Instruction manual

VHS-4, VHS-6 and VHS-250 Diffusion Pumps
20
D R A F T 6 / 1 8 / 1 3
Backstreaming Rate at Pump Inlet 5x10
−4
mg/cm
2
/minute (with std cold cap)
Electrical Requirements 120, 208, 240; 50/60 Hz; single phase
Warm-up Time 10 minutes
Cooldown Time
(using Quick Cool Coil)
10 minutes
Fluid Charge VHS-4: 300 cc
VHS-6 and VHS-250: 500 cc
Cooling Water Requirements Maximum inlet temperature – 60/80 °F (15 - 26 °C)
Maximum outlet temperature at foreline – 120 °F (48.9 °C)
Flow rate – VHS-4: 0.15 gpm
VHS-6 and VHS-250: 0.25 gpm
Pressure drop across coils VHS-4: 4 psi
VHS-6 and VHS-250: 15 psi
Backing Pump Size VHS-4: ≥ 10 cfm for maximum throughput
VHS-6 and VHS-250: 17 cfm for maximum throughput
Recommended Jet Assembly 4-stage, self-aligning, stainless steel
Foreline Baffle Stacked half moon
Cold Cap Nickel-plated copper
Water Connections 1/8" FPT
Thermal Switches Manual reset at 300 °F (149 °C)
Environmental Maximum ambient temperature 113 °F (45 °C)
Installation Indoor use, Installation Category 2, Pollution Degree 2
Altitude 6562’ (2000 m)
Table 1-1 Pump Operational Specifications (Continued)