SED 024.16.720 - Features of the Valve Types

www.sed-owcontrol.com
15
System Description
Type 024.16.720
The position of the actuator is regulated according to the position set-point value. The position set-point value
isspeciedbyanexternalstandardsignal.
Pneumatically actuated piston actuators and rotary actuators can be used as an actuator. Single-acting
actuators are offered in combination with the positioner.
For single-acting actuators, only one chamber is aerated and deaerated in the actuator. The generated pressure
works against a spring. The piston moves until there is an equilibrium of forces between compressive force
and spring force.
6.3. Features of the valve types
Angle seat control
valves / straight seat
control valves
Diaphragm valves Ball valves Flap valves
Features incomingowunder•
seat
no closing impact•
straightowpathof•
the medium
self-adjustingstufng•
box for high leak-
tightness
medium is hermeti-•
cally separated from
the actuator and
environment
cavity-free and self-•
draining body design
anyowdirection•
with low-turbulence
ow
steam-sterilizable•
CIP-compliant•
no closing impact•
actuator and dia-•
phragm can be
removed when the
body is installed
scrapable•
minimum dead •
space
unaffected by •
contamination
little pressure loss •
compared to other
valve types
seat and seal can •
be exchanged in
the three-piece ball
valve when installed
Note
can be used as
process controller
only
unaffected by •
contamination
little pressure •
loss compared
to other valve
types
inexpensive•
low construction •
volume
Typical
media
water, steam and •
gases
alcohols, oils, propel-•
lants,hydraulicuids
salt solutions, lyes •
(organic)
solvents•
neutral gases and •
liquids
contaminated, •
abrasive and
aggressive media
media of higher •
viscosity
neutral gases and •
liquids
clean water•
slightly aggressive •
media
neutral gases •
and liquids
slightly •
aggressive
media
Table 1: Features of the valve types