Breweries need pumps to convey water, mash, wort, beer, cleaning and cooling agents, and a number of other liquids produced or required in the process of brewing. Mechanical seals are being used to seal an increasing proportion of these pumps – almost 100 % in many breweries. With the necessary pump pressures generally lying below 10 bar, the majority of these seals are single, unbalanced mechanical seals. Mechanical seals dependent on the direction of rotation and with the face material pairing WC/WC are mostly chosen to seal media containing solids such as barm, mash, wort and beer with kieselguhr (filtering agent). For solids-free media such as e.g. beer and alcohol water, the preferred face material pairing is cast Cr-steel/ carbon graphite. For the secondary seals use is made of EP rubber (e.g. with alcohol water and hot water) as well as fluorocarbon rubber (e.g. Viton^®). The facilities are cleaned and sterilized by various processes, requiring a corresponding variety of chemicals. The face material pairing aluminium oxide/ carbon graphite has proven successful, as has WC/WC with media inclined to crystallization. Secondary seals are made of fluoroelastomer double-covered with PTFE. If the facility employs a CIP process, seal faces made of binder-free metal carbides or metal oxides (e.g. S-SiC) and secondary seals made of PTFE are employed, because normal elastomers are not permanently resistant.