Control valves
Self-acting controls
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Steam
saturation
TI-P078-02
CH Issue 10
KA31, KA33, KB31, KB33 and KC31
Cast Iron
Self-acting Control Valves
Description
The KA, KB and KC range of two-port valves are used in
conjunction with Spirax Sarco SA control systems to provide a
self-acting temperature control unit.
Alternatively, they can be used as electrically actuated
temperature control valves by fitting an EL7200 Series electric
actuator with a suitable temperature transmitter and controller.
Available types
KA31 Normally open with screwed connections.
KA33 Normally open with flanged connections.
KB31
Normally open with phosphor bronze balancing bellows and
screwed connections.
KB33
Normally open with phosphor bronze balancing bellows and
flanged connections.
KC31
Normally open with stainless steel balancing bellows and
screwed connections.
Note: Pressure balancing bellows enables the valve to operate
against higher differential pressures.
Standards
These products fully comply with the requirements of the
European Pressure Equipment Directive 97/23/EC and carry
the
mark when so required.
Certification
As standard these products are available with a manufacturers’
Typical Test Report. Note: All certification / inspection
requirements must be stated at the time of order placement.
Pressure / temperature limits
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Sizes and pipe connections
Screwed BSP (BS 21 parallel) or NPT:
KA31 1⁄2", 3⁄4", 1", 11⁄4", 11⁄2" and 2"
KB31 1", 11⁄4", 11⁄2" and 2"
KC31 11⁄2" and 2"
Flanged EN 1092 PN16 and BS 10 Table F:
KA33 DN15, DN20, DN25, DN32, DN40 and DN50
KB33 DN25, DN32, DN40 and DN50
KA31 and KA33
unbalanced trim
curve
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Pressure bar g
The product must not be used in this region.
Body design conditions
Maximum design pressure
Maximum design temperature
Minimum design temperature
Maximum operating temperature
PN16
16 bar g @ 120°C
220°C @ 13.8 bar g
-10°C
220°C
0°C
KB31, KB33
and KC31
balanced trim
Minimum operating temperature
Note: For lower operating temperatures consult Spirax Sarco
Size
DN15 DN20 DN25 DN32 DN40 DN50
13.0
10.3
4.5
3.0
2.0
1.5
13.0
10.3
4.5
3.0
2.0
1.5
-
-
10.3
9.0
8.2
6.9
-
-
10.3
9.0
8.2
6.9
-
-
-
-
13.0
13.0
Maximum
KA31
differential
KA33
pressure
KB31
bar
KB33
KC31
Designed for a maximum cold hydraulic test pressure of 24 bar g
Local regulations may restrict the use of this product to below the conditions quoted.
In the interests of development and improvement of the product, we reserve the right to change the specification without notice.
© Copyright 2011
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