Mechanical Seals

Mechanical seals are used to prevent liquid from leaking out of pumps, between the rotating shaft and the pump casing.

Earlier pump models may use mechanical packing (otherwise known as Gland Packing).

If you’re wondering why your mechanical seals keep failing, then this blog post can assist you in advising 5 possible reasons as to why this may be occurring and how to overcome the issue of failing mechanical seals.

1.The pump has been ‘run dry’

Not only does this have an impact on mechanical seals, but this can affect other areas of the pump such as the impeller. Running pumps dry can cause the impeller to melt along the shaft, causing the impeller to seize onto the shaft.

2. Heat caused the o-rings to deteriorate

3. The seal materials were attacked by the fluid being sealed

4. There is an operator error

Skipping initial start-up procedures are a big factor when it comes to mechanical seal failure. Improperly starting the pump can cause the motor to trip and the shaft to twist causing undesirable orbit movement.

5. The wrong seal has been installed or the seal has been installed incorrectly

So now you know what might be causing Mechanical Seal failure, but what can you do to avoid failure?

1. Choose the correct seal

Lack of knowledge and information will only cause obstacles in the seal selection process. Before deciding on a seal, you should carefully consider the application and operating conditions. It is highly likely that you may need to speak to a specialist to ensure the information yo have obtained is accurate, or even to obtain the information required.

2. Properly install the seal

Mechanical seal installations should be performed using the specific steps outlined by the manufacturer, taking care to avoid damage to the seal faces and / or O-rings.

Seeking assistance from a specialist to do this is also likely to be necessary.

3. Prevent excess heat generation

Excessive heat generation between seal faces can drastically reduce seal life. Dry running should be avoided at all costs. Dry running typically occurs when a pump is flooded or the seal chamber is incorrectly vented before pump start-up.

4. Maintain proper storage conditions

Mechanical seals are composed of many unique parts and a variety of materials. Because of the diverse properties and precise nature of these components, it is imperative to understand how long a seal can be stored safely without compromising function.

Should you require any further advice on how best to store a seal, or need assistance installing mechanical seals, get in touch.