What could cause persistent leakage in piston rod packing on a reciprocating steam pump?

Persistent leakage in piston rod packing on a reciprocating steam pump can often be attributed to misalignment of the crosshead guide. When the crosshead is not properly aligned, it may cause uneven wear on the packing material or apply uneven force to the piston rod. This misalignment can increase the likelihood of gaps forming in the packing, allowing steam or fluid to escape, which results in leakage.

Correct alignment is essential for ensuring that the piston rod moves in a straight line throughout its travel, maintaining the integrity of the packing. If the crosshead guide is misaligned, it causes the packing to be under stress, leading to rapid degradation and consequential leakage.

While worn packing material, insufficient lubrication, and incorrect installation can also contribute to leakage, they are not the primary cause in this context. Worn packing would suggest that the material is aged but does not address the immediate issue of leakage originating from a structural misalignment. Insufficient lubrication can lead to friction and increased wear, but again, does not specifically point to a cause affecting the alignment of the moving parts. Incorrect installation might lead to initial problems but would not typically result in persistent leakage unless compounded by ongoing misalignment issues. The focus on misalignment highlights the importance of mechanical precision in maintaining the functionality