Method of manufacturing an annular slit restrictor using a shrink fit operation

A method of manufacturing an annular slit restrictor comprising:

• forming to predetermined accurate radial dimensions an annular plug having radially projecting spaced end walls forming a recessed annular surface therebetween,
• forming to a predetermined accurate lesser radial dimension than that of said end walls, an annular hole in a flow control body, said flow control body including an inlet port and an outlet port,
• heating said flow control body to increase the radial of the annular hole such that said plug is insertable therein,
• inserting said annular plug into said radially increased annular hole, and
• allowing said flow control body to cool, thereby forming a shrink fit between said annular plug and said annular hole, where
• said spaced end walls and adjacent wall surfaces of said annular hole form contact regions which maintain said annular plug and said annular hole in coaxial alignment,
• said recessed annular surface between said contact region forms a concentric annular slit passage,
• said inlet port extends from the outer surface of said flow control body into said slit passage, and
• said output port extends from said slit passage to the outer surface of said control body.