Valve and plant automation

The LEFF® function, which can be activated on any T.VIS® A-15 control top, is a stroke-dependent control of the lift function on mixproof valves, which makes the cleaning process of the valve discs and seals particularly effective. Compared to a standard cleaning sequence, activating the LEFF® function can greatly shorten the cleaning time and reduce detergent losses by up to 90%.

Not the control top per se, but the pilot valves are sensitive to oil, particles, or water content in the control air. However, the T.VIS has an integrated filter that protects it from excessively contaminated air by default. But in general, the control air quality standard specified in the operating instructions should be adhered to as far as possible to ensure the operational safety of the control top in the long term.

T.VIS control tops are equipped with a SETUP function so that they can be replaced even under operating conditions without having to move the valve itself to different end positions for the required SETUP. The T.VIS control tops A-15 and M-20 run the SETUP in-process, so no process interruptions are required.

Depending on the type of control top and requirements, the customer can choose between the common communication types 24VDC, AS Interface, DeviceNet and IO-Link. These available communication types ensure the exchange of input and output signals between the control top and the higher-level control system (PLC).

To determine the maximum number of ASi participants (control tops), it depends on the ASi version used. Our current control head portfolio uses the ASi version 3.0 with which you can operate up to 62 control tops within a network.

Pneumatic valves which are usually located in valve control tops. They react sensitively to the used operating medium, in this case control air. This air must therefore meet certain requirements, which are defined in ISO standard 8573-1:2010 in terms of solids content, water content and oil content in quality classes. Compliance with these requirements ensures operational safety over the specified life cycle.

The GEA valve portfolio includes a wide variety of variants, which allow different switching possibilities. Thus, in addition to single-seat valves, which can be used both as normally open (NC) and normally closed (NO), there are also shuttle valves. From GEA's point of view, it seems clearer for the customer to designate the position of the valve disc as start position (non-actuated position) and end position (actuated position). Especially with shuttle valves, an OPEN/CLOSED definition is generally not possible, since it is known that a changeover valve realizes two switching paths.

The GEA portfolio includes valve control tops for all common applications. We distinguish between Ex and non-Ex applications. For the operation of valves with control tops in hazardous areas, the portfolio includes a special ATEX certified version, which can be used for both dust and gas Ex applications using appropriate equipment.

Using control tops on process valves makes the process safer and servicing easier. Contact-free position detectors offer high-precision status information during operation. Digital feedback and control signals facilitate fast reaction.

Commissioning of the valve is done quickly and without specialist know-how, thanks to simple control air supply, standardized electrical connections and automatic SETUP.

360° visualization of the valve status ensures functional diagnosis under process conditions.

Internal air guidance within GEA valve units make air hoses between control top and the main valve actuator obsolete. The pneumatic connection is taking place inside the valve unit. The benefits of this include shorter reaction times, reduced errors from damaged hoses and minimum air consumption.

The electronic circuit built into every control top must be protected against chemical and mechanical hazards. GEA uses PA12 material with glass-fiber reinforcement, which is highly resistant against the aggressive chemicals in cleaning fluids. The injection molding tools have been refined with great care to achieve extreme mechanical resistance against vibrations in the system and improper handling, ensuring the availability and failsafe operation of the system.

The valve status can be checked on GEA control tops by means of a light dome. Its dome shape ensures great visibility, horizontally over 360 ° and generally from above. Via color signals, the valve status can be clearly identified. The light dome, like the rest of the housing technology, is extremely resistant, safely sealed and maintenance free, as it is integrated directly into the hood during the injection molding process.

GEA‘s VARIVENT® valve series has been known for decades to set the benchmark for hygienic valve technology. Its renowned modular concept employs an interface configuration that is highly established in the world’s markets to enable combinations of highly diverse components. This VARIVENT® interface also handles the connection between control top and valve actuator, and all GEA T.VIS® Control Tops as well as all GEA VARIVENT® actuators are compatible with it. This means, any control top can go with any actuator from the mentioned GEA series without need for adaptors – one size fits all!