Varian HS-20, Instruction Manual, Page: 16 / 43

SECTION I
INSTALLATION
1-1 GENERAL
Upon receipt, inspect the container for evidence of damage in shipment. Do not discard any evidence of
rough handling. Factory packing provides for maximum protection during shipment. However, the pump
should be inspected immediately and any damage should be reported to the carrier without delay.
Before unpacking and installing the pump, the user should thoroughly familiarize himself with the
contents of this instruction manual, particularly the physical and operating specifications listed in the
following paragraphs, in order to gain a better understanding of the operating principles, limitations,
correct application of the diffusion pump, the hazards involved, and what to do and what not to do in
order to avoid these hazards.
1-2 OPERATING SPECIFICATIONS (See Figure 1-1)
Table 1-1 lists the specifications for all standard models of the HS-20 diffusion pump.
Table 1-1. HS-20 Diffusion Pump Specifications
Model Technical Specifications
Optimum Operating Range 6 x 10
-4
Torr to < 1 x 10
-9
Torr
8 x 10
-2
Pa to < 1.3 x 10
-7
Pa
7.8 x 10
-4
mbar to < 1.3 x 10
-9
Torr
Maximum Pumping Speed 17,500 liters/sec for air
(See Figure 1-1) 21,000 liters/sec for helium
Maximum Throughput 18 Torr-liters/sec
at 1 x 10
-2
Torr 2394 Pa-liters/sec
23.4 mbar-liters/sec
Maximum Forepressure No Load: 0.65Torr; 86.5 Pa; 0.85 millibar
Full Load: 0.55Torr; 73.2 Pa; 0.72 mbar
Backstreaming Rate at Pump Inlet 0.0015 mg/cm2/min
Power Required (approximately) 12 KW, 240/380/480V, 50/60 Hz, 3-phase
Warmup Time 45 minutes
Cooldown Time(using quick cool) 85 minutes (45 minutes)
Fluid Charge 5 U.S. quarts (4.75 liters)
Cooling Water Requirements 1.5 gpm at 60°F to 80°F inlet temperatures
Pressure drop across cooling circuits 15 psi
of cold cap and body in series
Backing Pump Size Recommended 100 cfm for maximum throughput
1-1