scope:

These standards cover the sanitary aspects of disc-type valves having a one- or two-piece body and disc with the disc rotating between the closed and open positions, as used on tanks or vessels that hold the product or solutions and as installed in product and solution pipelines. The stem that rotates the disc does not penetrate the seal face or seal seat insert of the valve. The disc-type valve begins at the product inlet connection and ends at the product outlet connection. These Standards do not include butterfly-type valves which may use two- or threepiece bodies and gaskets as sandwich seals and seal faces in combination with a disc and in which the stem penetrates the elastomer seal.

In order to conform to this 3-A Sanitary Standard, disc-type valves shall conform to the following design, material, and fabrication criteria, and applicable documents referenced herein.