15
Type 8692, 8693
english
Description of System
Pneumatically actuated piston actuators and rotary actuators can be used as a actuator. Both single-acting and double-acting
actuators are offered in combination with the positioner.
For single-acting actuators, only one chamber is aerated and deaerated during actuation. The generated pressure works against
a spring. The piston moves until there is an equilibrium of forces between compressive force and spring force.
For double-acting actuators the chambers on both sides of the piston are pressurised. In this case, one chamber is aerated when
the other one is deaerated and vice versa. In this design, no spring is installed in the actuator.
1.2 Features of the valve types
Slanted seat control
valves / screw-down
stop globe control
valves
Diaphragm valves Ball valves Flap valves
Types
2702•
2712•
2300•
2301•
2730•
2103•
2731•
2652•
2655•
2658•
2672•
2675•
Features
incoming flow under •
seat
closes smoothly•
straight flow path of •
the medium
self-adjusting stuffing •
box for high leak-
tightness
medium is hermetically •
separated from the
actuator and environ-
ment
cavity-free and self-•
draining body design
any flow direction with •
low-turbulence flow
steam-sterilizable•
CIP-compliant•
closes smoothly•
actuator and •
diaphragm can be re-
moved when the body
is installed
scrapable•
minimum dead space•
unaffected by contami-•
nation
little pressure loss •
compared to other
valve types
seat and seal can •
be exchanged in the
three-piece ball valve
when installed
Information
Can be used as process
controller only
unaffected by contami-•
nation
little pressure loss •
compared to other
valve types
inexpensive•
low construction •
volume
Typical
media
water, steam and •
gases
alcohols, oils, propel-•
lants, hydraulic fluids
salt solutions, lyes •
(organic)
solvents•
neutral gases and •
liquids
contaminated, abrasive •
and aggressive media
media of higher viscos-•
ity
neutral gases and •
liquids
clean water•
slightly aggressive •
media
neutral gases and •
liquids
slightly aggressive •
media
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