KSB has developed a new double mechanical seal in tandem arrangement, the 4STQ, which is especially suited to the particular requirements of dry-installed and wet-installed waste water pumps. During its development, KSB’s engineers worked to ensure that its installation and removal is as straightforward as possible. Assembly fixtures and fastening bolts are not required, and the seal’s modular design minimizes downtime during maintenance inspections as well as preventing faulty reassembly.

A multi-spring arrangement provides required pre-loading for the primary rings themselves. The multiple springs are located outside the fluid handled in the oil reservoir so the individual springs are protected from contamination. The seal installation space and the mechanical seal are optimally matched so the seal faces are exposed to minimal wear and the sealing elements have long service lives.

The primary rings are made of silicon carbide as standard, with tungsten carbide also available. All metal components are manufactured from corrosion-resistant stainless steels and FKM elastomers are used for the O-rings. The new 4STQ is suitable for all operating conditions permitted for the pump on which it is fitted.