Rotary Seal Design Guide - Seals Unlimited

Catalog EPS 5350/USAEngineeringPTFE Shaft SealsHow Do I Choose the Right Profile for MyApplication?Parker’s PTFE product line includes bothstandard designs for the most commonapplications and custom designs that ourengineers can help you develop.For the long term, we suggest that youfamiliarize yourself with the design elements in thisEngineering section that are critical whenchoosing a FlexiLip, FlexiCase or FlexiSeal ® .For quick reference and ease of sortingthrough the many standard designs, we haveprovided simple decision trees and placed themthroughout this design guide. If it becomesapparent that you need a custom design to meetyour unique needs, or if you just want us to confirmthe standard seal choice you’ve made, pleasecontact Parker’s PTFE Engineering team at801-972-3000.Parker designs and manufactures a completeline of PTFE seals for both reciprocating androtary applications. This guide focuses on sealsfor rotary applications. For reciprocatingapplications please refer to publication EPS 5340PTFE Lip Seal Design Guide.PTFE lip seals are commonly used as anupgrade over elastomeric lip seals whenconditions are severe. Common reasons forupgrading to a PTFE material include chemicalcompatibility, poor lubrication at the lip, highpressure, high speed or high temperature.For rotary applications, Parker offers threeprimary design groups: FlexiLip, FlexiCase andFlexiSeal.LF LE LG LM LDFlexiLip seals are available in the above basicprofiles. Excluder lips and internal metal stabilizerbands can be added to each profile depending onapplication requirements. The main difference isthe shape of the primary lip. Additional optionsare available for the lip and O-ring material foradded design flexibility.LF = Mandrel Formed LipLE = Elf Toe LipLG = Lip With Garter SpringLM = Machined LipLD = Dual LipFlexiLip seals are intended for continuousrunning rotary shafts under various operatingconditions. An O-ring is used on the OD forpositive static sealing and proper bore retention.Typical operating limits are up to 6,000 sfpm,150 psi and 450 °F (30 m/s, 10 bar and 232 °C).See Table 9-4 on Page 9-10 for specific limits.CF CM CE CD CH CGFlexiCase designs feature PTFE lip elementsencased in a metal jacket and are available in theabove basic profiles. FlexiCase designs can beused in the same applications as FlexiLip profileswhere more bore retention is required. Excluderlips can be added for additional exclusion capacity.Additional options are available for the lip andcase material for added design flexibility. Typicaloperating limits are 6,000 sfpm, 500 psi and 450°F (30 m/s, 34 bar and 232 °C).CF = Mandrel Formed LipCM = Machined Lip FormCE = Elf Toe LipCD = Dual LipsCH = High Pressure Dual LipCG = Lip With Garter SpringFC FH FFFlexiSeal rotary seals are spring-energizeddesigns and are available in the basic profilesabove. Three spring options are available for eachprofile: cantilever, canted-coil and helical. Shaftspeeds are very limited (below 1,000 sfpm or5 m/s) but they can provide positive sealing to10,000 psi (690 bar). This is the preferred designfor rotating unions as well as oscillating and slowrotating shafts under high pressure conditions.03/28/06222-15 Parker Hannifin CorporationEPS DivisionToll Free: (800) 233-3900www.parkerseals.com