Liquid Ring Vacuum Pumps and Compressors

Selection & application limits – what matters in practice

To ensure a Liquid Ring Vacuum Pump operates reliably in the process, the following parameters should be clarified early on:

1) Medium & process gas (moist/wet, steam, condensate, solids)

Liquid Ring Vacuum Pumps are particularly suitable for moist, steam‑laden or “dirty” gas streams, since the operating liquid acts as a sealing and transport medium and flushes out impurities.

In practice:

• Does the gas contain condensable vapors (e.g., water vapor, solvent vapors)? → Liquid Ring is often a robust choice, as condensation can occur directly inside the pump.
• Does the gas contain entrained liquid or fluctuating loads? → Liquid Ring technology is typically less sensitive to these conditions than many dry‑running concepts.

2) Temperature & achievable ultimate vacuum

The achievable ultimate vacuum of Liquid Ring Vacuum Pumps is limited by the vapor pressure of the operating liquid: the suction pressure cannot drop below the vapor pressure of the liquid used.

Important: As the operating liquid temperature increases, vapor pressure rises and the achievable ultimate vacuum decreases.

Practical recommendation:

• For stable vacuum levels: cool the operating liquid or use a circuit with a heat exchanger.

3) Materials & corrosion/abrasion exposure

For aggressive media, abrasive particles, or scaling tendencies, material and coating selections are critical to prevent corrosion, abrasion, and performance loss.

The L‑Series offers ceramic coatings and corrosion‑resistant material options to ensure long‑term stability in wet processes.

4) Operating liquid & water management

Because the operating liquid plays a central role (sealing/cooling/condensing), proper liquid management is essential: separators, circulation, replenishment, and treatment where required.

The L‑Series highlights water‑efficient circulation concepts and robust configurations depending on model.

• Reliable performance in wet and abrasive environments
• Long-lasting materials including stainless steel and ceramic
• Reduced maintenance requirements with monobloc design
• Energy-efficient operation with advanced liquid ring technology
• Suitable for vacuum, compression, and combination applications
• International certifications, including ATEX

• Environmental Engineering
• Food and Beverage Industries
• Lifting and Handling
• Packaging Industry
• Plastics Industry

Liquid Ring vs. Screw vs. Rotary Vane – when to choose which technology?

The Liquid Ring principle is often the preferred choice when process gases are moist, steam‑laden, or contain condensate/contaminants, and when robust continuous operation is required.

Alternative technologies (e.g., dry‑running screw or rotary vane) can be suitable when the gas stream is dry and well‑defined, or when other criteria (e.g., a specific vacuum level without operating liquid) are prioritized.

Quick check:

• Moist / condensable components in the gas stream? → Liquid Ring often has the advantage
• Very deep ultimate vacuum required? → verify whether the vapor pressure limit of the operating liquid is acceptable
• Aggressive media / abrasion / scaling? → prioritize material/coating options and circulation concept