While on watch, you notice that a significant amount of water is flowing out of the packing box from a centrifugal salt water pump which had been recently overhauled. You tighten the packing gland evenly by nearly a half inch, yet the amount of water output from the packing box does not diminish. You should __________.
• Centrifugal pump stuffing box/packing box operation and normal leakage requirements for cooling and lubrication • Effects of over-tightening packing glands on shaft sleeves and pump performance • Purpose of any sealing water line or lantern ring in a salt water pump packing box
• What is the normal purpose of a small, steady leakage from the packing box on a centrifugal pump? Would you ever want to stop it completely? • If tightening the gland by a large amount does not change the leakage, what might that tell you about the condition or placement of the packing inside the box? • What potential damage can occur to the shaft sleeve or packing if you continue tightening the gland aggressively to try to stop the leak?
• Review why some leakage is required for packing lubrication and cooling in centrifugal pumps • Consider what a sudden large leakage after overhaul might indicate about the packing installation (e.g., missing rings, wrong size, worn sleeve) instead of just loose gland nuts • Verify whether closing sealing or flushing water lines is an appropriate way to control leakage, or whether that could starve the packing and cause overheating
No comments yet
Be the first to share your thoughts!