Features mechanical seal type 21
- California Residents: PROPOSITION 65 WARNING
- 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.
Recommended Applications type 21
- Process pumps
- Other rotating equipment
About Mechanical seal type 21
Our general-purpose Type 21 mechanical seal has become the industry standard for OEM designers.
Automatic adjustment compensates for abnormal shaft-end play, run-out, primary ring wear and equipment tolerances.
The Type 21 is ideal for use in centrifugal, rotary and turbine pumps, compressors, chillers and other rotary shaft equipment. It is also commonly used by the wastewater and water systems industries for applications such as waste treatment, potable water and HVAC.
Design Features mechanical seal type 21
- 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
Material mechanical seal type 21
- Face/Primary Ring: Carbon
- Retainer/Disc/Drive Band/ Spring Holder: 18-8 Stainless Steel
- Bellows: Buna-N
- Springs: 18-8 Stainless Steel
Operating range mechanical seal type 21
-40°F to 400°F/-40°C to 205°C (depending on materials used)
150 psi(g)/10 bar(g)
Up to 2500fpm/13m/s, depending on configuration and shaft size
Product Description type 21
- The Type 21, a general purpose seal, has become an industry standard with OEM designers. Made of stainless steel, it provides a service range well beyond that which is possible with comparably priced seals of other metallurgical construction.
- The positive static seal between the bellows and the shaft, along with the free movement of the bellows, means that there is no sliding action could lead to shaft damage by fretting. This ensures that the seal will automatically compensate for normal shaft run-out and axial movements.
- 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.