Combined Rod Load (Reciprocating Compressor)

The sum of actual gas load (including valve and passage losses) plus inertia loads at the crosshead pin, in the direction of the piston rod. This force varies continuously throughout the revolution of the crankshaft. The term appeared in both the 4th and 5th edition of API-618 with the same definition; however, the 4th edition required that it be calculated every 10 degrees and the 5th edition required that it be calculated every 5 degrees.