Shaft Seals – Pressure Resistance Overview.

When evaluating the pressure capabilities of standard shaft seals, it’s important to consider their typical construction: a metal frame, a rubber sealing lip, and a spring-loaded garter spring. These components are designed primarily to prevent leakage of the working fluid under moderate operating conditions.

Below is a table outlining the typical pressure and velocity ratings for various shaft seal types:

Type DrawingPressure avg.
 Pulse Pressure max.
 Maximum Velocity (m/s) Material for rating
 Equivalent Types / Analogs
AS 0,05 MPa / 5 bar 0,05 MPa / 5 bar   NBR WAS, BASL, TC, DGS, RST, CC, RP
ASY 3,5 Bar 7 Bar 9 FPM BABSL, WASY, RST-D
PPS 5 Bar 25 Bar 15 FPM PPS1, PPS2, PPS3
BAHD 120 Bar 170 Bar 2 NBR  
HLPS 150 Bar 200 Bar 1,5 HNBR  

Notes:

  • NBR (Nitrile Rubber) is typically used in general-purpose applications involving oils and grease at moderate temperatures.
  • FPM (Fluorocarbon Rubber / Viton®) is used for high temperature and chemically aggressive environments.
  • HNBR (Hydrogenated Nitrile Rubber) is suitable for high-pressure, high-temperature hydraulic systems.

These ratings are approximate guidelines and may vary based on installation parameters, shaft finish, housing tolerances, and dynamic runout. Always consult the manufacturer's technical data for critical applications.