The securing of the tanks against overpressure happens via VARIVENT® safety valves and VARIVENT® vacuum valves against vacuum.
Via only one central connection will gas and CIP paths switched. The CIP / gas management can be done by an automatic switchover module (no extra power supply required) or by a butterfly valve combination. The cleaning medium is guided through the CIP supply pipe to the cleaning lance or jet cleaner into the tank. If no cleaning process takes place, the gassing and degassing is ensured by a bypass on the cross piece and the switch module.
The tank safety system VARITOP® can be placed on a central connection or a tank plate. The interface is always the proven VARIVENT® flange connection on the cross piece.
VARITOP® tank safety systems are widely used in the brewing industry. A typical application is the protection of tanks in the fermentation and storage area. The pressure regulation in the headspace of the tank during fermentation and storage can be done via the VARITOP®. At the same time VARITOP® system secures the tank against over and under pressure during filling and emptying.
The optional heating of the vacuum valve as well as the safety valve allows the use of VARITOP® outdoors. Prerequisite is a reasonable protection against weathering (e.g. housing).
The CIP/Gas Management takes place without power supply via a switch module or with power supply via a shuttle valve or a modulating control valve with butterfly valve or a butterfly valve combination.
Path I: open
Path II: open
In idle position of the tank, the switch module keeps the path for tank gassing and degassing open. The path to the cleaning device is always opened.
During CIP supply to the cleaning lance the switch module is switching automatically as of 10 m3/h. The rotating jet cleaner is an exception: The switch module closes here at 8 m3/h. With the closing of the switch module the path for tank gassing and degassing is closed.
Please note for dimensioning! The pressure dependent gas pipe is designed for a flow rate of max. 92m3/h CO2 at an operating pressure of 2 bar g. This is convertible to other process parameters. The switch module is self-cleaning.
Path I : closed
Path II: opened
In idle position of the tank, the switch module keeps the path for tank gassing and degassing open. The path to the cleaning device is closed. Pneumatic path switching is provided. The path to the cleaning device is then opened and the gassing/ degassing path closed. The switch module is designed for higher gas rates.
Path I : closed
Path II: opened
The switch module regulates gassing and degassing according to the operating and process parameters via path II. This is a compact way to control the pressure during the fermentation process.
The control valve is designed as T-smart 7 butterfly valve in combination with a T.VIS® P-15 is provided in the path II. Path I is closed by a T-smart butterfly valve in combination with a T.VIS® M-15 then.
In the central connection the safety and vacuum valve is cleaned by the cleaning lance or the jet cleaner. The cleaning medium is sprayed by nozzles in the lance to the valve seats. To ensure that the valve seats as well as the housing be cleaned, the valve plate can be lifted (optional). In the tank dome cover version the safety valve is standing mounted on the tank plate. The valve is cleaned by a separate cleaning module, which is mounted between the tank plate and the safety valve.
The tank cleaning can be done via a cleaning lance or jet cleaner. By using of a cleaning lance several cleaners can be foreseen. E.g. spray balls, orbital or rotating cleaner.
The cleaning lance or jet cleaner is mounted on top of the cross piece and extends through the cross piece in the tank. Nozzles in the lance tube secure the self-cleaning of the cross piece during tank cleaning.
The automatic switching module needs a minimal flow rate to close. This flow can be higher than the required flow rate for the cleaner. The switching module has cleaning gaps which ensure the cleaning of the pipe to the crosspiece in the closed position during tank cleaning.
In the tank safety system VARITOP® numerous cleaners from GEA can be used. The use of cleaner in the VARITOP® has technical differences in contrast to the single use. Please note the following calculation of the total required flow rate for the system VARITOP®. The maximum allowable working pressure for all installed cleaners is 10 barg. Cleaners will adapted via the cleaning lance in the VARITOP®.
At the proven cleaning principle of the jet cleaner the optimum cleaning result is achieved by slowly rotating, powerful surface radiation.
They are type-tested for fluids and/or steam / gas or subjected to special approval from ASME, TÜV, Stoomwezen, CRN, ISPESL and others.
Reliable tank protection by modern safety valves. The installation position of safety valves may be vertical or horizontal so that they perfectly fit into the given place of installation. As a matter of principle the set response pressure is lead-sealed. Optional equipment and connection fittings are available such as CIP module, pneumatic lifting actuator and feedback of the valve position. If vacuum occurs in the tank without protection, the tank or the product may get damaged or in less serious cases, the product may degas and get damaged. Response behaviour as of 2,5 mbar and tightness in case of minimum overpressure.
The safety valve can be placed vertically or horizontally within the VARITOP® system. The inside of the vertical safety valve on the tank lid can be cleaned with a special cleaning module.
Tests / Inspections
The supplied safety valves undergo a component test every five years by the request of the pressure vessel regulation, AD instruction sheet A2 and VdTÜV instruction for safety valve 100. Therefore the test is assessed according to German rules. The valves are also checked annually for conformity with the component parts test.
Safety valve type 488 can be supplied with special certificates which adhere to the international regulation offices e.g. ASME, DIN, GOST, ISPESL, CBPUI etc. These individual certificates also cover the implementation of the correct testing pressure.
* The horizontal application must be notified when ordering. For other medias with a higher viscosity, like water or beer, the varying characteristics need to be taken into consideration. Characteristics like bending to stick or verifying chemical behaviours.
The VARITOP® Tanktop System uses exclusively GEA vacuum valves. This valve shows a very sensible response behaviour and a high air throughput. The hygienic design ensures that no deposited dirt particles or dust are drawn into the tank. The valve opens as of 2,5 mbar (equal to 25 mm WC). The virtually non-adhesive coating of the valve seat and disk enhances the response behaviour. The integrated soft seal supports the sealing function of the valve in case of overpressure so that a slowly generating overpressure can be maintained. Optionally, the vacuum valve may be equipped with a pneumatic lifting actuator, heating and feedback of the valve position.
The VARIVENT® Vacuum valve type V makes tanks safe when under pressure builds up.
Structure: Valve for securing tanks against vacuum pressure
Opening characteristics: From 2-3 mbar the valve "swims" open, emerges well-balanced under pressure. From 5 mbar the full lift is reached. The valve is immediately closed by overpressure
Additional information:
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