The valve is a special double-seat valve in which the leakage chamber is designed as a sterile chamber and hermetically separated from the environment by two side valves. The sealing properties of the stem diaphragm make it possible to increase the shelf life of milk-based and lactic acid fermented products.
If manufacturers adapt the process chain accordingly, GEA said, D-tec enables them to achieve the desired shelf life of a product even with fewer preservatives. The diaphragms are made of a thermoplastic that is more flexible than stainless steel.
With the double-chamber valve D/DV, GEA said it has completed its valve program, so that customers can now fully equip their production processes with D-tec.
Product manager Pascal Bär, who looks after the aseptic valves at GEA, said, "Equipping the interfaces in process plants with as few valve types as possible is often a decisive criterion for our customers. The more different valve series have to correspond, the more complex the spare parts handling and warehousing becomes."
With the D-tec double-chamber valve, GEA now offers aseptic valves for both hygiene classes "Aseptic" and "UltraClean", which are tailored to the special conditions of the respective applications.
"Aseptomag - our stainless steel bellows technology - is the premium class of aseptic valve technology, which we recommend for highly sensitive products such as baby food and UHT milk. These require uncompromising aseptic execution of the processes and components," Bär said.
"But a large proportion of the beverages produced by our customers are not conveyed under aseptic conditions but fall into the second highest hygiene level according to the VDMA guideline, which is hygiene class IV, UltraClean. Our new double-chamber valve in the D-tec line is precisely tailored to the process requirements of this hygiene class."
According to GEA, D-tec is ideally suited for products such as fruit yogurt and ESL milk, where product parameters such as pH value, cold chain, storage and shelf life play a decisive role.
The hermetically sealed D-tec stem diaphragm offers a higher contamination protection against the atmosphere and thus ensures the microbial stability of the product throughout the entire process. The diaphragms are made of a thermoplastic which is more flexible than stainless steel. For example, it can compensate for pressure hammers and, to a certain extent, forgive process failures, says Bär.
The D/DV double-chamber valve is based on the VARIVENT modular system, which allows the valve to be configured according to the process conditions. Characteristic of this double-seat valve are the two diaphragms that hermetically seal the interior of the product from the atmosphere. It is currently available in nominal sizes DN 40 to DN 80 and OD 1.5" to OD 3". The nominal sizes DN 100 and OD 4" will follow shortly.
The valve seat can be soft- or hard-sealed. In addition, D-tec double-chamber valves can be operated with one, two or three T.VIS control heads of various designs. GEA D-tec D/DV complies with all common industrial standards.