Degassing Vacuum Pump Guide: How to Choose the Right Pump for Your Process

How Vacuum Degassing Actually Works

The physics behind degassing is described by Henry's law: the amount of gas dissolved in a liquid is proportional to the partial pressure of that gas above the liquid. Lower the pressure in the headspace of a chamber, and the dissolved gas becomes unstable — it comes out of solution as bubbles, rises to the surface, and is drawn away by the vacuum pump. Hold the pressure long enough, and the material leaves the chamber essentially gas-free.

The same principle applies whether you are degassing silicone rubber in a tabletop chamber or hydrogen out of molten steel in a ladle station. What changes from one process to another is everything else: viscosity, temperature, the volume of vapor released, and how deep a vacuum the material actually needs. Those variables are exactly what should drive your pump selection.

Where Vacuum Degassing Is Used

Degassing shows up in far more industries than most buyers expect:

• Resin, epoxy, and silicone casting — pulling entrained air out before pouring, so castings cure without voids, fisheyes, or cloudy surfaces.
• Adhesives, coatings, and inks — removing micro-bubbles that cause pinholes, weak bonds, and surface defects.
• Metallurgy and metal casting — stripping hydrogen from molten steel and aluminum to reduce porosity and improve mechanical properties.
• Transformer and lubricating oils — removing moisture and dissolved air to restore dielectric strength and slow oxidation.
• Pharmaceutical and food production — degassing solutions, syrups, and edible oils for accurate dosing, consistent texture, and longer shelf life.
• Chemical processing — stripping dissolved gases and light volatiles from solvents, monomers, and polymers before reaction or packaging.

InPowerVac pumps already run in lithium battery, semiconductor, new materials, glass, surface coating, chemical research, packaging, medical, and pharmaceutical plants — sectors where a degassing step is often part of the daily routine rather than a specialty operation.

Six Criteria That Should Drive Your Selection

1. Ultimate pressure vs. what the process really needs

Not every degassing job needs deep vacuum. Trapped air in resins and silicones releases readily at rough vacuum levels, while moisture, solvents, and dissolved gases in oils or metals demand a much lower ultimate pressure. Buying more vacuum than the process requires costs money up front and in operation; buying too little means bubbles that never fully release. Start from the material and work backward to the pressure range.

2. Pumping speed and chamber volume

Pump-down time is governed by a simple relationship: the larger the chamber and the faster the required cycle, the more pumping speed you need. A common rule of thumb is t ≈ (V ÷ S) × ln(p₁ ÷ p₂), where V is chamber volume, S is pumping speed, and p₁/p₂ are the start and target pressures. For orientation, InPowerVac's oil-sealed rotary vane line alone covers roughly 4 to 1,200 m³/h, so both small degassing chambers and large industrial tanks can be sized from one product family.

3. Vapor and condensable load

Degassing rarely moves dry air alone. Resins, solvents, and warm oils release vapor that will condense inside the pump and contaminate the oil if the system is not designed for it. An operating gas ballast, an inlet condenser or cold trap, or a dry pump that tolerates vapor without any oil to ruin — one of these answers has to be in the design from day one.

4. Chemical compatibility

Solvent vapors and corrosive process gases attack standard pump internals. If your process strips volatiles out of chemicals or coatings, specify corrosion-resistant construction from the start. InPowerVac builds chemical resistant vacuum pump models, including TA10 titanium alloy oil-free screw pumps, precisely for this kind of duty.

5. Oil-sealed or dry: cleanliness vs. cost

An oil sealed rotary vane vacuum pump remains the economical workhorse for rough and medium vacuum degassing — deep ultimate pressure, simple maintenance, low purchase cost. Where the process cannot tolerate any oil back-streaming, or where the gas load is dirty, wet, or corrosive, a dry screw vacuum pump earns its higher price through clean operation and long intervals between overhauls.

6. Cooling and duty cycle

A pump that degasses one batch per hour lives a different life from one holding vacuum on a 24/7 production line. Continuous industrial duty favors a water cooled vacuum pump design with stable temperature control, while intermittent laboratory or workshop use can often rely on air-cooled machines. Match the cooling concept to the real duty cycle, not the best-case one.

Pump Technologies at a Glance

• Rotary vane pumps (single and two stage) — the default choice for resin, oil, and general chamber degassing. InPowerVac models span ultimate pressures down to the ≤20 Pa class with a wide speed range.
• Dry screw pumps — clean, contact-free compression for chemical, pharmaceutical, and vapor-heavy degassing where oil contamination is not acceptable.
• Roots-type boosters — a vacuum assist pump staged on top of a backing pump multiplies pumping speed for large chambers, short cycles, and steel degassing stations. Remember that a Roots stage always needs a suitable backing pump; it cannot exhaust to atmosphere on its own.
• Engineered systems — when the process needs more than a bare pump, a dry vacuum pump system combines backing pump, boosters, condensers, and controls in one matched unit.

Selection Mistakes Worth Avoiding

The most common error is sizing the pump from chamber volume alone while ignoring the outgassing rate of the material — a small chamber full of warm, freshly mixed resin can outgas far more than a large tank of cold oil. Close behind is forgetting the vapor load, which shows up weeks later as emulsified oil and a pump that no longer reaches its rated ultimate pressure. Other recurring mistakes: shopping by the datasheet's ultimate vacuum instead of the working point on the pumping-speed curve, omitting a condenser where one is clearly needed, and running a Roots booster without a correctly sized backing pump. Each is cheap to avoid at the specification stage and expensive to fix afterward.

Why Buyers Work with InPowerVac

Zhejiang Yingpa Electromechanical Co., Ltd has built vacuum equipment under the InPowerVac brand since 2000, and vacuum is all the company does. Two production bases in Zhejiang and Hebei operate 92 sets of processing equipment, 30 of them imported, including 32 Mazak machining centers dedicated to dry screw pump manufacturing. Quality is verified in-house with a materials tensile and physics lab, a vacuum testing room, dynamic balancing equipment, and three-coordinate measuring machines.

The design details matter in degassing duty. Imported bearings and oil seals keep pumps reliable over long runs; British oil mist filter technology keeps the exhaust clean; an anti-backflow oil design protects your chamber and product if the pump stops under vacuum. Consumables run on long replacement cycles, which keeps the cost per operating hour low. That combination is why manufacturers such as Foxconn, Huawei, Samsung, Tata Group, Aoyama Group, and Russian National Energy source vacuum equipment from InPowerVac.