Overview
The PI 4750 RS 5750 ESC 2L1 SpiralTrac is a patented throat bushing manufactured by EnviroSeal Engineering for controlling internal stuffing box environments in rotating process equipment. This split-installation SpiralTrac design allows in-place installation without equipment shutdown. The carbon graphite filled PTFE (ESC) construction provides excellent chemical compatibility and wear resistance in demanding industrial pump and mechanical seal applications.
Key Features
- Patented spiral groove design — removes particulates from stuffing box and prevents debris contact with packing or mechanical seals
- Reduced or eliminated flush requirement — operates effectively with minimal or no external flush in many applications
- Active cooling circulation — minimizes heat buildup around seal faces through controlled flow dynamics
- Split installation capability — fits standard 4.75″ shaft with 5.75″ seal cavity bore for retrofitting without equipment removal
- Contamination barrier — air venting prevents stuffing box flooding while maintaining separation from fibrous process media
- Extended equipment life — reduces downtime associated with premature seal and packing wear
Technical Specifications
| Shaft Diameter | 4.75 inches |
| Seal Cavity Bore Diameter | 5.75 inches |
| Material Composition | Carbon Graphite Filled PTFE (ESC) |
| Installation Type | Split — in-place installation |
| Rotation Direction | Right (R) — clockwise from motor end |
| Lantern Ring Configuration | 2L1 — supports 2 packing rings with 1.0″ lantern ring |
| Design Version | Environmental Controller — Type A Seal or Packing Configuration |
| Minimum Axial Length | 1.25 inches |
| Typical Operating Pressure | Verify with pump specification |
| Chemical Compatibility | PTFE suitable for most industrial fluids and chemical services |
| Manufacturer | EnviroSeal Engineering Products Ltd. |
Typical Applications
- Centrifugal pumps — refinery, petrochemical, and chemical process service
- Pulp and paper equipment — refiners and process pumps handling fibrous media
- Water and wastewater systems — municipal and industrial treatment facilities
- HVAC circulation pumps — cooling tower and closed-loop systems
- Mechanical seal support — replacement for conventional throats bushings and packing rings
- Low-flush/no-flush applications — reduces external seal flush requirements in environmentally sensitive operations
Compatibility & Replacements
Compatible With
- Pumps with 4.75″ rotating shaft diameter and 5.75″ stuffing box cavity bore
- Compression packing arrangements with 2 packing rings and 1.0″ lantern ring
- Chesterton and third-party mechanical seal systems
- A.W. Chesterton SuperSet packing assemblies
- Pumps requiring right-hand (clockwise) rotation sealing
- Flush or low-flush seal configurations
Replaces / Drop-In Replacement For
- Standard L-shaped throat bushings in 4.75″ x 5.75″ cavity configurations
- Conventional packing lantern rings in equivalent pump cavity geometry
- Legacy environmental control bushings in centrifugal pump services
Works With
- Chesterton API Plan 53A seal support systems
- Standard mechanical seal kits for 4.75″ shaft applications
- Industrial packing grades (PTFE-impregnated, graphite, and aramid)
- Minimal flush or barrier fluid systems in chemical services
- Double-ended pump applications (when paired with left-rotation SpiralTrac for opposite end)












