Characteristics Of The Valve Types - Burkert 8630 Operating Instructions Manual

Pneumatically driven piston and rotary actuators may be used to operate them. Both single-acting and double-
acting actuators are offered in combination with TOP Control Continuous.
With single-acting actuators, only one chamber in the actuator is pressurized and vented. The pressure
produced works against a spring. The piston moves until an equilibrium is set up between the pressure and the
spring force.
With double-acting actuators, the chambers on both sides of the piston are pressurized. When the one
chamber is pressurized, the other is vented and vice versa. No spring is installed in this actuator version.

Characteristics of the valve types

Y-valves
Flat seat valves
• 2700
Types
• 2712
Characteristic • Inlet flow under seat
• Non-impact closure
• Straight flow of
• Self-adjusting packed
Typical media • Water, steam and
• Alcohols, oils, fuels,
• Salt solutions, lyes
• Organic solvents
Diaphram valves
• 2730 (plastic)
• 2731 (metal)
• 2731K (pipe housing)
• Medium is hermeti-
cally separated from
actuator and the
ambient
medium • Self-draining housing
design without dead
spaces
gland for very tight seal
• Either flow direction
with low turbulence
flow
• May be steam
sterilized
• CIP compatible
• Non-impact closure
• Actuator and dia-
phragm are de-
tachable with the
housing
• Neutral gases and
gases liquids
• contaminated, ab-
hydraulic fluides rasive and aggressive
media
(organic) • high purity or sterile
media
• high viscosity media
S
YSTEM
Ball valves Flap valves
• 2652 (2-part,VA) • 2672 (metal)
• 2655 (3-part,VA) • 2675 (plastic)
• 2658 (plastic)
• Piggable • insusceptible to dirt
• Low and dead space • less pressure loss
compared to other
• insensitive to valve types
contamination
• good value for money
• Lower pressure loss
than with other valve • smaller volume
types
• with 3-part ball valve,
seat and seal can be
exchaged while
installed
Note
Only usable as process
controller.
• Neutral gases and • Neutral gases and
liquids fluides
• pure water • slightly aggressive
media
• slightly aggressive
media
D
ESCRIPTION
8630 - 15