ChemVak WH-4SN Single-Stage Rotary Vane Oil-Sealed Vacuum Pump

Overview

The ChemVak WH-4SN is a compact, single-stage rotary vane vacuum pump engineered for reliable and stable operation in general laboratory vacuum applications. Utilizing the proven principle of positive displacement via rotating vanes within an eccentrically mounted rotor, the WH-4SN achieves consistent pumping performance across variable load conditions—including moderate levels of water vapor and mildly aggressive vapors. Its oil-sealed design ensures high volumetric efficiency and robust sealing between compression stages, enabling rapid attainment of ultimate vacuum (2.5×10⁻² mbar) while maintaining mechanical stability over extended duty cycles. Designed as a standalone roughing pump or as a forepump for high-vacuum systems—such as turbomolecular pumps or diffusion pumps—the WH-4SN meets the operational demands of routine vacuum processes without requiring complex infrastructure or auxiliary cooling.

Key Features

• Compact footprint and lightweight construction (7 kg), facilitating benchtop integration and portability across shared lab spaces.
• Integrated gas ballast valve enables continuous removal of condensable vapors (e.g., water, solvents), minimizing oil contamination and extending service intervals.
• IP54-rated sealed motor with thermal overload protection ensures safe, uninterrupted operation under typical ambient lab conditions (15–35°C).
• Low-oil-mist design reduces airborne hydrocarbon particulates, supporting compliance with indoor air quality guidelines in enclosed laboratory environments.
• Circular polycarbonate oil sight glass provides clear, parallax-free monitoring of oil level and clarity—critical for preventive maintenance and vacuum integrity assurance.
• Acoustically optimized housing and precision-balanced rotor assembly limit operational noise to <68 dB(A), meeting ISO 3744 requirements for laboratory-grade equipment.
• Corrosion-resistant internal coatings and nitrile elastomer seals enhance compatibility with common organic solvents and humid process streams.

Sample Compatibility & Compliance

The WH-4SN is suitable for non-hazardous, non-explosive, and non-radioactive gaseous media. It is not intended for use with oxygen-enriched atmospheres, halogenated compounds, strong oxidizers, or highly polymerizing vapors. When operated within its specified ambient temperature and humidity range, the pump complies with IEC 61000-6-3 (EMC emission standards) and UL 61010-1 (safety requirements for electrical equipment for measurement, control, and laboratory use). Its mechanical architecture supports GLP-aligned maintenance logging; oil change records, gas ballast usage logs, and vacuum decay tests may be documented per institutional SOPs. While not certified to ISO 8573-1 Class 0 for oil-free air, its low mist output satisfies Class 3–4 particulate limits for general-purpose vacuum lines serving analytical instrumentation.

Software & Data Management

The WH-4SN operates as a stand-alone electromechanical device without embedded digital controls or connectivity interfaces. All operational parameters—including inlet pressure, runtime, and oil condition—are monitored manually using the integrated sight glass and external vacuum gauges (e.g., Pirani or capacitance manometers). For laboratories implementing electronic lab notebooks (ELNs) or LIMS, pump usage metrics can be logged via timestamped entries referencing batch numbers, process steps, or instrument IDs. Optional analog vacuum sensors (0–10 V or 4–20 mA output) may be installed downstream to feed real-time pressure data into SCADA or LabVIEW-based monitoring systems—enabling traceable vacuum history aligned with FDA 21 CFR Part 11 audit trail requirements when paired with validated software layers.

Applications

• Rotary evaporation and short-path distillation under reduced pressure
• Vacuum-assisted filtration (e.g., Büchner or Hirsch funnels)
• Freeze-drying (lyophilization) pre-evacuation and primary drying support
• Leak testing of sealed components using pressure-rise or helium sniffing methods
• Thin-film deposition systems requiring stable rough vacuum before high-vacuum stage activation
• Encapsulation and vacuum impregnation of porous materials
• Gas sampling and sample preparation for GC, MS, or FTIR analysis

FAQ

Can the WH-4SN be used as a forepump for turbomolecular pumps?
Yes—it is commonly deployed as a forepump for turbomolecular and cryogenic vacuum systems, provided the inlet pressure remains above the turbo’s maximum allowable forepressure (typically ≤0.5 mbar).

What type of vacuum pump oil is recommended?
ChemVak recommends ISO VG 100 mineral-based or synthetic hydrocarbon oils meeting DIN 51506 VDL specifications. Avoid silicone or ester-based oils unless explicitly approved by the manufacturer.

How often should the oil be changed?
Under normal laboratory use (≤4 hrs/day, low moisture load), oil replacement is advised every 500 operating hours or semiannually—whichever occurs first. More frequent changes are required with high water vapor exposure.

Is the WH-4SN compatible with continuous-duty operation?
Yes—the motor and bearing system are rated for continuous operation at ambient temperatures up to 35°C, provided adequate ventilation and oil level are maintained.

Does the pump include a vacuum gauge?
No—vacuum measurement requires an external gauge. The WH-4SN features only a visual oil level indicator; pressure readout must be added separately per application requirements.