The SpiralTrac™ environmental control bushing can be found in the current main catalog on page 18 (pdf download = see below)

When used with Chesterton® mechanical seals, SpiralTrac environmental control bushings improve seal reliability through effective solids removal and improved seal chamber cooling.

-Increases seal reliability in most rotating applications
-Reduces flushing water costs in abrasive applications
-Fits all rotating equipment 

Air
Can escape from the seal chamber when the pump is stopped (eliminates crystallization, coking, overheating due to air entrapment) 

Circulation
Around the seal (excellent seal face cooling) 

Exchange
In and out of the sealing chamber (heat dissipation from the sealing chamber)

Particles
Direct removal from the sealing chamber through the spiral groove, with and without flushing

Materials:
1.4401 (316SS)
416SS
PTFE, glass fiber-filled
PTFE, carbon-filled
Bronze
Titanium / EN 3.7035
AWC800 - red polymer
Monel® K400 / EN 2.4360

Versions:
F = split
N = reduced/no flushing for liquids with solids content
D = reduced/no flushing for liquids with fibre content
P = split - packing versions
C = with drainage for crystallizing substances

Further accessories:
Flow GuardianTM pressure and flow controllers, BSS PSS supply systems,
WSS water saving systems, or Intelli-FlowTM HT, environmental controls, etc.

can be found in the catalog on pages 15-18 (see download below)

Further downloads, documentation available on request
Download: https://www.ihb.ch/media/1V25800K/CHESTERTON_MRO_2017_e.pdf
Source : A.W. Chesterton Company