Diffusion Pumps

As the worldwide diffusion pump market leader, Varian produces the most comprehensive family of pumps, ranging from 2 in. to 35 in. in diameter, and is the only broad-line, U.S.-based manufacturer.

• High pumping speeds
• High throughput
• High forepressure tolerance
• Low ultimate pressure
• Excellent backstreaming characteristics
• Long-term reliability

	AX-65	HS-2	VHS-4	VHS-6	VSH-250	VHS-10	VHS-400	HS-16	HS-20	HS-32	NHS-35
Previous Model Number		0160	0183	0184	-	0185	-	0164	0165	0167	0169
Speed, l/s (operating range) Air Helium & Hydrogen	65 90	160 200	750 940	1,550 1,930	2,2125 2,660	3,650 4,560	4,500 5,625	6,000 7,500	10,000 12,500	17,300 21,625	28,000 35,000
Maximum forepressure, Torr (mbar) No load Full load	0.75 (1.00) 0.60(0.78)	0.55 (0.72) 0.40(0.52)	0.65 (0.86) 0.55(0.73)	0.65 (0.85) 0.55(0.73)	0.65 (0.85) 0.55(0.72)	0.65(0.85) 0.55(0.72)	0.65(0.85) 0.55(0.72)	0.65(0.85) 0.55(0.72)	0.65(0.85) 0.55(0.72)	0.50(0.65) 0.35(0.45)	0.55(0.71) 0.40(0.52)
Maximum throughput, T-l/s (mbar-l/s) In operating range @ 1 x Torr (1.3 x mbar)	0.19 (0.25) 0.30(0.40)	0.55(0.72) 0.30(0.40)	0.60(0.80) 0.70(0.93)	1.5(2.0) 2.5(3.2)	2.4(3.2) 3.5(4.5)	2.6(3.5) 3.5(4.5)	6.3(8.4) 7.5(10.0)	9.5(11.7)at 8100W 11.5(15.3)at 8100W	12.5(16.7) 18(23.4)	30(40) 35(45.5)	25(33) 35(45.5)
Minimum recommended backing pump for maximum throughput, cfm (/hr)	0.15(0.25)	5.0(8.5)	10(17)	17.0(28.9)	17.0(28.9)	30(51)	30(51)	80(136)	100(170)	300(510)	300(510)
Backstreaming rate at inlet flange mg/c/min (standard cold cap)	2 x 10	1 x 10	5 x 10	5 x 10	5 x 10	5 x 10	1 x10	1.5 x 10	1.5 x 10	7 x 10	5 x 10
Warmup time, minutes	7	15	10	10	15	15	30	45	60	60
Cooldown time, minutes With quick cool coil, where applicable		30	10	10	10	25	25	48	85	180	180
Fluid charge	30cc	100cc	300cc	500cc	1,000cc	1,000cc	3 U.S. qts	3 U.S. qts. (2.8 liters)	3 U.S. qts. (4.7 liters)	3 U.S. qts. (11.3 liters)	3 U.S. qts. (11.3 liters)
Electrical requirements	1ph 50/60 Hz 90/115/165/200V	1ph 50/60 Hz 120/240V	1ph 50/60 Hz 120/208/240V	1ph 50/60 Hz 120/208/240V	1ph 50/60 Hz 120/208/240V	3ph 50/60 Hz 208/240/380/480V	3ph 50/60 Hz 208/240/380/480V	3ph 50/60 Hz 240/415/480V	3ph 50/60 Hz 240/415/480V	3ph 50/60 Hz 240/415/480V	50/60 Hz 240/415/480V
Power, Watts	N/A	450	1450	2200	2200	4400	4400	8100/9600	12,000	24,000	24,000
Cooling water, U.S. gpm (l/hr) at 60-80° F (15-26 °C)	N/A	0.1(20)	0.15(30)	0.25(30)	0.25(50)	0.40(80)	0.40(80)	1.5(300)	1.5(300)	4.0(800)	4.0(800)