Which checks are critical to ensure stable soluble oil concentration with a DOSATRON D3IL10 proportional dosing pump during CNC sump refill at 1.5 m3/h?

Objective
Ensure stable proportional dosing of soluble oil with a water-powered DOSATRON D3IL10 during CNC sump refill at 1.5 m3/h by validating the installation conditions and the application parameters.

1) Hydraulic checks (key to proportional stability)

• Stable inlet pressure: keep inlet pressure within the specified operating range (0.5 to 6 bar) and limit rapid pressure variations. Steady pressure supports consistent proportional metering.
• Steady flow in the operating range: 1.5 m3/h is within the D3IL10 flow range (10 l/h to 3 m3/h). Confirm the refill flow is continuous (no cycling). When the supply is intermittent, a buffer tank or a slow-opening valve helps smooth the hydraulic conditions.
• Correct valve and by-pass configuration: confirm the by-pass is closed during dosing and that isolation valves do not create an unintended short-circuit around the pump.

2) Suction side and concentrate properties

• Leak-tight suction line: verify suction hose condition, foot valve, clamps, and O-rings to ensure an airtight assembly. A tight suction line supports repeatable concentrate draw.
• Controlled head losses: minimize suction lift, keep the suction line short and straight, and ensure the foot valve remains fully submerged to maintain consistent aspiration.
• Viscosity and temperature considerations: soluble oil viscosity changes with temperature. Use the D3IL10 viscous kit (standard) and confirm the concentrate falls within the recommended viscosity window for accurate, repeatable metering.

3) Mixing and measurement best practices

• Effective emulsification: confirm the emulsifying washer is installed and clean to promote fast, consistent emulsion formation during refill.
• Consistent sampling methodology: measure concentration after sufficient mixing time and always at the same sampling point. Refractometer readings must be taken on a well-homogenized sample to reflect the real concentration.

4) Mechanical condition for long-term accuracy

• Visual inspection of dosing components: for high-cycle applications, inspect VF seals and the dosing piston to ensure the metering mechanism remains in optimal condition for stable proportional dosing.