- Lancashire ; 10,000 ppm
- 2 - Pass Economic ; 4,500 ppm
- Package and 3 - Pass Economic ; 3,000 - 3,500 ppm
- Low Pressure Water Tube ; 2,000 - 3,000 ppm
- Medium Pressure Water Tube ; 1,500 ppm
- Coil Boilers and Generators ; 2,000 ppm
The above figures are offered as a broad guide only, the boiler maker should always be consulted for specific recommendations.
Source - Spirax Sarco