The total length of stroke in a reciprocating steam pump can be adjusted by __________.

Correct Answer: Option A — changing the setting of the tappet collars on the pilot valve operating rod

Reciprocating steam pumps utilize a pilot valve to control the main steam valve. The tappet collars on the operating rod determine the point at which the pilot valve shifts. Adjusting these collars changes the timing of the steam reversal, thereby directly controlling the total length of the piston stroke.