Double Stage Oil Vacuum Pump

The 2X / DSVP double stage oil vacuum pump is built for one thing: deep vacuum. Where a single-stage pump reaches the medium-high range, this pump runs two oil-sealed rotary-vane stages in series to reach an ultimate vacuum of ≤6×10⁻² Pa (759.95 mm/Hg) — the level laboratory, refrigeration and degassing work actually requires.

Four models span 240 to 1800 LPM of displacement and 0.55 to 3 kW, with inlet connections from Φ25 to Φ65 mm to match your rig. Every unit is an oil-sealed rotary vane design — repairable, field-serviceable and built to be maintained rather than discarded.

When single-stage is not enough

If your process is defined by how low the pressure must go — evacuating a refrigeration circuit before charging, pulling gas out of an oil or resin, running a vacuum experiment — a single-stage pump simply cannot get there. The second stage is what crosses that threshold, and it is why this pump is specified for the deep-vacuum end of industrial and laboratory work.

It is worth being clear about the numbers, because deep vacuum is quoted on two scales. ≤6×10⁻² Pa is the absolute pressure remaining in the system — the lower the figure, the deeper the vacuum. 759.95 mm/Hg is the same state read on the mercury scale against a ~760 mm atmosphere, so it sits a whisker below a perfect vacuum. Both describe the point this pump pulls down to; the Pascal figure is what a laboratory or refrigeration gauge will show you, and it is an order of magnitude beyond anything a single stage reaches.

All four models hold the same ≤6×10⁻² Pa ultimate vacuum, so select on displacement and inlet size: the 2X-4A gives 240 LPM and the 2X-8A 480 LPM, both on a Φ25 mm inlet; the 2X-15 gives 900 LPM on Φ40 mm; and the 2X-30A gives 1800 LPM on Φ65 mm.

• Mount on a rigid, level base; a double-stage pump must sit true for its oil system to work. Keep ambient below 40 °C.
• Fit an inlet trap or condenser ahead of the pump on wet or vapour-laden duty so moisture never reaches the oil.
• Fit an anti-suckback / non-return valve so oil is not drawn into the rig when the pump stops under vacuum.
• Use short, full-bore, leak-tight inlet lines with the correct Φ connection — every restriction and leak costs you ultimate vacuum.
• Fill with the specified double-stage vacuum oil to the sight-glass line and confirm rotation direction before first start.

The Oil & Vane Service Timeline

A double-stage oil pump reaches its deep vacuum only while its oil is clean and its vanes are true. Follow this cycle and the pump holds ≤6×10⁻² Pa for years; neglect the oil and no oil-sealed pump will hold its rating.

When the Deep Vacuum Slips

A double-stage pump that will not reach ≤6×10⁻² Pa is almost always telling you about its oil, its vanes or a leak. Diagnose in that order.

• Will not reach ultimate vacuum — check for an inlet leak and a restricted line, then contaminated or low oil, then vanes at their wear limit. A single small leak alone will cap the vacuum.
• Oil gone milky — water or vapour has condensed into it. Run warm with the gas ballast open to purge; fit an inlet condenser on wet duty; change the oil if it stays emulsified.
• Ultimate vacuum degrading over weeks — the oil is ageing or the vanes are wearing. Change the oil and inspect the vanes at the same time.
• Oil drawn into the rig — suckback on shutdown under vacuum. Fit an anti-suckback / non-return valve.
• Knocking or loud running — vane or bearing wear; inspect and replace as needed.

• Laboratory & R&D — vacuum experiments, filtration, distillation and analytical rigs needing a stable deep vacuum.
• Refrigeration & HVAC — evacuating moisture and non-condensables from circuits before charging refrigerant; a proper deep vacuum is the difference between a system that lasts and one that fails.
• Degassing — removing dissolved and entrained gas from transformer oils, resins, silicones, adhesives and lubricants.
• Freeze-drying support — backing vacuum for lyophilisation.
• Vacuum impregnation at depths a single stage cannot reach.
• Vacuum metallising & coating roughing duty.