Welch CRVpro 4, 6 og 8 lamellpumper
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Two-stage rotary vane vacuum pumps

Welch Rotary Vane Vacuum Pumps – precision and performance in perfect balance.
Using rotating vanes, these pumps create and maintain stable vacuum conditions – the very foundation of modern vacuum technology. This enables progress across research, industry, and manufacturing.
Welch offers a wide selection of models, from low- to high-capacity solutions, each engineered to meet specific vacuum requirements. The pumps deliver speeds from 2 to 64 CFM (3.4–108.7 m³/h) and achieve vacuum levels down to 0.0003 Torr.
The result is a combination of precision, reliability, and innovation that sets the standard for laboratories, production environments – and beyond.

The CRVpro family includes all the features you’d expect in a direct drive rotary vane pump: gas ballast, forced oil lubrication, anti-suckback mechanism and thermal overload protection.

CRVpro vacuum pumps can be used for applications such as:

  • freeze drying
  • vacuum ovens
  • schlenk line
  • backing turbo molecular pumps
  • degassing
  • vessel/chamber evacuation

Direct drive pumps are not recommended for filtration, aspiration, drying electrophoresis gels, or other applications requiring sustained operation above 30 torr.

See all our Welch vacuum pumps.

Download the CRVpro brochure.

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Order information about CRVpro vane pumps
Order information about CRVpro vane pumps

Vane pumps

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Welch CRVpro 2 to-trinns roterende lamellpumpe

CRVpro2

Max Pumping Speed: 2.5 m3/h (42 l/min)

Ultimate Pressure: 3×10-3mbar

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Welch CRVpro 4 to-trinns roterende lamellpumpe

CRVpro4

Max. Pumping Speed 4 m3/h (67 l/min)

Ultimate Pressure 2×10-3 mbar

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Welch CRVpro 6 to-trinns roterende lamellpumpe

CRVpro6

Max Pumping Speed 6 m3/h (100 l/min)

Ultimate Pressure 2×10-3 mbar

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Welch CRVpro 8 to-trinns roterende lamellpumpe

CRVpro8

Max Pumping Speed 8 m3/h (133 l/min)

Ultimate Pressure 2×10-3mbar

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Welch CRVpro 16 to-trinns roterende lamellpumpe

CRVpro16

Max Pumping Speed 18.3 m3/h (305 l/min)

Ultimate Pressure 3×10-3mbar

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Welch CRVpro 24 to-trinns roterende lamellpumpe

CRVpro24

Max Pumping Speed 26.2 m3/h (436 l/min)

Ultimate Pressure 3×10-3 mbar

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Welch CRVpro 30 to-trinns roterende lamellpumpe

CRVpro30

Max Pumping Speed 33.1 m3/h (551 l/min)

Ultimate Pressure 3×10-3 mbar

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Welch CRVpro 48 to-trinns roterende lamellpumpe

CRVpro48

Max Pumping Speed: 55.7 m3/h (928 l/min)

Ultimate Pressure: 3×10-3 mbar

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CRVpro65

Max Pumping Speed 74.3 m3/h (1238 l/min)

Ultimate Pressure 3×10-3 mbar

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Contact us

Frode Rangset

Frode Rangset

+47 948 26 016
on.tesuhbal@edorf

We would like to hear from you if you have any questions or inquiries about our services and products!

Get an offer

Send melding - Frode eng (#10)

Contact us

Frode Rangset

We would like to hear from you if you have any questions or inquiries about our services and products!

Frode Rangset

+47 948 26 016
on.tesuhbal@edorf

Product Specifications

Areas of Use

Welch CRVpro is a series of two-stage rotary vane vacuum pumps developed for demanding laboratory and industrial environments. With nine models — from CRVpro 2 to CRVpro 65 — the series covers a wide range of vacuum requirements, from simple laboratory applications to heavy industrial processes.

Typical areas of use include:

  • Freeze-drying (lyophilisation) in pharmaceutical and biotechnology industry
  • Vacuum ovens for heat treatment and drying
  • Schlenk lines in chemical research and synthesis
  • Fore-pumping of turbomolecular pumps in advanced vacuum systems
  • Degassing of liquids and materials
  • Evacuation of vacuum chambers and glove boxes
  • Vacuum concentration (evaporation)
  • Mass spectrometry and analytical instrumentation
  • HVAC applications and short path distillation
  • General industrial vacuum processes

Note: Direct-drive pumps are not recommended for filtration, aspiration, drying of electrophoresis gels or other applications requiring continuous operation above 30 Torr.

Advantages

The CRVpro series represents a significant technological advance in rotary vane vacuum pumps — with a focus on longer service life, lower maintenance costs and more stable operation.

Large oil capacity
Chemical vapours that sublimate from the foreline into the pump oil are diluted more effectively in the larger oil reservoir. This reduces oil degradation and chemical attack in the pump.

Cooler operation
Improved air circulation means the pump runs up to 10°C cooler than standard rotary vane pumps. Lower temperature reduces chemical activity and slows oil combustion.

Internal surface treatment
The inner surface of the oil cabinet has PTFE coating and the outer surface of the pump module has black oxide coating. Both extend service intervals by protecting against corrosion and chemical attack.

Low noise
Extremely quiet operation — down to ≤ 50 dB(A) — for undisturbed work in the laboratory.

Forced oil lubrication
Ensures that moving parts are continuously bathed in fresh oil, evens out temperature and extends mechanical service life.

Anti-suckback valve
Prevents oil from being drawn into the application in case of power failure — a critical safety feature for sensitive samples and instruments.

Gas ballast with inert gas option
Minimises entrapped chemicals in the pump oil. Now with the option to connect dry inert gas for even better protection against condensable liquids such as water and acetonitrile.

Dual-voltage motor (CRVpro 2–8)
Motors can be switch-selected between 115V and 240V — making the pumps easy to use globally without modification.

Technical specifications

Read more about our Technical specifications from Welch vacuum pumps.

Functions

The CRVpro series is designed for reliable and long-lasting operation in demanding laboratory and industrial environments.

  • Robust metal construction for long-term use
  • Forced oil lubrication for even temperature and minimal oil degradation
  • Anti-suckback valve – protects application and samples in case of power failure
  • Gas ballast system with inert gas connection (new feature)
  • PTFE coating on inner surfaces of oil cabinet
  • Black oxide coating on pump module – corrosion resistant
  • Labyrinth exhaust baffle system for reduced oil mist emissions and lower noise (except CRVpro 2)
  • Thermal overload protection
  • Compact and modern design adapted to various applications
  • cUL and CE certified
  • Dual-voltage motor IP54 (CRVpro 2–8): switch-selectable 115V/240V
  • Supplied complete with Directorr™ Premium vacuum pump oil, centering rings, clamp rings and motor overload protection

Technical performance curves

Documentation

Datasheet – Welch CRVpro series (PDF)

Key technical data:

  • Pumping speed range: 2.5–74.3 m³/h (42–1,238 l/min) at 50 Hz
  • Ultimate pressure: down to 3×10⁻⁴ mbar (partial)
  • Noise level: ≤ 50 dB(A) (CRVpro 2–8) / ≤ 55 dB(A) (CRVpro 16–30)
  • Voltage: 115V/60Hz or 220–240V/50Hz (CRVpro 2–8 switch-selectable) / three-phase (CRVpro 16–30)
  • Certifications: CE and cUL

Who is CRVpro suited for?

CRVpro is ideal for laboratories and industrial operations that need stable, powerful vacuum with low maintenance. It is particularly well suited for:

  • Pharmaceutical and biotechnology laboratories running freeze drying or vacuum concentration
  • Chemistry research laboratories using Schlenk lines and glove boxes
  • Analytical laboratories with mass spectrometers that need reliable backing pumping
  • Industrial production environments requiring powerful, low-maintenance vacuum capacity
  • Laboratories with vacuum ovens where stable vacuum levels are critical
  • HVAC technicians and short-path evaporation setups
  • Environments where low noise is a requirement (≤ 50 dB(A))

Note: CRVpro is not recommended for filtration, aspiration or drying of electrophoresis gels, or for other applications requiring continuous operation above 30 Torr. For such applications, see our diaphragm vacuum pumps.

About the Manufacturer – Welch

Welch is part of Gardner Denver Thomas GmbH and is one of the world’s leading suppliers of vacuum pumps and systems for laboratories and industry. The company has extensive experience in the development of pump technology and serves customers globally in research, pharmaceuticals, chemistry and industry.

  • EMEA office: Am Vogelherd 20, 98693 Ilmenau, Germany
  • Gardner Denver Thomas GmbH: Livry-Gargan-Str. 10, 82256 Fürstenfeldbruck, Germany
  • Website: www.welchvacuum.com
  • Certifications: CE and cUL

At Labhuset you will find a selection of Welch vacuum pumps adapted to various laboratory purposes.

Order information

Order information about CRVpro vane pumps
Order information about CRVpro vane pumps

Frequently Asked Questions

CRVpro introduces several significant improvements over standard rotary vane pumps: a larger oil reservoir that dilutes chemical vapours more effectively, improved air circulation that keeps the pump up to 10°C cooler, PTFE-coated internal oil cabinet surfaces and black oxide-coated pump module for extended corrosion resistance, and an updated gas ballast system with inert gas connection option. Together these features extend service intervals, reduce oil degradation and deliver more stable vacuum performance over the pump’s lifetime.

Yes. CRVpro is well suited for freeze-drying (lyophilisation) applications. The two-stage design achieves ultimate pressures down to 3×10⁻⁴ mbar, which is within the range required for effective lyophilisation. The gas ballast system with inert gas option provides additional protection against condensable vapours such as water that are generated during the freeze-drying process. CRVpro 16 and above are recommended for larger freeze-dryers with higher pumping speed requirements.

The gas ballast function introduces a controlled amount of air or inert gas into the compression stage of the pump during operation. This prevents condensable vapours such as water and solvents from condensing in the pump oil, which would otherwise cause oil contamination, emulsification and accelerated degradation. Gas ballast should be used whenever the pump is handling wet or solvent-laden gas streams — for example during the initial stages of freeze-drying, evaporation or distillation processes.

The anti-suckback valve automatically closes the pump inlet when the pump stops or power is lost. Without this valve, the pressure differential between the pump and the application could cause pump oil to be drawn back into the vacuum system, contaminating samples, instruments or the application chamber. This is particularly critical in sensitive analytical instruments such as mass spectrometers, and in pharmaceutical production where sample contamination is unacceptable.

CRVpro 2, 4, 6 and 8 are equipped with dual-voltage motors (IP54) that can be switch-selected between 115V/60Hz and 220–240V/50Hz without any modification or rewiring. This makes them fully compatible for use in both European and North American facilities. CRVpro 16 and above require three-phase power supply.

Yes. Labhuset AS offers service and accessories for Welch vacuum pumps in Norway, including Directorr™ Premium vacuum pump oil and replacement parts. Contact Frode Rangset at frode@labhuset.no or +47 948 26 016 for more information.

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