7 Signs of Mechanical Seal Failure

Grooves or Notches on Seal Face

Deep, concentric grooves or notches on the seal face are one of the most common signs of mechanical seal damage. These grooves can be caused by abrasive particles in the process fluid, shaft vibration, or contact with the rotating seal components during operation. Over time, the grooves will compromise the integrity of the seal face, leading to leakage and premature failure.

Uneven Wear Track

An uneven wear pattern on the seal face or seal ring can indicate misalignment, shaft deflection, or bearing issues. If the wear track is deeper on one side than the other, it suggests that the seal is not maintaining consistent contact with the mating surface. This uneven wear can be caused by improper installation, shaft vibration, or excessive axial movement of the pump shaft.

Fractured or Cracked Seal Face

A fractured or cracked seal face is a serious issue that requires immediate attention. Thermal shock, sudden changes in fluid temperature, or excessive pressure can cause the brittle seal face material to crack or shatter. Seal face fractures can also result from mechanical shock during installation or start-up. Once the seal face is compromised, the sealing function is lost, leading to significant fluid leakage and potential equipment damage.

Chips, Cracks in Seal Ring

Similar to seal face damage, chips or cracks in the seal ring can compromise the sealing performance and lead to premature failure. Mechanical shock, thermal stress, or debris in the process fluid can cause the seal ring to chip or crack. A damaged seal ring cannot maintain a tight seal against the seal face, resulting in fluid leakage and reduced pump efficiency.

Squealing or Popping Sound

Unusual noises coming from the seal area, such as squealing, squeaking, or popping sounds, can indicate a problem with the mechanical seal. These sounds may be caused by dry running conditions, insufficient lubrication, or contact between the rotating and stationary seal components. Squealing noises can also result from the collapse of vapor bubbles in the fluid, a phenomenon known as cavitation.

Cracked or Chipped Seal Ring

A cracked or chipped seal ring can compromise the sealing performance and lead to premature failure. This damage can be caused by mechanical shock during installation or operation, thermal stress, or abrasive particles in the process fluid. A damaged seal ring cannot maintain a tight seal against the mating seal face, resulting in fluid leakage and reduced pump efficiency.

Accumulation of Carbon Dust on the outside of the Seal

An accumulation of fine carbon dust around the outside of the mechanical seal is a sign of seal wear and potential failure. As the carbon seal faces rub against each other during operation, they slowly wear away, generating carbon dust. If this dust is visible on the outside of the seal gland or stuffing box, it indicates that the seal faces are wearing excessively, and the sealing performance may be compromised.

FAQs

How Long Should a Mechanical Seal Last?

On average, a well-maintained mechanical seal in a typical industrial application can last 2-5 years before requiring replacement.