a portable flange facer may be used to machine flange faces without removing the pipe from its installation thereby avoiding extensive disassembly and downtime . a stationary spindle , mounted centrally within the pipe bore , provides a structure about which a main body rotates . a motor , mounted upon the main body , and a gear means , coupling the motor to the stationary spindle , are used to rotate the main body about the spindle . a cutting element , mounted upon a turning bar slidable within the main body , may be moved radially inwardly and outwardly by manual or automatic means . the flange facer may be used to resurface a flange face or to form circular grooves therein .