T21 Mechanical Seal

Mostly Use: Water, Oil And Other Low Corrosion Liquids

The T21 seals are part if the diaphragm rubber bellow seals and are interchangeable with various other makes including John Crane Type 1, 2 and 21.  The bellow rotates with the shaft and can accommodate some end float, eccentricity and misalignment.  These seals come in Metric and Imperial sizes.


Positive Drive: Reduces bellow stress
Self Adjusting: Bellow takes care of wear & shaft float
Long Life: Due to minimum face loading
Non clogging: Open spring design
Non Fretting: No moving O-rings
Bi-directional: Due to positive drive

Service Capability

Max. Speed: 15 m/sec
Max. Pressure: 14 bar
Temp.: -40⁰C to 200⁰C
Media: Dependent on Materials

* See P.V. Curves for max.


P.V. Curves for water @ 20⁰C


Rotary Face: Car, Sil, TC
Stat Face: Cer, Sil, TC
Spring: 304 Stainless Steel
Elastomer:  Nitrile / Viton / EPDM
Metal Parts: 316 Stainless Steel

T21 – Metric

Table data to go here

T21 – Imperial

Table data to go here