Question 420General Subjects - Assistant Engineer

The correct answer is A) changing the setting of the tappet collars on the pilot valve operating rod. The total length of stroke in a reciprocating steam pump can be adjusted by changing the setting of the tappet collars on the pilot valve operating rod. This adjusts the travel of the pilot valve, which in turn controls the length of the main steam valve's opening and closing, and thus the total stroke length of the reciprocating pump. The other options are incorrect because: B) variations in the throttle adjustment only control the amount of steam delivered to the pump, not the stroke length; C) twisting the stay rod does not directly affect the pump's stroke length; and D) changing the number of packing rings around the piston rod also does not directly control the stroke length.