TTI’s suggestions are dependent upon system size and contaminant levels. Achieving and maintaining these suggested ISO codes may require the use of a prescribed cleanliness program.
| System Component | TTI Suggested | Industry Standard | TTI Suggested | Industry Standard | TTI Suggested | Industry Standard |
| System Pressure Rating | < 2000 psi | (138 bar) | 2000-3000 psi | (138-207 bar) | > 3000 psi | (207 bar) |
| Pumps | ||||||
| Variable Vane | ≤16/14/11 | 18/16/13 | ≤15/13/10 | 17/15/12 | – | – |
| Variable Piston | ≤16/14/11 | 18/16/13 | ≤15/13/10 | 17/15/12 | ≤15/13/10 | 17/15/12 |
| Fixed Vane | ≤17/15/12 | 20/18/15 | ≤16/14/11 | 19/17/14 | ≤15/13/10 | 18/16/13 |
| Fixed Piston | ≤16/14/11 | 19/17/14 | ≤15/13/10 | 18/16/13 | ≤15/13/10 | 17/15/12 |
| Fixed Gear | ≤17/15/12 | 20/18/15 | ≤16/14/11 | 19/17/15 | – | – |
| Valves | ||||||
| Servo Valve | ≤14/12/9 | 16/14/11 | ≤14/12/9 | 16/14/11 | ≤13/11/8 | 15/13/10 |
| Proportional Pressure | ≤15/13/10 | 17/15/12 | ≤15/13/10 | 17/15/12 | ≤14/12/9 | 16/14/11 |
| Proportional Flow | ≤15/13/10 | 17/15/12 | ≤15/13/10 | 17/15/12 | ≤14/12/9 | 16/14/11 |
| Proportional Directional | ≤15/13/10 | 17/15/12 | ≤15/13/10 | 17/15/12 | ≤14/12/9 | 16/14/11 |
| Proportional Cartridge Valve | ≤15/13/10 | 17/15/12 | ≤15/13/10 | 17/15/12 | ≤14/12/9 | 16/14/11 |
| Pressure Control Modulating | ≤17/15/12 | 19/17/14 | ≤16/14/11 | 18/16/13 | ≤15/13/10 | 17/15/12 |
| Flow Control | ≤17/15/12 | 19/17/14 | ≤16/14/11 | 18/16/13 | ≤16/14/11 | 18/16/13 |
| Directional Solenoid | ≤17/15/12 | 20/18/15 | ≤16/14/11 | 19/17/14 | ≤15/13/10 | 18/16/13 |
| Check Valve | ≤17/15/12 | 20/18/15 | ≤16/14/11 | 20/18/15 | ≤16/14/11 | 19/17/14 |
| Cartridge | ≤16/14/11 | 18/16/13 | ≤15/13/10 | 17/15/12 | ≤15/13/10 | 17/15/12 |
| Actuators | ||||||
| Radial Piston Motors | ≤16/14/11 | 17/15/12 | ≤15/13/10 | 16/14/11 | ≤15/13/10 | 15/13/10 |
| Gear Motors | ≤17/15/12 | 20/18/15 | ≤16/14/11 | 19/14/14 | ≤15/13/10 | 18/16/13 |
| Axial Piston Motors | ≤16/14/11 | 19/17/14 | ≤15/13/10 | 18/16/13 | ≤15/13/10 | 17/15/12 |
| Vane Motors | ≤17/15/12 | 20/18/14 | ≤16/14/11 | 19/17/13 | ≤15/13/10 | 18/16/13 |
| Cylinders | ≤17/15/12 | 20/18/15 | ≤16/14/11 | 19/17/14 | ≤15/13/10 | 18/16/13 |
| Bearings | ||||||
| Ball Bearing | ≤14/12/9 | 15/13/10 | ||||
| Gearbox (industrial) | ≤16/15/12 | 17/16/13 | ||||
| Journal Bearing (high speed) | ≤16/14/11 | 17/15/12 | ||||
| Journal Bearing (low speed) | ≤16/14/11 | 17/15/12 | ||||
| Roller Bearing | ≤15/13/10 | 16/14/11 | ||||
| Other | ||||||
| HP Fuel Injector | ≤15/13/10 | 16/14/11 | ≤15/13/10 | 16/14/11 | ≤15/13/10 | 16/14/11 |
| Hydrostatic Transmission | ≤16/14/11 | 17/15/13 | ≤15/13/10 | 16/14/11 | ≤15/13/10 | 16/14/11 |
| Test Stands | ≤16/14/11 | 18/16/13 | ≤15/13/10 | 18/16/13 | ≤15/13/10 | 18/16/13 |
