GEA VARIVENT D Series, Operating Instruction

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3.2 Functional description
3.2.1 Leakage-Proof Shut-Off
Fig.6
On the double-seat valve D, the upper and the lower valve housings are each
equipped with a valve seat. The chamber between the two valve discs is
connected to the open air by an isolation outlet (15.1) integrated into the lower
valve disc. In the event of seal damage, the leaking fluid can safely flow into the
open.
Defective seals can thus easily be detected. Under normal operating conditions,
liquid from one pipe is prevented from entering the other pipe.
3.2.2 Cleaning function
The cleaning of the leakage drain system occurs independently from the opening
and closing of the valve.
A cleaning liquid is supplied to the leakage drain system via a separate
connection (11.1) arranged in the lantern. The cleaning fluid is sprayed into a
cavity between both of the valve discs over a ring nozzle (74) and flows out
through a drain free of pressure. The cleaning of the leakage drain system occurs
independently from the opening and closing of the valve.
The cleaning fluid flows out of a CIP-cleaning unit.
Cleaning fluid data:
• Service pressure: min. 2 bar (29 psi), max. 5 bar (72.5 psi)
•
Service temperature: max. 135 °C (275 °F)
3.2.3 Actuator Function
The actuator is of the spring-closing type (Z). The valve is closed in the non-
actuated position.
Identification on the T.VIS control top once the installation (SET-UP) has been
completed:
• Green steady light (1): valve in non-actuated position
•
Yellow steady light (1): valve in end position (actuated position)
Description
Functional description
430BAL008360EN_5
07.02.2022 19