PTFE Rotary Shaft Seals
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Rotary shaft seals with PTFE sealing lips are sealing elements -ready for assembly - which produce the desired sealing effect through radial contact pressure on the shaft. Sealing performance in the receiving hole is achieved by compression fit according to ISO 16589-1. Radial seals with PTFE sealing lips are ideally suited for sealing rotating shafts. Benefits • Outstanding chemical resistance to corrosive media • Suitable for applications with high thermal loads from -60 °C to +200°C • Suitable for use in low-lube and oil-free conditions • Suitable even for use with unhardened shafts •...

Fields of Application Shaft seals with PTFE sealing lips are suitable for sealing applications involving the following media: • Mineral-based and synthetic lubricants • Pharmaceutical products and foodstuffs (FDA recommendations for certain PTFE compounds) • Chemical waste water and wash water • Corrosive, fluid and gaseous media • Powders and granulates • Coolant and lubricant fluids • Water and steam • Resins, glues and pastes • Air/oxygen (BAM tests for certain PTFE compounds • Heat transfer fluids (oils) Typical Applications • Rotary compressors • Screw-type compressors •...

Shaft seal in a radial-flow fan with nitrogen scavenging, type HN 2390. Shaft seal in a rotary compressor with oil drainage, type HN 2390. Shaft seal in a spindle boring head type HN 2390, friction-optimized. Shaft Seal Design and Action Principle Housing Secondary Seal PTFE Sealing Lip Housing Secondary Seal PTFE Sealing Lip with protection lip Housing Materials Standard: Special versions: Free-cutting steel Mild steel (unalloyed sheet metal for deep drawing) Aluminum Secondary Seal The following materials are used for the secondary seal between the PTFE lip and the housing: Standard:...

Other Special Versions Type HN 2390 Stock List Designation example: rotary shaft seal with PTFE sealing lip for shaft diameter d1 = 75, locating hole d2 = 100 and width w = 10: RWDR HN 2390 75 x 100 x 10 Standard Thanks to its high wear and pressure resistance this standard design is suitable for a wide range of applications, such as pumps, blowers and compressors. Sealing lip compound: • PTFE compound HS 21037 Design features: • Single lip • Reinforced sealing lip • Lip is effectively supported to resist deformation under pressure Properties: • Good sealing performance with pressurized...

Other Special Versions Type HN 2390 Dual lip, rotating in same direction, with or without hydrodynamic return feed spiral groove, good seal­ ing performance, higher operational reliability, e.g. for pumps, screw-type and rotating compressors. Friction-Optimized Special Type Stock List Vis-à-vis the standard version of Designation example: rotary shaft seal with PTFE sealing lip for special type has a significantly shaft diameter d1 = 70, locating lower coefficient of friction. hole d2 = 78 and width w = 6: RWDR HN 2390 Special Type, Friction-Optimized 70 x 78 x 6 Sealing lip compound: •...

Stock List Special Type, Friction-Optimized Standard version for pressureless Designation example: rotary shaft applications and/or pressures seal with PTFE sealing lip for shaft centrifugal machines and blowers. slightly above atmospheric. This ver- sion features a highly flexible seal- lip. Suitable applications include d1 mm 10 tools and pumps. 12 15 18 Standard compound: 20 • PTFE-compound HS 21059 25 30 35 Design features: 35 • Single-part sealing and protective 40 40 lip 45 • Sealing lip with wear protection 48 • Low radial pre-loading of sealing lip 50 55 60 Properties: 65 • Suitable...

Hydrodynamic Return Feed Spiral Groove In case of higher sealing performance requirements to be met by PTFE rotary shaft seals we recommend a spiral groove for hydrodynamic return feed either on the shaft surface or in the sealing lip. In this case, only one rotational direction of the shaft is permissible. Return Feed Spiral Groove in the Return Feed Spiral Groove in the Shaft Surface/Protection Sleeve The hydrodynamic return feed spiral The hydrodynamic return feed spiral groove should have the following groove is worked into the PTFE sealing lip. To prevent dirt from be­ ing carried into...

Long-Term Wear in Dry-Running (Oil-Free) Conditions(2) Test conditions: Test atmosphere: air T =100°C v = 4 m/s p = 0.42 N/mm2 Rz = 2 pm Test period: 100 h unfilled fiber

Power Losses and Friction Torques Type HN 2390 standard and HN 2390 special, Dynamic friction torque (2) Type HN 2390 special, friction-optimized, Test conditions: Dimensions: 15 x 30 x 7, PTFE compound HS 21037, dynamisches Reibmoment Temperature = room temperature/self-heating Verlustleistung HN 2390 HS 21037 Sealing lip compound: Standard und HN 2390 Sondertype Shaft diameter: Surface roughness of shaft: Dynamic friction torque [Nm] 0,06 Pressure stages Dichtlippe 1 mm Stärke Dichtlippe Lip thickness 1 mm 0,7 mm Stärke Rotary speed [1/min] HN 2390 (reibungsoptimiert) Radial force (2) The...

Design of Locating Hole Contact Surface PTFE shaft seals may be used on both hard and soft contact surfaces. Relevant criteria are the sealing lip compound, pressure conditions and peripheral speeds. Generally, hard contact surfaces are recommended. Hardened steel is the most commonly used shaft material. Compared to other shaft materials and coatings, the use of hardened steel achieves very good service life of the sealing lip. In case of soft shafts or special applications it is possible to coat the shaft. Due to the large number of coating methods and manufacturers of coating materials a...

Fitting Instructions PTFE shaft seals are press-fitted into the receiving hole. We recommend that the sealing rings be glued into the receiving hole and/or use of a sealing/joining compound (e.g. Loctite 601, 641). In case of critical applications this prevents the risk of potential leakage occurring at the outer diameter. Recommended Diameters of Lead-In Chamfers Shaft-0 d1 [mm] Taper-0 d2 [mm] When fitting shaft seals absolute care must be taken to protect the PTFE sealing lip from damage. We recommend use of a conical fitting tool. When fitting the seal in the direction of the molded...