Question 410General Subjects - Assistant Engineer

The correct answer is D) misalignment of the crosshead guide. When the piston rod packing persists in leaking on a reciprocating steam pump, the most likely cause is misalignment of the crosshead guide. The crosshead guide is responsible for maintaining the proper alignment of the piston rod, and if it becomes misaligned, it can cause excessive wear and leakage in the piston rod packing. The other options are not directly related to the issue of persistent piston rod packing leakage. A loose tappet collar, an open snifter valve, or clogged suction strainers may cause other problems in the steam pump, but they are not the primary causes of piston rod packing leakage due to misalignment.