Bellows Mechanical Seal

What is a bellows mechanical seal?Bellows Mechanical Seal are a type of mechanical seal where the spring element is a bellows. This eliminates the need for a secondary dynamic seal e.g o-rings. Bellows Mechanical Seals are also known as non-pusher seals as they have a static secondary seal which stays in place against the shaft, sleeve or on the gland of the pump.

What are Bellows Mechanical Seal used for?

A bellows mechanical seal is used where a dynamic seal is deemed unsuitable for the application e.g high temperature medium slurry or high seal hysteresis.

How does a Bellows Mechanical Seal work?

The primary mechanical seal functions exactly the same as a standard mechanical seal except the spring element is now being replaced with a bellows. The friction from the dynamic seal (e.g o-ring) is not a consideration.

What are the bellow types of a Mechanical Seal?

A bellows mechanical seal is available in numerous materials such as;

  • metal bellows mechanical seal where Flowserve have a standardised Hastelloy® alloy C-276.
  • elastomer bellows mechanical seal
  • PTFE bellows mechanical seal
  • Rubber bellows mechanical seal which is mostly used in water industries and Waste Water Treatment plants.

Failure of a bellows mechanical seal is very rare as normally the seal itself will fail before the bellows.

However if a bellows mechanical seal should fail it can be due to several reasons such as; poor wielding, product particulate getting into the bellows and causing the spring element to fail, chemical and/or abrasive attack or over-pressure.

If you have any query around how to install bellow mechanical seals for pumps or have some concerns around the seal failures, why not contact one of our seal specialists below to discuss it in more detail and find out how we can help solve your issues and get your process back up and running reliably again.

Contact our Mechanical Seal Team:

Chris Sheeran (External) –  mob: 087 755 9936

Internal Team

Dave O’Connell – tel: 021 461 7233

Fiona Foley (Service Support) – tel: 021 4617240

Tel: 021 461 7200