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Tube Products International May 2013
valves , f i t t ings , f langes
and connectors
nectors
International Tube & Conduit Company Ltd.
• British Standard Conduits BS31 / BS4568
• Electrical Metallic Tubing
EMT
• Intermediate Metal Conduit IMC
• Rigid Metal Conduit
RMC
• Flexible Conduit
FC
• Fittings
T: +966 2 6060275 - F: +966 2 6061095 - P.O. Box 10374 Jeddah 21433 - KSA
E-mail:
-
Compact cryogenic valve with integrated
pneumatic actuator
Stöhr Armaturen designs and
manufactures valves for industrial gas,
chemical and pharmaceutical industries,
for applications in aerospace, marine
engineering and energy engineering as
well as in research institutes.
Its standard product range consists of a
variety of globe or control valves, check
valves, pressure relief valves and filters
in different body types with diameters
up to DN250.
Valve bodies are made from a single
piece of stainless or special steel, and
are sealed with bellows.
A variety of connections and surface
treatments are available, along with
special designs for specific customer
requirements in terms of temperature
range, pressure range, life cycle
extension or materials.
Cryogenic valves are typically space
consuming, due to the large distance
between the actuator and the medium.
Conventional actuators lose power
when they are exposed to temperatures
below -40°C.
Conventional cryogenic valves are
therefore designed with long valve body
and stem to position the actuator as far
as possible from the cryogenic medium,
to avoid freezing and condensation.
Using the new FREES compact
technology, Stöhr Armaturen has
developed a very compact valve
with an integrated actuator. The
claimed advantages of the valve
include pneumatic drive suitable for
use in cryogenic applications (down
to -196°C); maximum possible height
reduction, total weight reduction, and
smaller footprint of the actuator; and
unrestricted fitting position in vacuum-
insulated pipes, including upside-down
installation.
The 6-bar industry standard for the
operating pressure of pneumatic
valves is retained, and maintainability
of the valve stem and actuator allows
installation and removal of the actuator
and valve insert unit without opening
the vacuum system. Change of actuator
can be performed without opening
the media space, which means that
no system downtime is required. In
addition, life cycle of the pneumatic
actuator is extended by replacing O-ring
seals with bellows.
For the prototype a number of different
ideas were implemented, such as using
the dead space for functional units,
avoiding long valve stems, replacing
stainless steel components with
alternative materials, using stainless
steel pneumatic cylinders of variable
length, and separation of mounting and
sealing forces.
New features include the replacement
of heat-transmitting stainless steel
components by special cryogenic-grade
plastics, including pressure and force
transmitting parts in cryogenic areas
such as the valve stem. In addition,
minimised frictional forces and an
overall low-wear design were achieved.
Stöhr Armaturen GmbH & Co KG
–
Germany
Stöhr compact valve with integrated actuator
