Abstract: A strainer assembly is provided for a heat exchanger of the type including at least one heat transfer tube having an inlet end opening outwardly through a tube sheet or tube end plate. The strainer assembly includes an elongated tubular body having first and second end portions and a mid-length outwardly projecting circumferential flange on opposite sides of which the first and second end portions are disposed. The first end portion of the tubular body is open and tightly frictionally telescoped within the inlet end of the heat exchange tube and the second end portion of the body includes an end wall defining spaced apart first openings formed therethrough. The second tubular body end also includes a plurality of circumferentially and longitudinally spaced second openings formed therethrough, the first and second openings being of a predetermined size.