When looking for a valve that is easy to clean and suitable for CIP/SIP processes, a diaphragm valve is usually the ideal choice. However, diaphragm valves soon reach their limits when a fine batch is required or a large control range must be covered. Although globe valves with flow restrictors offer precise control, they are not aseptic. The effect of the valve spindle passing back and forth through seals means that medium is often transported into the gland packing area and no longer removed during system cleaning. This allows dirt particles to accumulate in this area and/or the multiplication of bacteria. In order to avoid this, bellows made from PTFE or in stainless steel are often used as actuator seals. But with this design solution too, medium can be deposited between the bellows convolutions.
Born from a need for precise and aseptic control valve applications for small volume dosing in the pharmaceuticals, biotechnology and food/beverage industries, GEMÜ has developed a diaphragm globe control valve, the GEMÜ 567 BioStar. The valve allows small volumes to be regulated extremely accurately under aseptic conditions from 80 l/h to 12,500 l/h. Using innovative sealing via GEMÜ PD (Plug Diaphragm) combines the advantages of proven diaphragm valve technology, which has always guaranteed hermetic separation of fluid from the operator, with excellent fluid control characteristics. With the PD design, a PTFE diaphragm has been developed that achieves the controllability of a globe valve and also fulfils the strictest purity requirements. The separation of the area conveying the medium from the actuator is implemented through an FDA-compliant PTFE diaphragm, whilst control is effected via a parabolic plug.
The benefits of the diaphragms and the angle valve body are associated with their cleanability and the cavity-free geometry. This makes the valve a suitable control valve for aseptic areas and a very wide range of control applications. However, it can also be used in other sectors with strict demands on control accuracy and cleanability. All elements of the GEMÜ 567 which come into contact with the media, as well as the valve body and actuator, are made of stainless steel or resistant high-performance thermoplastics. Available with manual, pneumatic and motorised actuators, the GEMÜ 567 BioStar is CIP/SIP capable and can also be integrated into GEMÜ stainless steel multi-port valve blocks.