Use cases ·

Types of mechanical seals, carbon and graphite seal faces

Mechanical seals are very important elements in industry because they keep machines running and prevent fluid leakage, which can put processes, installations and even personnel at risk. Choosing the right seal is of vital importance. In the industry there are different types of mechanical seals according to their characteristics, construction, applications, among other elements.

Types of mechanical seals, carbon and graphite seal faces

Mechanical seals are very important elements in industry because they keep machines running and prevent fluid leakage, which can endanger processes, installations and even personnel. Choosing the right seal is of vital importance. In the industry there are different types of mechanical seals according to their characteristics, construction, applications, among other elements.

We can classify mechanical seals in four categories based on their operation, characteristics, parts that compose them and then the types of mechanical seals that exist.

Conventional seals

Conventional types of mechanical seals are used in devices or applications that are not designed to have mechanical seals. These types of seals are very standardized, as they are intended to be replacements or part of modifications to equipment, such as pumps.

Balanced and unbalanced seals

Hydraulically balanced seals have the diameters of their faces reduced according to the diameter of the shaft where they are installed, thus reducing the pressure load of the pumped fluid on each face. These mechanical seals can be used when dealing with very high pressures or certain types of fluids.

On the other hand, unbalanced seals receive the full force of the hydraulic pressure on both faces, in addition to the spring pressure.

Dynamic or thrust and static or non-thrust seals

Dynamic seals feature an O-ring that moves axially on the shaft by one or two springs that apply force to the seal faces, while compensating for wear and absorbing shaft misalignment.

Non-thrust seals, on the other hand, do not have O-rings, but are stationary but have a bellows that moves to perform their sealing functions.

Cartridge seals

These are self-contained and are already assembled by default. Their installation does not require a lot of time and process investment, making them a great option for shafts without ideal alignment or with the presence of vibrations.

Split seals

Split mechanical seals are mainly used on large shafts, consisting of two parts that are joined together to give a better grip on the shaft. This type of mechanical seals has many applications in addition to solving major problems, such as seal leakage, without the need to disassemble the equipment.

Types of mechanical seals by materials

  • Graphite
  • Carbon - Graphite, electrographite, electrographite
  • Silicon carbide, tungsten carbide
  • Alumina - Ceramic
  • Graphite impregnated in resin and antimony
  • PTFE