Well-run products, skilled income group, and better after-sales products and services; We have been also a unified massive family, all people stick with the business price “unification, dedication, tolerance” for Type 21 mechanical seal for marine industry John crane, We have ISO 9001 Certification and qualified this product or service .in excess of 16 years experiences in manufacturing and designing, so our goods featured with very best high-quality and aggressive rate. Welcome cooperation with us!
Well-run products, skilled income group, and better after-sales products and services; We have been also a unified massive family, all people stick with the business price “unification, dedication, tolerance” for , With good quality, reasonable price and sincere service, we enjoy a good reputation. Merchandise are exported to South America, Australia, Southeast Asia and so on. Warmly welcome customers at home and abroad to cooperate with us for the brilliant future.
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)
Type 21 mechanical seal for marine industry











