Dry Seals


The shaft seal type SPE is a single-acting bidirectional mechanical seal. It was specially designed for sealing against abrasive products and is used for flooded side entering applications. The seal rings are surrounded, lubricated and cooled by the product. The hydraulic design and the preload of the springs are arranged in such a way that the seal gap of the highly wear-resistant pair of seal rings (Silicon carbide) is reliably lubricated. This makes any hydraulic installation superfluous, i.e. in the plant no additional seal liquid supply systems need be used. The temperature in the seal gap is so low that no evaporation of the fluid in the seal gap occurs. Springs, drive pin and o-rings are protected against caking.


The SPE is the most used mechanical seal in FGD-agitators worldwide. Special metallic materials for product-wetted components give reliable protection against corrosion, also in the use of aggressive media. If highly aggressive media are used and the highest safety conditions are necessary, the product-wetted components can be manufactured in a special plastic which is highly corrosion-proved.

The main areas of application are:

  • Flue gas desulfurization (FGD)
  • Hydrometallurgy
  • Pharmacy
  • Biotechnology


Housing: Stainless steel 
Product-wetted parts: Stainless steel, Hastelloy, Titanium, special materials
Seal rings: Carbon, Silicon Carbide, Tungsten Carbide, etc
O-rings: Viton, EPDM, Perfluor elastomers, special elastic materials
FDA-approval: Possible for all product-wetted parts

Application Limits :

Vessel pressure: Vacuum ...16 bar (abs.) 
Vessel temperature:-50 … +200° C
Shaft size: 40 ... 300 mm
Sliding speed: 5 m/s

Quality :

SEAL PROOF is supplied ready for installation as a cartridge unit. Prior to delivery every mechanical seal is dynamically tested under process conditions according to an internal QM System and receives a test certificate. The seal type SPE is designed to optimum GMP requirements and is TÜV certified for applications in hazardous.