No lubrication, yet precise dosing: How do you tackle this safely?

HNP-M Micro gear pump | Photo: HNP-M GmbH

Gather BGII special max 450C and 300 bar system pressure | Photo: Gather Industrie GmbH

Gather magnetic drive gear pump animation | Photo: Gather Industrie Gmbh

Dosing systems | Photo: Suurmond BV

Pumping and dosing solvents and other low-viscosity, non-lubricating liquids leaves no margin for error. A low viscosity, high vapour pressure and an increased risk of leakage or cavitation make these critical fluids a constant challenge in the process industry. What demands does this place on your installation—and how do you guarantee maximum safety alongside dosing accuracy?

Solvents such as acetone, toluene, alcohols, and ether are indispensable in the chemical and pharmaceutical industries, yet they remain among the most difficult media to process. Without the right equipment, low viscosity, a lack of lubricating properties, and rapid evaporation quickly lead to wear on plain bearings or seals, loss of capacity, and unsafe working conditions.

Three critical factors for non-lubricating liquids

When dosing safely and accurately, three technical challenges take center stage:

• Lubricating properties:
  Many thin liquids offer virtually no lubrication. This imposes specific requirements on the material selection for pump components such as plain bearings and shaft seals.
• Vapour pressure and cavitation:
  As soon as the pressure inside the pump housing drops below the vapour pressure of the fluid, gas bubbles form. This results in vibration, internal damage, and dosing inaccuracies.
• Safety and emissions:
  Leakage of volatile or flammable substances is unacceptable, particularly in light of increasingly stringent environmental and safety regulations such as TA-Luft and ATEX.

The solution: positive displacement gear pumps

To transfer critical fluids with utmost precision, a pulsation-free and consistently performing flow is essential. Gear pumps provide the ideal technology for this purpose. Thanks to their positive displacement operation, they maintain accurate dosing—even with fluids exhibiting a viscosity significantly lower than that of water.

Specialised gear pumps, such as those from Suurmond, address these challenges with:

• Advanced seal and plain bearing technology:
  A choice of high-grade mechanical seals, magnetic drives, or specialized packings guarantees fluid- and vapour-tightness. Internal flushing channels ensure the lubricating film is maintained.
• Wear-resistant material combinations:
  Bearings and shafts made from materials such as silicon carbide, zirconia, or specific alloys prevent wear when handling non-lubricating media.
• Pulsation-free dosing:
  A direct, continuous output ensures high-quality process control without fluctuations.

Bespoke engineering for your process

Because exact temperatures, pressures, viscosities, and chemical compositions vary per application, a tailored approach is essential. By combining application expertise with custom-configured gear pumps, a setup is created that seamlessly aligns with your process requirements while safeguarding plant security.

Written by

Suurmond BV

Read more