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Type W21 Single Spring Pump Mechanical Seals Replaced John Crane Mechanical Seals Type 21

Features

• The drive band's "dent and groove" design eliminates overstressing of the elastomer bellows to prevent bellows slip and protect the shaft and sleeve from wear • Non-clogging, single-coil spring provides greater dependability than multiple spring designs and will not foul due to fluid contact • Flexible elastomer bellows automatically compensates for abnormal shaft-end play, run-out, primary ring wear and equipment tolerances • Self-aligning unit automatically adjusts for shaft end play and run-out • Eliminates potential shaft fretting damage between the seal and shaft • Positive mechanical drive protects the elastomer bellows from overstressing • Single coil spring improves tolerance to clogging • Simple to fit and field repairable • Can be used with practically any type of mating ring

Operation Ranges

• Temperature: -40˚F to 400°F/-40˚C to 205°C (depending on materials used) • Pressure: up to 150 psi(g)/11 bar(g) • Speed: up to 2500 fpm/13 m/ s (depending on configuration and shaft size) • This versatile seal can be used on a wide range of equipment including centrifugal, rotary and turbine pumps, compressors, mixers, blenders, chillers, agitators, and other rotary shaft equipment • Ideal for pulp and paper, pool and spa, water, food processing, wastewater treatment, and other general applications

Recommended Application

  • Centrifugal Pumps
  • Slurry Pumps
  • Submersible Pumps
  • Mixers & Agitators
  • Compressors
  • Autoclaves
  • Pulpers

Combination Material

Rotary Face  Carbon graphite resin impregnated Silicon carbide (RBSIC) Hot-Pressing Carbon C Stationary Seat  Aluminium oxide (Ceramic) Silicon carbide (RBSIC) Tungsten carbide Auxiliary Seal Nitrile-Butadiene-Rubber (NBR) Fluorocarbon-Rubber (Viton) Ethylene-Propylene-Diene (EPDM) Spring Stainless Steel (SUS304, SUS316) Metal Parts Stainless Steel (SUS304, SUS316)

Type W21 DIMENSION DATA SHEET (INCHES)