The Grundfos TPD 100-410/4-A-F-A-BAQE is a three phase, twin head in-line circulator pump with 100mm flanged connections. The Grundfos TPD are a range of twin-head, vertical in-line pumps commonly used as heating circulator pumps in commercial building services, industrial processes and water supply. Each TPD pump has two reliable, high-efficiency, IE3-rated motors and are electro-coated to prevent corrosion.