Leybold Oil Diffusion Pumps

Oil diffusion pumps remain the most economical way to get very high pumping speed in the high vacuum range. With no moving parts, they run for years with little more than an occasional oil change. Leybold diffusion pumps are installed on large coating lines, vacuum furnaces and metallurgy systems worldwide. At Provac Sales, we supply Leybold diffusion pumps and rebuild and repair them in our own shop.

Leybold Diffusion Pump Models We Carry

DIP Series

• DIP 3.000 and DIP 8.000 for mid-size coating and furnace chambers
• DIP 12.000 and DIP 20.000 for large batch coaters and furnaces
• DIP 30.000 and DIP 50.000 for very large coating and metallurgy systems

The number in each DIP model refers to its nominal pumping speed in liters per second, so a DIP 20.000 is rated at about 20,000 l/s.

DIJ Series

• Leybold DIJ 20 and DIJ 630 compact diffusion pumps for smaller systems

LEYBOJET Oil Vapor Booster

• Leybold LEYBOJET 630, an oil vapor booster pump for high gas throughput in the medium vacuum range

Some listings show a price and others are quote-based. Each product page lists inlet flange, pumping speed, heater power and fluid capacity.

Diffusion Pump vs Oil Vapor Booster

• A diffusion pump, such as the DIP and DIJ, gives maximum pumping speed at the lowest pressures, typically from about 10⁻³ mbar down to the 10⁻⁷ mbar range and below. It needs a backing pump to hold its foreline below its critical backing pressure.
• An oil vapor booster, such as the LEYBOJET 630, is built for high gas throughput between the diffusion pump range and the Roots blower range. It handles large gas loads, such as in degassing and metallurgy, and can tolerate a higher backing pressure.

How an Oil Diffusion Pump Works

An electric heater at the base of the pump boils the pump fluid. The vapor rises through a stack of jets and is forced out downward at very high speed. Gas molecules that wander into the vapor stream are driven toward the bottom of the pump, where the backing pump removes them. The water-cooled body condenses the vapor, which runs back down to the boiler. Leybold DIP pumps use three to five jet stages and a baffle design that reduces backstreaming and oil loss. Newer models use a direct heating system and an optional Energy Efficiency Controller to cut heat-up time and power use.

Key Features

• No moving parts, so there is nothing to wear out mechanically
• Very high pumping speed per dollar compared to turbo pumps of the same size
• Multi-stage jet systems for high compression and throughput
• Baffle designs that reduce oil backstreaming
• Direct heating and an optional energy efficiency controller on current DIP models
• Works with mineral, silicone or hydrocarbon pump fluids, depending on the model

Applications

• Web, roll-to-roll and optical coating
• Vacuum heat treatment and brazing furnaces
• Vacuum metallurgy and steel degassing
• Electron beam welding and melting
• Space simulation and research systems

Diffusion Pump Fluids

Leybold recommends LEYBONOL diffusion pump fluids:

• LEYBONOL LVO 500 (DIFFELEN), a mineral white oil and the most common choice, for ultimate pressures below about 10⁻⁷ mbar in DIP, DIJ and LEYBOJET pumps
• LEYBONOL LVO 521, a premium silicone fluid for high and ultra-high vacuum, offered as a replacement for discontinued DC 704 and 705 fluids
• LEYBONOL LVO 540, a hydrocarbon fluid for the LEYBOJET 630 oil vapor booster

See our Leybold vacuum fluids and greases collection for these fluids.

How to Choose the Right Leybold Diffusion Pump

Before ordering, confirm:

• Chamber volume, gas load and the working pressure you need
• Inlet flange size and whether you need a baffle or cold trap
• Heater voltage, phase and power available
• Cooling water flow and temperature
• Backing pump and Roots blower size, so the foreline stays below the critical backing pressure
• Pump fluid type, especially when matching an existing system

Maintenance Tips

• Check fluid level and condition at each service and replace fluid that has darkened or cracked
• Never expose a hot pump to air, which oxidizes mineral fluids and coats the jets
• Confirm cooling water flow before turning on the heaters
• Clean the jet stack and boiler when replacing badly degraded fluid
• Check heater elements for open circuits if heat-up time increases

Signs Your Diffusion Pump Needs Service

• Longer pumpdown or a higher base pressure than before
• Oil contamination in the chamber, which points to backstreaming
• Failed heater elements or uneven heating
• Cooling coils that are blocked or leaking
• Dark, tarry fluid or deposits on the jets

New vs Rebuilt Leybold Diffusion Pumps

Because a diffusion pump has no moving parts, a rebuilt pump can perform like new. A rebuild usually includes stripping and cleaning the body and jet stack, checking the jets for damage, replacing heater elements and seals as needed, pressure testing the cooling coils and refilling with fresh fluid. Rebuilt Leybold DIP pumps are a cost-effective way to replace a pump of the same size without changing the chamber flange, backing line or heater wiring.

Typical Diffusion Pump System

A complete high vacuum system usually stacks several pumps. A rotary vane, piston or dry pump roughs the chamber, a RUVAC Roots blower boosts speed in the mid range, and the DIP diffusion pump takes over in the high vacuum range, often with a baffle or cold trap above it. Valves let the roughing line evacuate the chamber while the diffusion pump stays hot and isolated.

Leybold Diffusion Pumps Repair

Provac Sales repairs and rebuilds Leybold DIP and DIJ diffusion pumps and LEYBOJET boosters, including jet stack cleaning, heater replacement and refilling. Submit an RMA request, complete the contamination data sheet and drain the fluid before shipping. See our pump repair page for more information.

Related Leybold Collections

• Leybold blowers and boosters, RUVAC blowers for diffusion pump backing systems
• Leybold piston pumps, E and DK backing pumps
• Leybold vacuum fluids and greases, LEYBONOL diffusion pump fluids
• All Leybold vacuum pumps
• All diffusion pumps from every brand we carry

Leybold Diffusion Pumps FAQ

1. What does the number in a Leybold DIP model mean?

The number is the nominal pumping speed in liters per second. A DIP 8.000 is rated at about 8,000 l/s and a DIP 50.000 at about 50,000 l/s.

2. What is the difference between a diffusion pump and the LEYBOJET 630?

A diffusion pump gives maximum pumping speed at high vacuum. The LEYBOJET 630 is an oil vapor booster built for high gas throughput in the medium vacuum range, between the diffusion pump and Roots blower ranges.

3. What fluid does a Leybold DIP diffusion pump use?

Leybold recommends LEYBONOL LVO 500 mineral fluid for most DIP and DIJ pumps, or LVO 521 silicone fluid for high and ultra-high vacuum. The LEYBOJET 630 uses LVO 540.

4. What backing pump does a diffusion pump need?

A diffusion pump needs a backing pump that keeps its foreline below the critical backing pressure at full gas load. Large DIP pumps are usually backed by a Roots blower on a rotary vane, piston or dry pump.

5. Why is my diffusion pump backstreaming oil?

Backstreaming usually comes from a missing or overloaded baffle, foreline pressure above the critical limit, heating with poor cooling water flow, or venting the pump while hot. Check the cooling, foreline pressure and baffle first.

Request a Quote on Leybold Oil Diffusion Pumps

Send us your chamber size, required pressure, gas load, flange size and heater supply. We will recommend the right DIP, DIJ or LEYBOJET pump, confirm availability, or quote a rebuild of your existing pump. Contact us or call 831-462-8900.