Oil-Sealed vs Dry vs Liquid Ring Vacuum Pumps: How to Choose the Right Atlas Copco Pump

Choosing a vacuum pump looks simple until you compare the options. Oil-sealed, dry and liquid ring pumps all create vacuum, but they behave very differently in a real plant. The wrong choice can mean contaminated product, frequent oil changes or a pump that struggles with moisture.

This guide explains how the three technologies differ, which Atlas Copco ranges belong to each, and what to prepare before you ask for a quote. It is written for plant managers, maintenance heads and purchase teams in Rajasthan and across India.

Quick comparison

Technology Best for Watch out for Atlas Copco ranges
Oil-sealed Clean, dry gases; packaging, plastics, woodworking, general industry Oil changes and handling oil in the exhaust GVD, GVS A, GVS VSD+, GHS VSD+, GLS rotary piston
Dry Processes where oil contamination is not acceptable Often a higher purchase price than oil-sealed DZS claw, DSS scroll, DWS screw, DVS vane, DRB/ZRS boosters
Liquid ring Wet, humid or vapour-heavy gas streams Needs a service liquid supply and its management AWS, AWD, AWC, AWL, LRP VSD+

1. Oil-sealed vacuum pumps

In an oil-sealed pump, oil seals the internal clearances, lubricates the moving parts and carries heat away. This is mature, proven technology that reaches a deep vacuum reliably, so it is common in packaging, moulding, printing and general manufacturing.

Atlas Copco's range covers rotary vane pumps (GVD, GVS A and GVS VSD+), oil-sealed screw pumps (GHS VSD+) and heavy-duty rotary piston pumps (GLS) for harsh process duties such as heat treatment, coating and transformer drying.

Good fit if: your gas is clean and dry, and your team is comfortable with regular oil and filter maintenance.

See the full range on our oil-sealed vacuum pumps page.

Atlas Copco GHS VSD+ oil-sealed screw vacuum pump
Atlas Copco GHS VSD+ oil-sealed screw vacuum pump

2. Dry vacuum pumps

Dry pumps keep oil out of the pumping chamber. The process and the exhaust stay free of oil, and there is no oil to change or dispose of. That makes them the preferred choice where contamination matters, such as food, pharma, electronics and pneumatic conveying.

The Atlas Copco dry range includes claw pumps (DZS), scroll pumps (DSS), screw pumps (DWS), rotary vane pumps (DVS) and mechanical booster pumps (DRB/ZRS) that shorten evacuation time on large chambers.

Good fit if: oil in the process or exhaust is a risk, or you want to remove oil handling from your maintenance schedule.

Compare models on our dry claw vacuum pump page.

Atlas Copco DZS dry claw vacuum pump
Atlas Copco DZS dry claw vacuum pump

3. Liquid ring vacuum pumps

A liquid ring pump uses a ring of service liquid, usually water, as the seal. Because of this, it tolerates water vapour, condensable gases and small amounts of liquid carry-over that would harm other pump types. That is why liquid ring technology is common in chemical, paper, sugar and food plants.

The Atlas Copco range includes single-stage (AWS), two-stage (AWD), AWC and AWL pumps, plus the LRP VSD+, a connected liquid ring pump with Class 0 certified oil-free operation and variable speed control.

Good fit if: your gas stream is wet, saturated or carries vapour. Note that the achievable vacuum depends partly on the temperature of the service liquid.

Explore our liquid ring vacuum pumps for wet and vapour-laden processes.

Atlas Copco AWS A single-stage liquid ring vacuum pump
Atlas Copco AWS A liquid ring vacuum pump

How to cut the running cost of your vacuum system

  • Size for real demand. A pump chosen for the worst case wastes energy the rest of the shift.
  • Consider variable speed (VSD). Where demand rises and falls, a VSD pump matches its output to what the process needs.
  • Fix leaks. Leaks in the vacuum network make pumps work harder for the same result.
  • Use smart control. Controllers such as HEX@ and HEX@GRID give remote visibility and coordinate several pumps as one system, which helps with planning maintenance.
  • Match technology to the gas. Choosing the right pump type avoids losses from contamination and frequent servicing.

What to prepare before asking for a quote

A correct recommendation depends on a few facts. Have these ready:

  • Required pumping speed and the vacuum level at the process
  • Gas composition: dry, humid, solvent-laden or dusty
  • Duty cycle: continuous, shift-based or intermittent
  • Site conditions: ambient temperature, available utilities, space
  • Whether you need a single machine, a point-of-use pump or a central vacuum system

With this information, we can compare technologies on running cost and maintenance as well as purchase price.

Industries that use these pumps

Atlas Copco vacuum technology is used in packaging, plastics, glass bottle manufacturing, woodworking, canning, food and dairy, chemical processing, power generation and many other sectors. The right pump depends on the application, not just the industry, so share your process details when you ask.

Frequently asked questions

Which is better, an oil-sealed or a dry vacuum pump?

It depends on the process. Oil-sealed pumps are proven and economical for clean, dry gases. Dry pumps suit processes where oil must stay out of the product or exhaust, and they remove oil changes from the maintenance plan.

When should I choose a liquid ring pump?

Choose it when the gas is wet, saturated or carries condensable vapour, or when small amounts of liquid may enter the pump.

What decides the price of a vacuum pump?

Pumping speed, vacuum level, oil-sealed or dry design, motor rating, whether a variable speed drive is included, and accessories such as filters or a tank-mounted package. Share your application details to get an accurate quote.

Atlas Copco vacuum solutions in Rajasthan

N B Mercantile has supplied industrial equipment since 1996 and is the exclusive channel partner for Atlas Copco in Rajasthan. We work from our Udaipur head office and branches in Jaipur, Jodhpur, Bhilwara and Bhiwadi, and regularly support plants in Kota. Supply to other parts of India can be arranged on request.

Browse the complete range on our Atlas Copco vacuum solutions page, see our wider Atlas Copco compressor and air treatment range, or send us your application details for a recommendation.

Talk to our team: call +91 9001 894 490, email info@nbmercantile.com or message us on WhatsApp.

Comments

Post a Comment

Popular posts from this blog

What Is a Dry Rotary Vane Vacuum Pump and How Does It Work?

In many industrial setups, air removal plays a quiet but important role. When pressure drops inside a chamber, processes begin to behave differently. A Dry Rotary Vane Vacuum Pump handles this task without using oil inside the compression chamber, which changes how maintenance and performance are managed over time. In most cases, industries that deal with clean processes prefer such pumps because contamination risk stays low. NB Mercantile has been supplying these systems to various sectors where controlled vacuum conditions matter more than raw power. Internal Working Mechanism Inside the pump, a rotor sits slightly off-center. As it rotates, vanes slide in and out, creating pockets of space. These pockets trap air and move it along the chamber until it exits through the outlet. This movement may seem simple, but the absence of oil changes the internal dynamics. Friction and sealing depend more on precision engineering rather than lubrication. Over time, this design tends to reduce i...
Read more

Top Industrial Machinery Suppliers in India for Reliable & Advanced Solutions

Across manufacturing hubs and process plants, dependable machinery shapes daily operations. Production targets, safety standards, and maintenance schedules often depend on the efficiency of suppliers who understand industrial demands at ground level. When companies search for Industrial Machinery Suppliers in India , they usually look beyond product catalogues. They look for technical clarity, steady supply chains, and long-term service access. Changing Industrial Expectations in India Industrial development across sectors such as cement, textiles, mining, and food processing has increased the demand for specialised equipment. Many facilities now operate in tighter production cycles compared to earlier years. Downtime that once seemed manageable now directly affects cost planning and delivery commitments. In such situations, Industrial Machinery Suppliers in India are expected to provide more than equipment dispatch. They must assist with selection guidance, maintenance coordination, ...
Read more

Practical Guide For Efficient Industrial Compressed Air Systems Today

  Compressed air plays a major role in Indian factories, workshops, and processing plants. Machines, tools, and automation lines depend on a stable air source to maintain productivity. When air pressure drops or equipment fails, operations slow down and costs rise. Choosing the right compressor technology therefore becomes a business decision rather than a simple purchase, especially for growing industrial environments. Understanding The Working Method Of Screw Technology Among available options, the Oil Injected Screw Compressor has become a common choice because of its continuous duty design. Inside the system, two rotors mesh together and compress air smoothly without heavy pulsation. Oil is injected to cool, seal, and lubricate the chamber, reducing friction and heat. This results in consistent airflow, longer component life, and dependable performance. Many production facilities prefer an Oil Injected Screw Compressor when they need steady air for long hours. Unlike piston ma...
Read more