So-called elastomer bellows seals are frequently used in wastewater plants and fresh water supply systems. Due to the neutral pH value, EPDM materials with a resin impregnated carbon seal ring against silicon carbide can be used here. The most commonly used seal is the EB02, although for solids-laden effluents an O-ring encapsulated component seal is preferred. In this case the S130, which prevents or minimizes solids deposition in the spring area (group springing) due to the encapsulated design of the O-rings. For large conveying systems, split mechanical seals are also used. For critical supply systems, double mechanical seals with blocking systems such as the TS-9-16 are often used.