A silicone casting shop and a steel mill do not seem to have much in common. One pours liquid rubber into molds by the kilogram; the other taps molten steel by the ton. Yet both lose money to the same invisible enemy: gas dissolved in their product. In the casting shop it appears as bubbles frozen into a cured part. In the mill it appears as hydrogen flaking that can scrap an entire forging. The tool both reach for is a degassing vacuum pump sized for the job. This guide explains how vacuum degassing works, which pump technology fits which process, and what to pin down before you request a quotation.
What Vacuum Degassing Actually Does
Dissolved gas behaves a lot like sugar in coffee: it stays invisible until conditions change. Lower the pressure above a liquid and the equilibrium breaks. The liquid can no longer hold as much gas, so the excess comes out of solution as bubbles. Because the surrounding pressure has dropped, those bubbles expand, rise, and break at the surface, where the pump carries them away.
Every degassing process runs on that single principle, from a desktop resin chamber to a ladle degassing station. What changes from job to job is the scale, the vapor load, and the chemistry of what the pump has to swallow. Those three variables, not the brochure headline, should drive your selection.
Where Degassing Pumps Earn Their Keep
Degassing shows up in more industries than most buyers expect, and each one punishes the wrong pump in its own way:
- Resin, silicone, and epoxy casting. Mold makers and encapsulators pull vacuum on freshly mixed material so bubbles rise out before cure. The result is glass-clear castings, void-free potting, and molds that capture fine surface detail.
- Steel and specialty metallurgy. VD and RH degassing stations strip hydrogen and nitrogen from molten steel to prevent flaking and embrittlement. The gas volumes are enormous and the working pressures are deep, which is why these stations rely on multi-pump systems with boosters.
- Lithium battery production. Electrolyte filling and cell degassing depend on vacuum to wet out electrode coatings and remove trapped gas before sealing. Moisture and solvent vapor go straight into the pump on every cycle.
- Chemical and pharmaceutical processing. Reactor deaeration, solvent degassing, and mobile-phase preparation all pull corrosive or condensable vapors through the pump for hours at a time.
- Food and beverage. Juices, sauces, and process water are deaerated under vacuum to protect flavor, color, and shelf life without heat damage.
- Laboratories. Filtration, aspiration, and solvent degassing are daily duties that demand quiet, clean, reliable vacuum at small scale.
Three Pump Technologies, Three Degassing Personalities
No single pump design wins every degassing job. The three technologies below cover nearly all of it, and the boundary between them is drawn by your vapor load and chamber size.
| Technology | How It Handles Degassing | Best For | Watch Out For |
|---|---|---|---|
| Oil-sealed rotary vane | Deep ultimate vacuum at the lowest cost per cubic meter pumped; oil seals the clearances and carries heat out | Clean, dry chambers: resin and silicone degassing, laboratory duty, packaging machines | Condensable vapors emulsify the oil, so use the gas ballast and change oil on schedule; fit an oil mist filter on the exhaust |
| Dry screw | No oil anywhere in the compression chamber, so solvent and water vapor pass through without contaminating the mechanism or the process | Chemical plants, lithium battery lines, pharmaceutical duty, and any continuous industrial degassing with wet or aggressive vapors | Higher upfront investment; rotor clearance quality decides how long performance holds, so machining capability matters more than catalog promises |
| Roots booster plus backing pump | A Roots blower cannot exhaust to atmosphere alone, but paired with a vane or screw backing pump it multiplies pumping speed at low pressure | Large vessels and fast cycle times: steel degassing, big tanks, and any chamber measured in cubic meters rather than liters | Must be engineered as a matched set with valves, controls, and the right backing pump, not bolted together from separate orders |
For clean casting and laboratory work, an oil sealed rotary vane vacuum pump remains the economical default: InPowerVac's range reaches an ultimate vacuum of 20 Pa or better, with pumping speeds from 4 to 1,200 m³/h across fifteen frame sizes. Where the gas stream turns wet, corrosive, or continuous, a dry screw vacuum pump earns its premium quickly, and for aggressive chemistry a chemical resistant vacuum pump with coated or titanium-alloy wetted parts is the difference between years of service and months of trouble. Large-volume degassing belongs to a properly engineered vacuum pump system built around a Roots booster.
Specifications That Decide Success
Bring this checklist to any supplier conversation and you will separate engineering partners from catalog resellers:
- Working pressure, not ultimate vacuum. Degassing happens at a process pressure, not at the pump's best-case number. Ask for the pumping-speed curve and size the pump where you will actually run it.
- Vapor load. Estimate how much solvent or water the process releases per cycle. That answer chooses between oil-sealed and dry, and decides whether you need gas ballast or an upstream condenser.
- Chamber volume and cycle time. Pump-down time is volume divided by speed at your working pressure. If the cycle time matters commercially, model it before you buy.
- Atmosphere classification. Where degassing vents flammable vapor, specify an explosion proof vacuum pump build rather than hoping the room ventilation copes.
- Cooling method. Air cooling installs anywhere with no water loop; water cooling holds steadier temperatures through hot, continuous duty. Match it to your duty cycle, not your preference.
- A year of ownership. Ask what consumables the pump eats annually, vanes, oil, filters, seals, and how fast replacements ship. The cheapest pump to buy is rarely the cheapest pump to own.
Size on the curve, not the brochure. A pump quoted only by ultimate vacuum is like a truck quoted only by top speed. Ask every supplier for the pumping-speed curve at your working pressure; the honest ones send it without being asked twice.
The Manufacturer Behind the Pump
Degassing duty is hard on pumps, which makes the builder's machining and testing depth worth checking. Zhejiang Yingpa Electromechanical Co., Ltd, the company behind the InPowerVac brand, has manufactured vacuum equipment since 2000. It operates two production bases, including a 70,000-square-meter plant in Taizhou added in 2023, and runs 92 sets of processing equipment, 30 of them imported. For dry screw manufacturing specifically, 32 Mazak machining centers are dedicated to rotor production, the single operation that decides whether a dry pump holds its clearances for years or loses performance within months. Inspection capacity covers three-coordinate measurement, dynamic balancing, dedicated vacuum test rooms, and a materials laboratory, so every unit is verified before it ships.
The details matter on oil-sealed machines too: imported bearings and shaft seals, British oil mist filter technology, and an anti-backflow design that protects the chamber when the pump stops under vacuum. The customer list carries its own weight: Foxconn, Huawei, Samsung's operations in Korea and Vietnam, India's Tata Group, Aoyama Group, and Russian National Energy. These are organizations that audit suppliers before signing and reorder only when the equipment holds up.
Get a Matched Model and a Quotation
Send the engineering team your chamber volume, process material, target pressure, and cycle time, and they will return a matched model with a quotation. Reach Winnie directly at Winnie@inpowervac.com or +86 13858602188, browse the full range on the products page, or use the contact page for customized systems built around a special process.
