Leybold E and DK Rotary Piston Pumps

Rotary piston pumps are built for heavy industrial duty. They handle large gas loads, dirty processes and continuous running in vacuum furnaces, metallurgy and coating lines, and many have run for decades. Leybold makes two families: E single-stage pumps for high throughput and DK two-stage pumps for lower ultimate pressure. At Provac Sales, we supply Leybold piston pumps new and rebuilt, and we repair and rebuild them in our own shop.

Leybold Piston Pump Models We Carry

E Single-Stage Piston Pumps

• Leybold E-75, rebuilt
• Leybold E-150
• Leybold E-250, new and rebuilt, about 250 m³/h (147 CFM) pumping speed and 290 m³/h nominal

DK Two-Stage Piston Pumps

• Leybold DK-50, rebuilt
• Leybold DK-100, rebuilt
• Leybold DK-200, rebuilt, about 200 m³/h (118 CFM) pumping speed and 225 m³/h nominal

The number in each model roughly reflects its pumping speed in m³/h. Some listings show a price and others are quote-based. Each product page lists pumping speed, motor and connections.

E vs DK: Single-Stage or Two-Stage?

• E pumps are single-stage. The E-250 reaches an ultimate partial pressure below about 4 x 10⁻² mbar (3 x 10⁻² Torr) without gas ballast and tolerates about 60 mbar of water vapor. Choose E pumps for high throughput, wet processes and rough vacuum.
• DK pumps are two-stage. The DK-200 reaches below about 5 x 10⁻⁴ mbar (4 x 10⁻⁴ Torr) without gas ballast and tolerates about 26 mbar of water vapor. Choose DK pumps when you need deeper vacuum, such as backing diffusion pumps.

If your process runs above about 1 mbar with lots of vapor, an E pump is usually the better choice. If you need to go well below 0.1 mbar, choose a DK.

How a Rotary Piston Pump Works

An eccentric drives a piston around inside a cylinder. A hollow slide valve attached to the piston moves in a pivoting guide and acts as the inlet. As the piston turns, the space behind it expands and draws in gas, while the space ahead of it shrinks and pushes gas out through the exhaust valve. Oil seals the clearances, lubricates and cools the pump. Because the piston never touches the cylinder wall and the clearances are larger than in a vane pump, piston pumps tolerate dust and dirt well. Leybold E and DK pumps include gas ballast and a built-in anti-reverse lock.

Key Features

• Non-contact rotary piston design for long life on dirty processes
• Gas ballast for water vapor and condensables
• Built-in anti-reverse lock
• Modular design for easier service
• Optional oil filter units, oil control units and the OF 1000 oil filtering system
• 50 Hz and 60 Hz US motor versions

Applications

• Vacuum heat treatment, sintering and brazing furnaces
• Vacuum metallurgy, melting and degassing
• Impregnating, drying and degassing in electrical engineering
• Coating and semiconductor processes
• Chemical processing and drying cabinets
• Backing RUVAC Roots blowers, and diffusion and vapor booster pumps

Pairing with Roots Blowers

E and DK pumps are classic backing pumps for Leybold RUVAC blowers. An E-250 or DK-200 with a RUVAC WA 1001 or 2001 is a common combination in furnace and coating systems, giving high pumping speed at low pressure. Ask us to size a blower to your piston pump.

How to Choose the Right Leybold Piston Pump

Before ordering, confirm:

• Ultimate and working pressure required
• Pumping speed at your working pressure
• Water vapor and other condensable loads
• Supply voltage, phase and frequency
• Whether the pump will back a Roots blower or diffusion pump
• Footprint, foundation and lifting requirements, since these are heavy pumps

Maintenance Tips

• Check oil level and condition daily on heavy-duty processes
• Change oil when it turns dark or milky, and change it more often on wet or dirty processes
• Run gas ballast open when pumping water vapor
• Use the oil grade specified in the manual, such as LEYBONOL LVO 100 mineral oil or LVO 210 ester oil for hotter duty
• Inspect belts, couplings and motor mounts for wear
• Consider an OF 1000 oil filtering system on contaminating processes

Signs Your Piston Pump Needs Service

• The pump no longer reaches its usual base pressure
• Knocking, rattling or new vibration
• Oil leaks at the shaft seal or covers
• Oil that turns milky or dark soon after a change
• The pump runs hot or trips its motor protection

New vs Rebuilt Leybold Piston Pumps

Many E and DK pumps in service today are no longer made new in every size, so rebuilt pumps are often the fastest and most cost-effective way to replace a failed unit. Rebuilt pumps are cleaned, fitted with new wear parts and seals as needed, and tested before shipping, and they fit the same foundation, piping and wiring.

Parts and Accessories

Common parts for E and DK pumps include gasket and seal kits, exhaust valves, sight glasses, couplings and oil mist filters. Send us your model and serial number and we will confirm the right parts.

Installation Tips

E and DK pumps are heavy and produce more vibration than vane pumps of similar speed, so mount them on a solid floor or foundation and use flexible connections at the inlet and exhaust. Run the exhaust to a safe location with an oil mist filter or separator, and keep the pump area well ventilated so the motor and housing stay within temperature limits.

Leybold Piston Pumps Repair

Provac Sales repairs and rebuilds Leybold E and DK rotary piston pumps. Submit an RMA request, complete the contamination data sheet and drain the oil before shipping. Include the model, serial number and symptoms. See our pump repair page for more information.

Related Leybold Collections

• Leybold blowers and boosters, RUVAC blowers for piston pump systems
• Leybold oil filtration systems, OF 1000 for E and DK pumps
• Leybold diffusion pumps, DIP pumps backed by DK pumps
• Leybold vacuum fluids and greases, LEYBONOL piston pump oils
• All Leybold vacuum pumps
• All piston pumps from every brand we carry

Leybold Piston Pumps FAQ

1. What is the difference between Leybold E and DK piston pumps?

E pumps are single-stage pumps for high throughput and wet processes, reaching about 4 x 10⁻² mbar. DK pumps are two-stage pumps reaching about 5 x 10⁻⁴ mbar, for deeper vacuum and diffusion pump backing.

2. What is the pumping speed of a Leybold E-250?

The E-250 has a pumping speed of about 250 m³/h, or 147 CFM, and a nominal speed of about 290 m³/h.

3. What oil does a Leybold E or DK pump use?

Leybold lists LEYBONOL LVO 100 mineral oil as standard for E and DK pumps, LVO 210 ester oil for higher temperatures, and PFPE oil for oxygen or aggressive gases in PFPE-prepared pumps.

4. Can a DK-200 back a Roots blower?

Yes. E and DK pumps are common backing pumps for RUVAC blowers and diffusion pumps. Send us your process pressure and we will size the combination.

5. Are rebuilt Leybold piston pumps reliable?

Yes. Rebuilt E and DK pumps are cleaned, fitted with new wear parts and seals as needed, and tested before shipping. They fit the same foundation, piping and wiring as the pump they replace.

Request a Quote on Leybold E and DK Rotary Piston Pumps

Send us your required ultimate pressure, pumping speed, supply voltage and application. We will recommend the right E or DK pump, confirm new or rebuilt availability, or quote a repair of your existing pump. Contact us or call 831-462-8900.