This is the Agilent Varian HS-20, ASA 20 in. (ASA 20 in.) Diffusion Pump O-Ring Kit. O-Ring Kit Contains: 1 Butyl inlet flange O-ring, ASA 20 inch 1 Foreline flange O-ring, ASA 4 inch 8 Viton fill and drain O-rings 4 Viton O-rings 1 Sight glass O-ring 1 Graphite sight glass gasket

This is a replacement Oil Drain Plug. Fits the Agilent Varian HS-20 Diffusion Pump. For location of the oil drain plug see figure #7 (diagram exploded view & parts illustration) below.

This is a replacement Oil Sight Glass. Fits the Agilent Varian HS-20 Diffusion Pump. For location of the sight glass kit see item #6 on (diagram exploded view & parts illustration) below. For pumps built AFTER OCT. 1995.

This is an Agilent Varian replacement graphite gasket for the oil sight glass on HS-20, HS-32, and HS35 diffusion pumps. For location of the sight glass on the pump see item #7 on (diagram exploded view & parts illustration) below. For pumps built after OCT. 1995.

This is a replacement Oil Sight Glass Service Kit. Fits the Agilent Varian HS-20 Diffusion Pump. For location of the sight glass kit see item #6 on (diagram exploded view & parts illustration) below. For pumps built before OCT. 1995.

These Agilent Varian HS-20 diffusion pump cold cap and nut follower (2 each), is part of the jet assembly and is a OEM Agilent Varian replacement part for the HS-20 diffusion vacuum pump. These are original OEM Agilent Varian replacement parts for the HS-20 diffusion pump having part number L8839301, see item #2 in the diagram exploded view & parts illustration below.

These Agilent Varian HS-20 diffusion pump cold cap gasket grommet (kit of 4), is part of the jet assembly and is a OEM Agilent Varian replacement part for the HS-20 diffusion vacuum pump. These are original OEM Agilent Varian replacement parts for the HS-20 diffusion pump having part number L8839301, see item #2 in the diagram exploded view & parts illustration below.

This Agilent Varian HS-20/32, NHS-35 diffusion pump cold cap female coupling, is part of the cold cap assembly and is an OEM Agilent Varian replacement part for the HS-20/32 and NHS-35 diffusion vacuum pump. This is an original OEM Agilent Varian replacement part for the HS-20/32 and NHS-35 diffusion pump having part number 622445026, see item #18 in the diagram exploded view & parts illustration below.

This is a replacement heater nickle wire, 10 AWG, 120 inches long. Fits the Agilent Varian HS-20 Diffusion Pump. For location of the heater wire see figure #10 (diagram exploded view & parts illustration) below. (2 per heater required)

This is a replacement heater nickle wire, 14 AWG, 80 inches long. Fits the Agilent Varian HS-20 Diffusion Pump. For location of the heater wire see figure #10 (diagram exploded view & parts illustration) below. (2 per heater required)

This is a replacement upper thermal (water) switch. Fits the Agilent Varian HS-20/16 Diffusion Pump. Set at 185º F, 85º C. For location of the upper thermal switch see figure #8 (diagram exploded view & parts illustration) below.

This is a replacement lower thermal (boiler) switch. Fits the Agilent Varian HS-20 HS-16 Diffusion Pump. Set at 390º F, 199º C. For location of the upper thermal switch see figure #9 (diagram exploded view & parts illustration) below.

This is a replacement heater insulation blanket. Fits the Agilent Varian HS-20 Diffusion Pump. 3 pieces Cerablanket, 0.50 inch thick. For location of the insulation blanket see item #14 (diagram exploded view & parts illustration) below.

This is a replacement heater element no leads, 200 or 415 V, 2000 W. (1 each) Fits the Agilent Varian HS-20 Diffusion Pump. For Pumps built before May 1990. For location of the heater element see item #11 (diagram exploded view & parts illustration) below. (6 required per pump)

This is a replacement heater element no leads, 480 V, 2000 W. (1 each) Fits the Agilent Varian HS-20 Diffusion Pump. For Pumps built before May 1990. For location of the heater element see item #11 (diagram exploded view & parts illustration) below. (6 required per pump)

This is a replacement crush plate.(1 each) Fits the Agilent Varian HS-20 Diffusion Pump. Should be replaced when heater is replaced. For location of the crush plate see item #12 (diagram exploded view & parts illustration) below.

This is a replacement clamping plate.(1 each) Fits the Agilent Varian HS-20 Diffusion Pump. 6 required per pump. For location of the clamping plate see item #13 (diagram exploded view & parts illustration) below.

This is a replacement heater cover plate. Fits the Agilent Varian HS-20 diffusion vacuum pump. For location of the heater cover plate see item #15 (diagram exploded view & parts illustration) below.

This is a replacement heater element with leads, 200 V, 2000 W. (1 each) Fits the Agilent Varian HS-20 Diffusion Pump. For location of the heater element see item #11 (diagram exploded view & parts illustration) below. (6 required per pump)

This is a replacement heater element with leads, 200 or 415 V, 2000 W. (1 each) Fits the Agilent Varian HS-20 Diffusion Pump. For location of the heater element see item #11 (diagram exploded view & parts illustration) below. (6 required per pump)

This is a replacement heater element with leads, 480 V, 2000 W. (1 each) Fits the Agilent Varian HS-20 Diffusion Pump. For location of the heater element see item #11 (diagram exploded view & parts illustration) below. (6 required per pump)

These are bolts to attach ASA Gate Valves to ASA Diffusion pumps, ASA sizes 6, 8 and 10 inch. One each, size 3/4-10 1-1/4" Length Hex Bolt - Course Thread.