Rotary Seal Design Guide - Seals Unlimited

Catalog EPS 5350/USAEngineeringCatalog EPS 5350/USAEngineeringHelical Springs — H Series2The H Series spring is made fromflat ribbon metal strip stock that isformed into a helix shape. The standardmaterial is 17/7 PH stainless steel, andElgiloy ® is offered as an option. Thefinished spring produces a very highload versus deflection curve as shownin Figure 2-14 on Page 2-16.The helical spring design isintended for static applications due tothe high unit load. It can be used in veryslow or infrequent dynamic conditionswhen friction and wear are secondaryconcerns to positive sealing.Features• Helical wound ribbon spring with high load vs. deflection• Standard inch/fractional and MIL-G-5514 sizes• Standard 17/7 PH stainless steel springs• NACE compliant Elgiloy springs available• Available as external & internal pressure face sealsRecommended ApplicationsH Series / Helical2The H series spring producesevenly distributed load across eachindividual band, with very small gapsbetween the coils. This tight spacingprovides near continuous load,reducing potential leak paths. This,combined with the high unit load,makes the H series well-suited forvacuum and cryogenic applications orwhen pressure is too low to energizethe seal.• Static rods & pistons• Static internal & external pressure face seal applications• Slow dynamic applications