Rotary Seal with Encapsulated Spring

Series 439: Rotary Seal with Encapsulated Spring

The 439 Series Rotary Seal is a popular seal used in moderate- to high-speed applications that require maximum reliability and long service life. The unique encapsulated spring ensures that the spring remains in place during a blind installation. The main body is strong yet flexible for ease of installation and stability within the groove. The lip force is optimized for the full range of sizes by varying designs of the internal spring, allowing low friction and minimal wear.



Lip force is optimized for a range of sizes by varying designs of the internal spring

Works in a wide range of temperatures

Excellent fluid compatibility

Exceptional abrasion resistance

Available in diameters up to 2100 mm


The 439 series rotary seal is used in industrial rotary applications that require minimum wear and long service life.

Typical Applications

  • Steel and Aluminum Processing
  • Pulp and Paper
  • Pumps and Gear Boxes
  • Marine
  • Wind Energy
  • Bearing Manufacturers

The 439 series rotary seal features high-grade NBR reinforced with elastomer and fabric heel. To suit a variety of applications, the series is also available in higher temperature HNBR and FPM compounds.

Material Code
NBR fabric / garter spring MN139
HNBR fabric / garter spring MN145
FKM or FPM / fabric / garter spring MF24
Temperature MN139

hydraulic oil -30…+100 -22…+212
water oil emulsions (HFA) +5…+60 +41…+140
water-glycol fluids (HFC) -30…+60 -22…+140
polyol esters (HFD) -30…+80 -22…+176
water +5…+100 +41…+212
Speed 15 m/s (50 ft/sec)
Pressure 7.25 bar(105 psi)

Note: for other materials or fluids please contact our engineering department.