Rotary Shaft Seal Inspection
ROTARY SHAFT SEAL
Among the things to look for when inspecting shaft seals is to check for deteriorated or cracked elastomer. This is a telltale sign that heat is an issue and that maybe you are using the wrong elastomer Also by verify that the shaft seal is still in place. A few pumps that had the wrong seal installed when started the vibration and movement caused the seal to come out of the bore and spin on the shaft.
Any oil leaks around the seal should be a red flag to investigate further. Worn seals can cause leakage, plugged breathers or damaged bearings that allow radial motion.
When analyzing any rotary shaft seal failure, look at the seal, shaft and bore. While inspecting the shaft, you typically will see a contact or wear zone where the shaft seal was riding. This will appear as a black scuff-mark where the elastomer has transferred to the shaft.
Remember, in order to keep your shaft seals in good operating order, you must maintain the sump. Cover all seals before painting, keep the oil at the proper level, make sure oil coolers are functioning correctly, and select the right seal design and material. If you are proactive in your approach to rebuilding and installing equipment, you can give your seals and machinery a fighting chance at survival.