Hecker® AEGIRA® HN 480

Cartridge seal containing
 two mechanical seals for
conventional installation spaces
according to DIN 24960
Fields of application Design features Application limits
  • chemical industry
  • food industry
  • environmental technology
  • water and sewage technology
  • oil refinery
  • power stations
  • paper industry
  • building machinery
  • cartridge seal with double mechanical seals
  • for conventional installation spaces DIN 24960
  • stationary sealfaces avoid tumbling caused ba misalignments of the cover plate and shaft
  • locking pressure smaller operating pressure allowed (pressureless quench)
  • in case of pressure drop in the locking curcuit both seals stay closed
  • balanced for pressure from the inner and outer side
  • small friction losses
  • seal rings made of solid materials with special design for favourable deflection
  • independant on direction of rotation
  • springs without contact to the sealed fluid
  • small rotating masses, low churning losses
  • exact position guaranteed by solid distance holders
  • easy installation 
  • d1 = 25...100 mm
  • operating pressure p1 max = 25 bar*)
  • locking pressure p3 max = 25 bar*)
  • (delta)p = (p3 - p1) = 1,5...2,5 bar
  • vg = 20 m/s*)
  • T = -40ºC bis + 200ºC**)

    *) dependant on  materials
    **) dependant on the o-ring-material 

 

The seal of the type Hecker AEGIRAâ- HN 480 is a cartridge seal containing two balanced mechanical seals for universal operation in lockingsystems of pumps, agitators and mixers. As a result of the design with a small outer diameter it can be installed in conventional stuffingbox spaces according to DIN 24960. The housing of the cartridge is fixed directly on the cover plate. The main part consists of two stationary mechanical seals back-to-back with identic geometry. Misalignements of the cover plate and the shaft will be egalized by the two seal faces during the installation process.

While running there will be no tumbling motion of the seal face, that would lead to an oscillating axial movement of the o-ring with the result of a damage of the elastomer. The springs are installed in the housing. They do not rotate and have no contact to the fluid to be sealed. Clogging and the obstruction of the moveability is avoided. In the pre­assembled state the housing and the rotor of the cartridge are adjusted with an absolutly exact position by the means of solid distance holders. After fixing the cartridge on the pump housing and on the shaft the distance holders are to be removed. This guarantees an exact position of the parts to each other in the operation period.

The seal rings are balanced for pressurized fluid from the outer side as well as from the inner side. Even in the case of a high pressure the axial force and the friction are reduced. If the pressure of the locking circuit drops below the fluid pressure the sliding faces will stay tight. This enables the operation of the locking circuit with a high pressure as well as a pressureless quenchcircuit. Seal faces and mating rings are made of solid materials. The mating rings are designed with a nearly square profil with a high resistance against deformation influenced by pressure forces and thermal deflections. Especially at the seal rings towards the atmosphere, which are pressurized on the inner side, the design of the shape and the position of the o-rings lead to a favourable deformation. The mating ring will be loaded by the pressure only on its radial face, on its back side it is held by an o-ring. Therefore the deflection caused by the pressure is situated to compensate the thermal deflection partially. This leads to a favourable shape of the gap between the sliding faces. On the product side the o-ring on the back of the mating ring avoids the penetration of the fluid into the gap towards the sleeve. The smooth outer contour of the short rotor may cause only little churning of the sealed fluid. Fibrous and solid parts cannot adhere on the rotor.

The standard of the material combination of the seal rings toward the product is SiC (Q1) for both rings. Towards the atmosphere the sealface made of SiC in combination with a mating ring made of carbon should is recommended.

Seals of the type HN 480 are available for shaft sizes from 25 to 100 mm. They can be used for operating pressures up to 25 bar and sliding velocities up to 20 m/s. Dependant on the material of the o-rings the temperature-range includes –40°C to 200°C.

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