Prevent Mechanical Seal Failure

Proper pump alignment is essential when installing mechanical seals. Fasteners should be secured evenly.

A mechanical seal consists of two primary components.

One is stationary and the other rotates against it to achieve a seal. There are several types of mechanical seals, ranging from simple single-spring designs to considerably more complex cartridge seals. The design, arrangement, and materials of construction are essentially determined by the pressure, temperature, speed of rotation, and product being sealed (the product media).

Mechanical seal failure is the greatest cause of pump downtime. Understanding how seals work and proper handling is beneficial for prolonging the lifespan of the seal and overall health of the machine. Here are some tips that will help you properly install and maintain mechanical seals, resulting in increased reliability.

Mechanical seals should be treated like bearings and kept free of dust and debris.

Proper handling and cleanliness

• Treat mechanical seals like bearings.
• Follow instructions from the manufacturer.
• Use clean hands or gloves that are free of any grease or oil.
• Keep seals away from any dust, debris, or lint.
• Avoid dropping seals. Dropped seals generally need to be replaced. 

Installation and assembly

• Always follow the installation instructions.
• Never install on a misaligned pump.
• Make sure all moving parts are properly lubricated.
• Handle the seal with care.
• Make sure fasteners are evenly secured and not over tightened.

Extending lifespan

Mechanical seals can last 2 to 10 years. In addition to proper handling and cleanliness, the following factors can have a negative impact on the lifespan of a seal:

• heat generation
• letting a pump run dry
• too much vibration
• hammering couplings
• using the wrong type of seal. EP

Information for this article was provided by ACOEM Vibralign, Richmond, VA. For more information about mechanical seals, pump-shaft alignment, and precision-maintenance training, visit vibralign.com. Click here to download a poster about mechanical seal fundamentals.