Item Description
1 Seal face
2, 3, 6, 8, 12, 13 O-Ring
4 Spring
5 Adapter
7 Housing
9, 15 HSH cap screw
10 Seat
11 Shaft sleeve
14 Clamp sleeve
A Seal gas supply



  • Single seal with double seal function
  • Non-contacting from static to high speed condition
  • Balanced
  • Bi-directional
  • Stationary multiple springs


  • Wear-free and contact-free operation
  • Prevents the ingress of foreign particles

Operating range

Pressure: p = 5 bar (73 PSI)
t = -20 °C … +200 °C (-4 °F … +392 °F)
Sliding velocity: vg = 60 m/s (197 ft/s)


Seal face: High-density carbon graphite
Seat: Ductile stainless steel with TiN-coating or silicon carbide
Secondary seals: FKM
Metal parts: CrNiMo steel


Seals from the NF941 series are used in screw compressors for special applications. They are hybrid seals that seal both aerostatically and aerodynamically. The separation gas is routed through holes in the stationary seal ring directly between the seal faces, while the lift-off is caused by specially designed gas grooves. API 692 compliant.

Dimensions on request.