Proven Performance — In-Line Cartridge Design Pumps are backed by over 42 years of Taco experience in design and manufacture of circulators. Tens of thousands are in service. Dependable — Quiet Operation — In-Line Cartridge. Design Pumps offer quiet, dependable pumping power and long-lasting performance. Ideal for heating and/or air conditioning systems requiring high head performance with relatively low volume. Unique Cartridge Design — The Taco “Cartridge” pumps are the first in-line pumps to be specifically designed for hot water service. The unique cartridge design allow operation in systems up tol 300°F. Bearing lubricant is isolated from the effects of the system fluid temperature. The Taco Cartridge pumps are the only in-line pumps having a centrifugal lubrication system. A dip stick is provided to check the oil level and a drain plug is provided to change the oil when necessary.