The Grundfos CM pump has been created with compactness, flexibility and reliability as its central features. This horizontal multi-stage close-coupled pump is a compact, reliable and quiet pump designed to work in a variety of applications. CM pumps are fitted with mains-operated motors. A Grundfos engineered mechanical shaft seal has been designed to eliminate industry-wide problems with shaft seals sticking where SIC-SIC seal faces are used. The solution builds on both the implementation of a rotation stop on the stationary ring and different surface finishing on both the stationary and rotating rings.