
- The lantern ring may be
provided as required by customer.
ACTUATORS
- All valves shall be
self-locking manual gear operation type which is served as
standard. . Electric, pneumatic or hydraulic actuator may be
provided as required by customer.
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