Function and Importance of the Oil Purifier Drain Valve

Discover the vital role of the oil purifier drain valve. Learn its functions, benefits, and best practices to improve oil purification efficiency, protect equipment, and ensure safe operation.

Introduction: Why the Drain Valve Matters?

In oil purification systems, every component has a purpose—but some, though small, are absolutely critical. The drain valve, also called a drain/bleed valve or air release valve, is one such part. Its main function is to evacuate unwanted fluids such as air, water, or residual oil, ensuring that the oil purifier works at maximum efficiency, delivers consistent results, and operates safely.

Core Functions of the Oil Purifier Drain Valve

The drain valve performs three essential evacuation tasks that directly affect oil purification quality and equipment performance:

    -------------- Primary Function --------------------         ----------------------------------- Applications & Scenarios -------------------------------------------------

1. Evacuating Air (De-aeration / Bleeding)                     Startup: Removes trapped air from pipelines and vacuum chambers, preventing airlocks and helping                                                                                        the vacuum pump quickly achieve the required vacuum level.

                                                                                             Operation: Vents dissolved gases released from the oil to maintain system stability.

    2. Draining Separated Water                                           Routine Maintenance: Periodically removes water collected in the bottom of the vacuum chamber or 

                                                                                             coa lescer tank.

                                                                                             Shutdown/Storage: Empties residual moisture to prevent corrosion when equipment is idle.

    3. Purging Residual Oil                                                    Servicing & Oil Changes: Ensures complete oil drainage before filter replacement, cleaning, or 

                                                                                             long-term storage.

                                                                                             Transportation: Reduces system weight and prevents oil leaks during movement.

Why the Drain Valve Is Critical for Performance

1. Ensures Purification Efficiency

Vacuum Integrity: In vacuum oil purifiers, trapped air makes it impossible to achieve deep vacuum levels (e.g., –0.095 MPa), reducing dehydration and degassing efficiency.

Stable Flow & Pressure: Eliminating air prevents pump cavitation, flow resistance, and pressure fluctuations that can damage pumps and reduce service life.

2. Protects Equipment & Ensures Safety

Prevents Corrosion: Regular drainage removes accumulated water, protecting tanks, pipes, and internal components from rust and damage.

Avoids Freeze Damage: In cold environments, water must be drained to prevent freezing and cracking of system parts.

3. Guarantees Final Oil Purity

If separated water is not removed, it can overflow and be reabsorbed by the pump, contaminating purified oil and reversing the purification process.

Best Practices for Safe and Effective Operation

Bleeding Air Before Startup: Open the drain/air valve, run the pump briefly, and close it once a steady, bubble-free oil stream flows out.

Routine Water Drainage: Monitor the sight glass or collection bowl during operation. Manually drain as needed, or rely on automatic drain valves in advanced systems.

Safety First:

Only open the valve when the oil has cooled below 50°C (122°F) to avoid burns.

Collect drained oil and water properly in line with environmental regulations—never discharge directly into the environment.

Conclusion

The drain valve may be a small component, but it serves as the oil purifier’s waste disposal system—removing air, water, and residual oil to ensure smooth operation. When used correctly, it not only improves purification efficiency but also extends equipment lifespan, guarantees oil purity, and protects operators and systems.

Key takeaway: Proper use and maintenance of the drain valve is fundamental to achieving the best performance from your oil purifier.