Bubbles are cheap to make and expensive to keep. Entrained air in an epoxy casting cures into voids that weaken the part. Dissolved hydrogen in molten steel turns into porosity that fails inspection. Trapped gas in a pharmaceutical syrup ruins dosing accuracy. Vacuum degassing removes these gases before they become defects, and the pump at the heart of the system decides how thoroughly and how quickly that job gets done.
This guide explains how vacuum degassing works, where a degassing vacuum pump earns its keep, and how to match pump technology to your material, vessel size, and vapor load.
What Is Vacuum Degassing?
Vacuum degassing is the removal of dissolved or entrained gases from a liquid, melt, or paste by lowering the pressure above it. The physics behind it is Henry's law: the amount of gas dissolved in a liquid is proportional to the partial pressure of that gas above the surface. Drop the pressure and the liquid becomes supersaturated, so gas comes out of solution, forms bubbles, expands, and rises to the surface where it is evacuated.
In practice the process is straightforward. The material sits in a chamber or vessel, the pump pulls the pressure down to the process setpoint, bubbles nucleate and burst or are drawn off, and the gas stream is exhausted. What separates a good degassing setup from a frustrating one is whether the pump can hold that setpoint against the gas and vapor load your material releases.
Where Degassing Vacuum Pumps Are Used
Degassing shows up in more industries than most buyers expect:
- Resin, silicone, and epoxy casting — potting compounds, composite layups, and encapsulation all need bubble-free material before curing.
- Metallurgy and metal casting — molten steel and aluminum are degassed to prevent porosity and improve mechanical strength.
- Chemical and polymer processing — solvent devolatilization, monomer stripping, and reactor degassing, often with corrosive or flammable vapors.
- Pharmaceutical and food production — syrups, oils, suspensions, and formulations are degassed for accurate dosing, texture, and shelf life.
- Transformer oil and lubricants — dehydration and degassing restore dielectric strength and extend oil service life.
- Lithium battery manufacturing — electrolyte filling and cell preparation rely on stable, clean vacuum.
Matching Pump Technology to the Job
Oil-Sealed Rotary Vane Pumps: The Workhorse for Chambers and Resin
For small to medium degassing chambers, resin and silicone work, and laboratory duty, an oil sealed rotary vane vacuum pump is usually the most economical answer. InPowerVac single-stage models cover pumping speeds from 4 to 1,200 m³/h at 50 Hz with an ultimate vacuum of 20 Pa or better, which comfortably covers the rough-vacuum range where most casting and potting degassing happens. A gas ballast valve helps the pump tolerate the moisture and vapor that degassing releases.
Dry Screw Pumps: Solvent and Corrosion Duty
When the gas stream carries solvent vapors, reactive chemicals, or anything you do not want mixing with pump oil, a dry screw vacuum pump keeps the compression chamber oil-free and handles condensable loads far better. For aggressive media, a chemical resistant vacuum pump with corrosion-resistant construction, including the titanium alloy oil-free screw variants InPowerVac builds for chemical plants, survives where standard cast iron would not.
Roots Boosters and Systems: Large Vessels, Short Cycles
A large tank degasses on production time, not laboratory time. Once vessel volume grows, a backing pump paired with a Roots blower multiplies effective pumping speed in the working range, and an engineered vacuum pump booster system shortens pump-down and holds pressure against continuous outgassing. This is the standard architecture for metallurgical degassing, large vacuum forming, and central systems serving several stations.
High-Vacuum Specialty Work
A small number of processes, such as degassing ahead of thin-film coating or semiconductor steps, need pressures far below the rough range. Turbo molecular pumps reaching 10⁻⁷ mbar exist for exactly that class of work, backed by a suitable front-stage pump.
Six Selection Criteria That Actually Matter
- Target process pressure, not ultimate vacuum. A pump's nameplate ultimate is measured with a blanked inlet. What matters is whether it holds your setpoint under real gas load.
- Pumping speed sized to volume and outgassing. Estimate chamber volume and the outgassing rate of your material, then choose speed so pump-down time fits your cycle.
- Vapor load handling. Solvents and moisture condense inside oil-sealed pumps unless you use gas ballast; heavy vapor duty argues for a dry pump or a condenser upstream.
- Corrosion compatibility. Match wetted materials and coatings to the chemistry you are pumping, not the chemistry you wish you had.
- Contamination sensitivity. Food, pharmaceutical, and electronics processes often require oil-free pumping to eliminate back-migration risk.
- Utilities and environment. Air-cooled versus water-cooled, noise limits, footprint, and control integration all shape the total installed cost.
Why Manufacturers Source Degassing Pumps from InPowerVac
Zhejiang Yingpa Electromechanical Co., Ltd has built vacuum pumps under the InPowerVac brand since 2000, when its founder entered the field specifically because China's vacuum technology lagged imported brands. Today the company runs two production bases, including a 70,000-square-meter plant in Taizhou added in 2023, with 92 sets of processing equipment, 30 of them imported, and 32 Mazak machining centers dedicated to dry screw pump manufacturing.
Quality control is physical, not paperwork: a material tensile lab, a vacuum testing room, a dynamic balance lab, and three-coordinate measuring machines verify every build. Product details reflect two decades of field feedback, including imported bearings and oil seals, British oil mist filter technology for cleaner exhaust, and an anti-backflow oil design that protects your chamber when the pump stops. Consumables are engineered for long replacement cycles, which is where lifetime cost is actually won.
InPowerVac pumps already serve lithium battery, semiconductor, chemical, pharmaceutical, glass, coating, and packaging lines at companies including Huawei, Samsung, Foxconn, and the Tata Group, and the engineering team routinely builds customized vacuum units for special processes.
Frequently Asked Questions
What vacuum level does degassing need?
Most resin, silicone, and potting degassing works in the rough-vacuum range, well within the 20 Pa ultimate capability of a single-stage rotary vane pump. Metallurgical and solvent-heavy processes typically need deeper vacuum or staged systems. Define your process pressure first, then select the pump.
Should I choose an oil-sealed or a dry pump for degassing?
If your gas stream is mostly air and moisture and budget matters, oil-sealed rotary vane is the proven choice. If you are pumping solvents, corrosives, or anything where oil contamination of the process is unacceptable, go dry.
Can one pump handle a large degassing tank?
Usually not efficiently. Large vessels pair a Roots booster with a backing pump so the combination delivers high speed exactly in the pressure range where degassing happens.
Does InPowerVac build complete degassing systems?
Yes. Beyond individual pumps, the company designs complex vacuum units, booster systems, tank-mounted systems, and customized solutions for special applications.
Not sure which pump fits your degassing process? Send your chamber volume, material, and target pressure to the InPowerVac engineering team for a sized recommendation. Email Winnie@inpowervac.com or call +86 13858602188, and browse the full product range at hi-team.cn.
