To do pipe flushing correctly we need to provide the special conditions to create turbulent flow. This is required to remove particles from the surface inside spindle tubes. For that we need:
- High velocity of the flushing fluid (not be less than 2 to 3 m/sec. = 106 ft./sec.)
- High temperature of the flushing fluid (a minimum temperature should be 140°F = 60°C)
- Low viscosity of the flushing fluid (in the 10 to 15 cSt range at 104°F = 40°C)
- The pressure of the flushing fluid should be held to a minimum 3 to 5 bar (22 to 73 psi), measured downstream from the flushing circuit, before the return line filter and sampling port
- The flushing time to be 30 min.
Next good references about flushing I found in the internet and want to share: