VHS-400 Oil Diffusion Pump

Significance of the Topic

The VHS-400 oil diffusion pump represents a critical component in achieving and maintaining high vacuum conditions across a range of industrial and research applications. High vacuum technology underpins processes in metallurgy, thin-film coatings, heat treatment, and analytical instrumentation, where controlled low-pressure environments are essential for product quality, process efficiency, and reproducible experimental outcomes.

Objectives and Overview of the Data Sheet

This data sheet aims to present the performance features, operational parameters, and practical integration guidelines for the VHS-400 diffusion pump. It provides a concise yet comprehensive reference for engineers, laboratory managers, and vacuum system designers evaluating pump selection, system compatibility, and maintenance requirements.

Methodology and Instrumentation Used

The performance metrics of the VHS-400 were determined using standard vacuum testing protocols with DC704 silicone diffusion pump fluid. Pumping speed and throughput were measured over a defined pressure range and reported in L/s for various gases. Backstreaming rates, warm-up and cool-down times, electrical power consumption, and cooling water requirements were also characterized under controlled laboratory conditions.

Main Performance Characteristics and Discussion

• Pumping speed: 4,500 L/s for air (5,625 L/s for helium/hydrogen), reaching up to 8,000 L/s under AVS 4.1 standards.
• Operating range: from 1.4 × 10⁻³ Torr down to < 5 × 10⁻⁹ Torr.
• Maximum throughput: 6.3 Torr-L/s within the operating range, peaking at 7.5 Torr-L/s at 0.01 Torr.
• Backstreaming rate: < 1.0 × 10⁻³ mg/cm²/min with a standard cold cap.
• Thermal cycle: warm-up in 15 minutes, cool-down in 25 minutes.
• Power and utilities: 4,400 W electrical input (3φ, 50/60 Hz, 208/380/480 VAC) and 0.50 gpm cooling water.
These metrics highlight the pump’s suitability for sustained high-vacuum operation, minimal contamination, and compatibility with a variety of backing pumps (≥ 30 cfm recommended).

Benefits and Practical Applications of the Pump

The robust stainless steel construction and patented bulge contour design improve gas capture efficiency and extend fluid life. The integrated sight glass and fill/drain assembly enable real-time fluid monitoring and simplified maintenance. Typical applications include vacuum furnace environments, metallization of architectural glass, automotive coating processes, and research vacuum systems requiring rapid cycle times and high gas throughput.

Future Trends and Potential Applications

Advances in vacuum pump fluid formulations and surface coatings may further reduce backstreaming and extend maintenance intervals. Integration with smart monitoring systems and IoT-based diagnostics will enhance predictive maintenance and system uptime. Emerging applications in quantum technology, semiconductor fabrication, and advanced materials synthesis will drive demand for higher pumping speeds and lower ultimate pressures.

Conclusion

The VHS-400 diffusion pump offers a compelling combination of high pumping speed, broad operating range, and reliable performance for demanding vacuum applications. Its design features promote long service life, easy maintenance, and seamless integration into industrial and laboratory vacuum systems.

References

Agilent Technologies. VHS-400 Oil Diffusion Pump Data Sheet, 5994-3471EN, August 2024.