Abstract: A method for detecting the occurrence of surge in a centrifugal compressor includes the step of calculating a time rate of change of a discharge pressure of the fluid discharged from the compressor. In one preferred embodiment, the time rate of change of the discharge pressure is calculated by initially setting PREV PRESS and RATE PRESS variables equal to zero (0), and commencing a RATE PRESS subroutine having a time limit for cycling therethrough. The RATE PRESS subroutine includes the steps of obtaining a discharge pressure reading for the fluid discharged from the compressor, subtracting the discharge pressure reading from the PREV PRESS variable to establish the RATE PRESS variable, and resetting the PREV PRESS variable equal to the value of the discharge pressure reading. After the RATE PRESS variable has been determined, the RATE PRESS is compared with an acceptable set time point rate of change for the discharge pressure.

Abstract: A lifting bail adapted to be made integral with a machine having a center of gravity includes a lift eye plate located substantially near the machine center of gravity, a first locator member having openings for locating the lift eye plate substantially near the machine center of gravity and a second locator member having openings for locating the lift eye plates substantially near the machine center of gravity. The openings for locating the lift eye plate relative to the center of gravity are oriented along the first and second locator members so that when the first and second locator members are made integral with the machine, the openings are aligned and thereby provide the location for the lift eye plates substantially near the machine center of gravity.