Available in 4-inch, 6-inch, 250-mm, 10-inch, and 400-mm sizes, the VHS series pumps are the fastest and cleanest diffusion pumps of their size available today. The VHS series patented Bulge Contour doubles gas capture and maintains lower pressure. All VHS series pumps have sight glass/fill and drain assemblies for continuous monitoring and easy maintenance of pump fluid. Finned boilers increase surface area, prolonging pumping fluid life. Full thermal protection and quick-cool coils are also standard. The 4-inch, 6-inch, and 10-inch pumps can be ordered with ASA or ISO flanges, standard or extended cold caps, and a variety of voltages.
| Pumping Speed, Operating Range Pumping Speed, AVS 4.1 (1963) | 2,125 l/s Air, 2,660 l/s He/H2 3,700 l/s Air |
| Maximum Throughput | 2.6 T-l/s (3.5 mbar-l/s) in operating range, 3.5 T-l/s (4.5 mbar l/s) @ 0.01 torr |
| Operating Range | 1.2 x 10-3 to <5 x 10-9 torr (1.6 x 10-3 to <6.5 x 10-9 mbar) |
| Maximum Forepressure | No Load: 0.65 torr (0.85 mbar) Full Load: 0.55 torr (0.72 mbar) |
| Recommended Backing Pump | ≥17 cfm (29 m3/hr) |
| Backstreaming Rate, Standard Cold Cap | < 5.0 x 10-4 mg/cm2/min |
| Warmup Time | 10 minutes |
| Cooldown Time | 10 minutes (with quick cool coil) |
| Fluid Charge | 500 cc – exact fluid charge available |
| Electrical Requirements | 1 ph, 50/60 Hz, 120/208/240 VAC |
| Pump Power | 2200 watts |
| Cooling Water Requirements | 0.25 gpm (50 l/hr) |
| Water Connections | 1⁄8 in. FPT Tee |
