How Many Types of Mechanical Seals Are There?

How Many Types of Mechanical Seals Are There?

How Many Types of Mechanical Seals Are There?

04 May 2020

How Many Types of Mechanical Seals Are There?
Mechanical seals are distinct from other types of seals because it involves a rotating part, a stationary part and a spring. The seal is the interface between the moving and stationary parts. Sealing the junction of a moving and a stationary part is a challenge, to say the least, and the spring is there to ensure adequate pressure on the parts to maintain the seal despite the movement. To be effective, mechanical seals must fit the specific application where they are used. Those applications can vary considerably. Mechanical seals must have the precise measurements and be made of appropriate materials to withstand whatever temperature extremes or chemicals are involved, or the seal will fail. We can group seals into general types, which raises the question of how many types of mechanical seals there are.

8 Types of Component Mechanical Seals

Seals and gaskets are sometimes custom-made to service unique applications, but we can group most seals that prevent leakage at the interface of a moving part and a stationary part into eight main types of component mechanical seals.

  1. Wave Spring Mechanical Seals: Principally used for liquids of high viscosity, wave spring mechanical seals are popular for pharmaceutical, dairy, brewery and food processing applications. They are often fitted to the shaft with grub screws and in the case of high viscosity media would also have stationaries with anti-rotation pins. Some designs are specially constructed to work in shallow, confined seal housings.
  2. Water Pump Seals: Because water is such a poor lubricant of seal faces, it is critical that water pump seals use excellent materials for applications such as shower pumps, irrigation, heating systems, swimming pools and spas.
  3. Bellows Mechanical Seals: Compact, versatile, extremely reliable seals suitable for a wide range of applications. Available with either O Ring Mounted or Boot mounted Stationaries in DIN and Non-Din sizes. Recommended for media containing solids and are widely used in Pumps, mixers, compressors etc.
  4. Diaphragm Seals: Featuring parallel springs, diaphragm seals are used in very diverse applications including agitators, compressors, mixers, pumps and other rotary shaft equipment. . The diaphragm in the rotary head rotary seals on the shaft so they are not affected by rotational direction.
  5. Balanced Diaphragm Seals: Similar to Diaphragm seals but are also hydraulically balanced to reduce heat and friction at the seal interface, an innovative patented design protects against seal failure in applications where thin metal drive components are prone to cut into the retainer.
  6. Conical Mechanical Seals: This is an extremely versatile and popular mechanical seal. Available in a wide range of materials to suit a variety of environments, they are robust and durable. However these seals are rotation dependent and come with either left hand or right hand springs.
  7. Parallel Mechanical Seals: Parallel seals are a heavy duty single spring seal. They can use different methods of providing the face to the seal and can be supplied with either left- or right-hand wound springs. A good general-purpose seal, they are used in marine pumps, waste-water, pulp and paper and textile applications as well as refrigeration compressors.
  8. Multi Spring Seals: Proven effective design, PTFE wedge styles are often used in chemical the chemical industry for arduous applications such as corrosive process fluids.

With so many types of mechanical seals, it can be difficult to know if you are choosing the absolute best one for your equipment. If you are unsure which type of mechanical seal is the best for your specific application, don’t hesitate to get in touch. Our experts can review how many types of mechanical seals would work in the specific application and which ones are best suited for it.

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