Type SAF John crane

O-ring Pusher seals | Heavy-duty Cartridge Seal for Boiler Feed Circuit Applications

Type SAF John crane

Features mechanical seal Type SAF

  • California Residents: PROPOSITION 65 WARNING
  • Balanced, heavy-duty design
  • Easy to install
  • No fitting parts needed
  • No measuring required
  • Self-centering

Recommended Applications Type SAF

  • Process pumps

About Mechanical seal Type SAF

The SAF is a double-acting seal particularly engineered to suit pumps, screens, knotters, sorters and pulpers in heavy process industries where liquids containing solid particles and impurities are involved. Seal design can be multi-component or cartridge version, depending on application. Size range varies from 0.787” to 17.716”/20mm to 450mm.

Typical OEM designs include brands: Andritz, Beloit, Bird, GL&V, IMPCO, Metso Paper, Netsch Mohno, Noss, Voith, Toscotec,SSP Pumps, Sulzer Pumps, Sunds Defibrator and Warman Pumps, etc.

Design is unaffected by pressure changes. The Type SAF seal is double-balanced, which makes the construction fully independent of pressure changes in both process and barrier fluid. It’s designed for minimum damage risk — the rugged construction for all applications prevents failure and provides long and trouble-free service. Type SAF seal provides easy installation and low maintenance costs. Ultimate reliability for screen sealing requirements. It is recommended to use Safeunit™ (plan 54) for seal water control.

Operating range mechanical seal Type SAF

  • Temperature Limits 350°F/180°C
  • Pressure Limits Stuffing box pressure: 290 psi(g)/20 bar(g) Seal water pressure: 215 psi(g)/15 bar(g)
  • Speed Limits 100fps/30m/s

Standard Materials Type SAF

  • Seal faces: SiC/SiC (product side),

  • SiC/Carbon (atmosphere side)


  • O-rings: PTFE (product side), EPDM, Viton


  • Metals: AISI 329 (standard), titanium, UHB


  • Springs: Nimonic steel