What are mechanical seals?

Know more about Mechanical Seals

Mechanical seals are the most effective technique which prevents the leakage of the fluids in pumps. The basic concept behind mechanical seals is sealing the rotating part of the shaft against the stationary component of the pump.

Types of Mechanical Seals

The mechanical seals manufacturers in India produce several types and arrangements of mechanical seals which are used for centrifugal pumps. The mechanical seal suppliers in India regularly supply different types of mechanical seals and the most used ones are as below.

  • Pusher Mechanical Seals

The pusher type of mechanical seals moves axially along the rotating shaft or the sleeve to maintain the contact with the faces of the seal. This feature helps compensate the wearing that may occur at the seal face, and wobbling due to misalignment.

Commonly used seals are the pusher types of mechanical seals. Also, they are less expensive and are easily available in the market in wide range of designs and sizes. The only disadvantage of these seals is that they tend to hang up and sometimes trouble the shaft.

  • Unbalanced Mechanical Seals

The unbalanced types of mechanical seals are used under severe conditions. This means where there are vibrations, misalignment of the shaft, and the problem of the cavitation of the fluid. These mechanical seals are less expensive, are highly stable and allow lesser leakage of the fluids.

But the only problem is that these seals can operate only under low pressure range. If the force of the fluid surpasses certain limits the lubricating film between the faces squeezes out and the seal fails.

  • Conventional Mechanical Seals

These are relatively simple mechanical seals that should be properly set. It should be aligned on the shaft or the sleeve of the pump.

  • Non-pusher Mechanical Seals

To maintain their contact with their faces the non-pushertype of mechanical seals doesn’t have to be moved axially. These seals can work under high pressure applications and low temperature. The bellows used in these seals should be advanced so that they can work under the corrosive environments.

  • Balanced Mechanical seals

The balanced mechanical seals can sustain higher pressures across the faces. Therefore, they generate lesser heat. They are suitable for handling liquids that have low lubricating capacity and hydrocarbons that have high vapour pressure.

  • Cartridge Mechanical Seals

The main advantage of the cartridge mechanical seals is that they require simple setting during the installation as required by the conventional seal. Thus, it helps reducing faults associated with seal setting and lessens the maintenance required.


Finally, above mentioned information might be helpful to choose the type of mechanical seal you need according to the surrounding and settings where it needs to be installed.

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