The sanitary versions of the rotary valves manufactured by Coperion GmbH, Weingarten/Germany, have now been approved by the United States Department of Agriculture (USDA) following certification in compliance with the USDA Dairy Grading Branch.
Already designed in accordance with the engineering and design guidelines of the EHEDG (European Hygienic Engineering & Design Group), these hygienic rotary valves - ZRD discharge valves and ZXD blow-through valves - now also meet the current, strict requirements governing application in the USA.
The valves can be used in the food, pharmaceuticals and chemical industries for applications demanding even the highest degree of hygiene and cleanliness. In addition, they are distinguished by their extreme reliability in operation. As these rotary valves can be readily inspected and also cleaned quickly and thoroughly, they are ideal for applications involving frequent changeovers from one product to another and/or for the processing of products with adhesive tendencies.
The sanitary versions of the ZRD and ZXD series of rotary valves are used in pneumatic conveying systems and for the discharge of powdered and granular materials. The rounded base of the rotor chamber permits easy discharge of the product. The rotary valves are smoothsurfaced, free from dead spots and manufactured completely in stainless steel. They can also be cleaned wet (COP = cleaning out of place). All surfaces that come into contact with the product are polished to an average roughness of Ra = 0.8 ìm, which means that deposits of product or washing agent residues can be avoided virtually completely.
The certified versions of the ZRD and ZXD series of rotary valves are equipped with the innovative and service-proven FXS (Full Access System), which enables easy withdrawal of the rotor, as both side covers can be swung out through an angle of more than 90°, making the interior of the rotary valve fully accessible. The withdrawn rotor can then be readily detached from the side cover. A completely new type of sealing cartridge (patent pending) for the shaft seal is located in the side cover. A gas purging device located upstream of the seal prevents ingress of the conveyed product into the shaft seal and bearings. For inspection and maintenance purposes the sealing cartridge can be withdrawn from the side cover with the aid of a simple hand tool and then dismantled into its component parts.
The USDA-approved rotary valves are fitted with FDA-compliant sealing materials as standard. In order to prevent microbiological growth, slots and gaps have been reduced to the technically necessary minimum; unavoidable slots and/or gaps have been flush-sealed, both on the inside and on the outside of the valve. Consequently, the hygienic versions of the ZRD and ZXD series of rotary valves combine optimum accessibility for cleaning and inspection with the highest security against contamination, thus ensuring extreme reliability in operation.