Item Description
1 Seal face
2 Stationary seat
3, 3a, 3b O-Ring
4 Spring
5 Collar
6 Driver
6a Set screw



  • Single pusher-type seal
  • Unbalanced
  • Independent of direction of rotation
  • Super-sinus spring
  • Short installation length, according to EN 12756 (L1KU)


The BT-C8 mechanical seal range is designed for universal application and is ideally suited for standardization. The seal is bi-directional, unaffected by the direction of shaft rotation and is positively driven by set screws. With super-sinus spring. The advantages of this mechanical seal are the easily interchangeable seal faces which permit all material combinations.

Operating range

Shaft diameter:
d1 = 16 … 100 mm (0.79" … 3.94")
Pressure: p1* = 12 bar (16 bar) (174 PSI)
t* = -35 °C … +180 °C (-4 °F … +356 °F)
Sliding velocity: vg = 20 m/s (66 ft/s)

* Dependent on medium, size and material


Seal face:
Silicon carbide (Q1), Aluminium oxide (V)
Carbon graphite resin impregnated (B), Carbon graphite antimony impregnated (A), Silicon carbide (Q1)
NBR (P), EPDM (E), FKM (V), FFKM (K)
Metal parts: CrNiMo steel 1.4401 (G)

Standards and approvals

  • KTW
  • W270
  • ACS
  • WRAS
  • NSF
  • FDA
  • DM 174/04


Seat ring of alternative seats can be supplied with short tail or with pin to block the seat and prevent seat rotation.