Rotary Pumps
Rotary pumps are powered by a motor (usually made by RPM) and are an integral parts of providing the right pressure for espresso extraction. They are adjustable via the screw fitting on its side and for optimal performance a water filter and pressure reduction valve should be installed prior to the pump. Commonly rotary pumps are generally made by either Procon or Fluidotec, although other brands are available.
The main difference between pumps is on the connection to the motor, generally they come in clamp ring 700008, two-bolt 630177 and three-bolt 700009.
Pumps using bolt connections need connectors between the pump and motor, however clamp ring pumps connect directly tot he motor.