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Single Spring Elastomer
Bellows Seal 


Features &


  • Cost effective seal common to many process pumps

  • Bellows design helps compensate for face wear

  • Bi-directional

  • Multiple face and elastomer choices

  • Equivalent to John Crane Type 21, Pac-Seal Type 21, US Seal C head

Standard Materials of Construction


  • Carbon Graphite (Resin Impregnated), Antimony-Impregnated Carbon, Silicon Carbide, Tungsten Carbide


  • Buna, Viton®, Aflas®, Neoprene, EPDM


  • 304, 316, Monel

Operating Limits

  • Pressure: 150 psi 10.3 Bar

  • Temperature: -40°F to +400°F.

*All industry standard “PS” numbers and seal styles are available. Just provide us with the “PS” number required or one used on previous orders.

A21 drawing
A21 dimensions
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