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Varian HS-20 Instruction Manual Download Page 34

Maintenance

3-5

JET ASSEMBLY

The HS-20 jet assembly consists of several subassemblies. The lower jet assembly consists of the jet
base and stages 3 and 4. A jet shield is provided for the third stage jet. The second stage jet is
secured to the central tube and forms a subassembly. A shield is provided for the second stage jet.
The top of the central tube carries an orifice plug. The top jet spacer passes through this plug and by
a spring-loaded coupling and tie rod secures all stages firmly.

All external and accessible internal surfaces of the jet assembly have been cleaned prior to shipment.

3-5-1

Disassembling the Jet Assembly 

(Refer to Figure 3-2)

a

Disassemble the cold cap water line feedthrough compression seals by removing the nut, the
follower, and the gasket from the side of the pump.

b

Remove the cold cap securing screw and withdraw the cold cap assembly carefully. Be sure
that the seal sleeves are not scored or otherwise damaged.

c

Firmly grasp the jet cap and unscrew it from the coupling assembly.

d

Remove the orifice plug.

e

Withdraw the central tube complete with second stage jet and jet shield.

f

Raise the lower jet assembly which consists of the third stage jet, the jet shield, the fourth
stage jet, and the jet base.

3-5-2

Disassembling the Lower Jet Assembly

a

Remove the third stage shield.

3-5

NOTE

________

Before removing the securing screws in the following step, scribe a ref-
erence mark at the interface to assure that original holes are mated
when reassembled.

b

Remove the securing screws between the third and fourth stage jets. Carefully preserve the
screws. Be sure that the jet spacers are not damaged in handling.

c

Carefully remove the fourth stage jet from the jet base.

d

Clean all parts thoroughly.

Summary of Contents for HS-20

Page 1: ...HS 20 Diffusion Pump Instruction Manual Varian Vacuum Technologies 121 Hartwell Avenue Lexington MA 02421 781 861 7200 Manual No 6999 01 120 Revision G October 2000 ...

Page 2: ...2 Hong Kong Varian Technologies Asia Ltd Rm 2611 Concordia Plaza New Mandarin Plaza 1 Science Museum Rd Tsimshatsui East Kowloon Hong Kong Tel 852 26206173 Fax 852 26206338 India Varian India PVT LTD 1010 Compotent House 7 Nangal Raya Business Centre New Delhi 110 046 India Tel 91 11 5548444 Fax 91 11 5548445 Italy Varian Vacuum Technologies via Flli Varian 54 10040 Leini Torino Italy Tel 39 011 9...

Page 3: ...0 Sales Service and Product Support Press 1 For other departments Press 3 FAX Numbers Order Entry Sales FAX 781 860 5405 Technical Support FAX 781 860 5465 Field Service FAX 781 860 9210 Training Information and Registration FAX 781 860 5479 Copyright by Varian Inc All rights reserved This manual may not in whole or in part be copied photocopied reproduced translated or converted to any electronic...

Page 4: ...tatives of Seller which are inconsistent or in conflict with the terms of this warranty shall not be binding upon Seller unless reduced to writing and approved by an officer of Seller Warranty Replacement and Adjustment All claims under warranty must be made promptly after occurrence of circumstances giving rise thereto and must be received within the applicable warranty period by Seller or its au...

Page 5: ...pproved by an industrial hygienist or chemical safety engineer Varian has no control over the use of this equipment and is not responsible for personal injury or damage resulting from its use The safe use and disposal of hazardous or potentially hazardous materials of any kind is the sole responsibility of the user Observe all WARNINGS and CAUTIONS to minimize the serious hazards involved It is th...

Page 6: ... SAFELY AND EFFICIENTLY READ THEM SPECIAL OPERATING CONSIDERATIONS AND PRECAUTIONS WILL BE FOUND IN THE OPERATION INSTRUCTIONS UNINFORMED OR CARELESS OPERATION OF THIS PUMP CAN RESULT IN POOR PERFORMANCE DAMAGE TO THE PUMP OR OTHER PROPERTY SERIOUS BODILY INJURY AND POSSIBLE DEATH USERS OF THIS EQUIPMENT SHOULD BE ALERT TO TWO LEVELS OF HAZARDS IDENTIFIED BY THE FOLLOWING SYMBOLS Designers of syst...

Page 7: ...y Insufficient water flow through the Use water flow sensor and feedback to interlock the heater maincooling coils power supply Water trapped between inlet and Provide vent or pressure relief valves for both quick cool coil outlet of quick cool coil or liquid and liquid nitrogen trap nitrogen trapped between inlet and outlet of liquid nitrogen trap Loss of ground integrity Incorporate ground fault...

Page 8: ... fuels Hydrocarbon oils are more prone to oxidize and explode than synthetic silicone based oil Oxidizer can be air a strong oxidizer from a leak or can be deliberately introduced in a process or can be inadvertently admitted to the system by operator or process controller error Oxygen and other strong oxidizers are even more dangerous Certain conditions of temperature and pressure can cause a com...

Page 9: ...ls are capable of withstanding the corrosivity temperature and pressure of exhausted products c Pressure Pumps and their components are designed for vacuum service they are not designed to be pressurized which could cause them to burst possibly expelling shrapnel at lethal velocities Serious accidents have been caused by intentional pressurization of vacuum systems and their components Never press...

Page 10: ... and inges tion may produce serious effects Even absorption through the skin can result in moderate toxicity Always ensure that cleaning operations are performed in large well ventilated rooms Use of self contained breathing apparatus may be necessary depending upon the solvent type and vapor concentration in surrounding air e High Voltage Diffusion pumps operate at voltages high enough to kill th...

Page 11: ...large amount of liquid nitrogen is spilled in a small poorly ventilated room or equipment death from suffocation can result All diffusion pumps are typically cleaned with ace tone or alcohol Acetone alcohol and most other solvents are very volatile unstable During cleaning the volatility of these cleaners may permit their gases to displace air and its life support ing oxygen which could cause deat...

Page 12: ...gestion may pro duce serious effects Prolonged or continued contact with the skin will result in absorption through the skin and moderate toxicity Always ensure that cleaning operations are carried out in large well ventilated rooms and wear eyeshields gloves and protective clothing WARNING _____________ Varian has no control over the types of gases passing through this pump These are entirely und...

Page 13: ...h are highly toxic and also can be an asphyxiant Proper operation will not always ensure that all haz ardous materials have been removed WARNING _____________ Hot oils can cause serious burns Wear protective gloves and long sleeved loose fitting heat resistant garments when draining pump oil WARNING _____________ When lifting some Varian diffusion pumps use power assisted equipment and trained mov...

Page 14: ...ding Pump Fluid 1 11 Section II Operation 2 1 2 1 Start up Procedure 2 1 2 2 Shutdown Procedure 2 2 Section III Maintenance 3 1 3 1 General 3 1 3 2 Periodic Inspection 3 1 3 3 Cleaning 3 2 3 4 Disassembling and Reassembling the Cold Cap 3 3 3 5 Disassembling and Reassembling the Jet Assembly 3 5 3 6 Heater Replacement 3 7 3 7 Replaceable Parts 3 11 Section IV Troubleshooting 4 1 4 1 Leakage 4 1 4 ...

Page 15: ...tions 1 7 1 4 200 240 400 430 440 480 V Wiring Diagram HS 20 Diffusion Pump 1 9 1 5 380 415V Wiring Diagram HS 20 Diffusion Pump 1 10 1 6 Sight Glass Assembly 1 12 3 1 External Fittings Cold Cap Assembly 3 4 3 2 20 inch Jet Assembly 3 6 3 3 Jet Coupling 3 8 3 4 Heater Element Assembly 3 9 List of Tables Table Title Page 1 1 Specifications 1 1 4 1 Troubleshooting 4 1 ...

Page 16: ...able 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...

Page 17: ...nal 8 inches min for heater removal Jet Assembly 5 stage Self aligning fractionat ing design with four diffusion stages and one ejector stage Foreline Stacked disk and ring Baffle Cold Cap Water cooled Water 1 4 FPT body and foreline Connections 3 8 quick cool coils Thermal Upper set at 185 F 29 C Switches Lower set at 390 F 93 C Materials Body Mild steel Flanges Mild steel Jet Assembly Aluminum F...

Page 18: ...Installation 1 3 Figure 1 2 Outline Drawing HS 20 Diffusion Pump with ASA Flanges ...

Page 19: ...e been used to protect the internal components c For non critical work after making sure that there are no foreign materials inside the pump it may be charged with fluid and used without disassembly Otherwise it should be disassem bled and cleaned In general cleaning may be required if the expected vacuum level is to be below the 10 6 Torr 000133 Pa range d Check the internal jet assembly It shoul...

Page 20: ...areas thus displacing air which can kill by asphyxiation Use in a large well ventilated room Use of a self contained breathing apparatus may be necessary Acetone alcohol and other solvents are irritants narcotics depres sants and or carcinogenics Their inhalation and or ingestion may pro duce serious effects Prolonged or continued contact with the skin will result in absorption through the skin an...

Page 21: ... the mating flange on the system to the pump inlet is horizontal within plus or minus 1 degree If this condition is not met correct the system before installing the pump The boiler of the pump especially for large pumps must be horizontal to prevent uneven fluid level and avoid local overheating where the fluid level would be too shallow b Prepare inlet O ring seals by wiping them with a clean clo...

Page 22: ...er should not exceed 130 F 54 C b The quick cool coil at the boiler plate must be connected to an open drain and the feed line controlled by a separate water 3 way valve open closed and vent to atmosphere The drain must be below the boiler level so that it is drained completely when the quick cool coil water supply is shut off and the pump is operating Figure 1 3 Cooling Water Connections ...

Page 23: ... switch is mounted on the bottom of the brass strap on the side of the pump The thermal switch should be adjusted with the pump operating as follows a After several hours operation disconnect the lead wires and place an ohmmeter across the terminals of the thermal switch b Turn the adjusting screw until 1 16 of a turn either way will make the contact open or close c Turn the adjusting screw clockw...

Page 24: ...Installation 1 9 Figure 1 4 200 240 400 430 440 480 V Wiring Diagram HS 20 Diffusion Pump ...

Page 25: ...Installation 1 10 Figure 1 5 380 415 V Wiring Diagram HS 20 Diffusion Pump ...

Page 26: ...included in the test Evacuate the entire system with the mechanical pump only Let the mechanical pump reach an ultimate pressure in the system This reading should approximate the value obtained in step a above usually 10 to 50 microns 1 33 to 6 65 Pa If it does not examine for leakage If leakage is suspected follow standard procedures for leak testing These will depend on the type of vacuum gauges...

Page 27: ...ntil the pump has cooled then vent it to atmosphere Remove the plug from the filling port of the pump and install the needed quantity of fluid up to the FULL COLD level indicator on the sight glass see Figure 1 5 The fluid can also be poured in from the pump inlet or foreline d Replace the fill plug with a new Viton gasket Tighten the fill plug using moderate torque 75 inch pounds maximum Lubricat...

Page 28: ...ar bon fluids to ignite or explode when exposed to air air release or admitting air to a pump with a hot boiler permit a strong oxidizer to contact the hot pump oil high above 1 micron 133 Pa inlet pressure insufficient or low level of pump fluid operating pump without cooling water circulating to main water cooling coils operating pump with water trapped in quick cool coil foreign matter in the p...

Page 29: ...nstrumentation e During operation the gas load at the inlet of the diffusion pump should not exceed the maxi mum throughput capability of the pump This means that the pressure at the inlet flange should not except in transient conditions exceed approximately 1 x 10 3 Torr 133 Pa Dur ing operation the discharge or fore pressure must be below the specified tolerable forepres sure 2 2 SHUTDOWN PROCED...

Page 30: ... that the pump is at room temperature before attempting ser vice Serious burns can result if this Warning is not headed Depending on system process poisonous or corrosive compounds may be present when opening the fill or drain Always wear appropriate gloves and clothing and use a self contained breathing apparatus An explosion could occur if the fill or drain is opened when the pump is running or ...

Page 31: ...er solvents When heated sprayed or exposed to high temperature equipment these solvents become flammable and explosive causing serious injury or death Do not use near a high temperature source Ventilate work ing area with a blower and use in large well ventilated room When heated or sprayed solvents also become 4 to 5 times heavier than air and will flow down settling in tanks pits and low areas t...

Page 32: ...igned with the foreline h Check the condition of the O rings and replace them if necessary i Reinstall the pump in the system 3 4 DISASSEMBLING AND REASSEMBLING THE COLD CAP Refer to Figure 3 1 1 To disassemble the cold cap a Remove the female coupling nut follower and gasket located at the end of the cold cap water line on the outside of the pump b Remove the cold cap securing screw which secures...

Page 33: ...Maintenance 3 4 Figure 3 1 External Fittings Cold Cap Assembly NOTE ________ Customer to supply water tubing to be connected to coupling with FPT threads shown above ...

Page 34: ...sket from the side of the pump b Remove the cold cap securing screw and withdraw the cold cap assembly carefully Be sure that the seal sleeves are not scored or otherwise damaged c Firmly grasp the jet cap and unscrew it from the coupling assembly d Remove the orifice plug e Withdraw the central tube complete with second stage jet and jet shield f Raise the lower jet assembly which consists of the...

Page 35: ...Maintenance 3 6 Figure 3 2 20 inch Jet Assembly ...

Page 36: ...e steps in para 3 5 1 in reverse order 3 6 HEATER REPLACEMENT The HS 20 diffusion pump heater array consists of six elements arranged to give as close a balanced load as practical over the three supply phases The heater design employs a long convoluted tubular heating element which is clamped directly to the boiler plate A thin stainless steel membrane with a number of elongated dimples referred t...

Page 37: ...Maintenance 3 8 Figure 3 3 Jet Coupling Note If the jet coupling loosens from the jet rod during disassembly position it so that the top of the jet coupling is flush with the bottom of the orifice plug ...

Page 38: ...Maintenance 3 9 Figure 3 4 Heater Element Assembly NOTE ________ Tighten clamping nuts to 250 in lbs ...

Page 39: ...to hold it in place 8 Screw on the remaining nut finger tight then tighten all nuts evenly up to 250 inch pounds of torque 9 Label the heater leads according to the schematic diagram then run the wires into the con duit and up into the junction box Connect the leads to the terminal strip then replace the elbow cover plate 10 Replace the insulation and heater cover CAUTION Poor clamping resulting i...

Page 40: ...K9050001 Upper thermal switch 185 F K9050002 Lower thermal switch 390 F 656118114 Nickel wire No 14 AWG 648056329 Nickel lug for No 14 AWG 647320025 Heater element with leads 2000W 200V 647320020 Heater element with leads 2000W 240V or 380V 647320035 Heater element with leads 2000W 400V 647320040 Heater element with leads 2000W 430V 647320045 Heater element with leads 2000W 440V 647320030 Heater e...

Page 41: ...Maintenance 3 12 ...

Page 42: ...hroughput capability of the diffu sion pump the diffusion pump will not function and the pumping action will essentially be due to the mechanical backing pump To estimate the gas load isolate the system from all pumps after evacuation and measure the rate of pressure increase The gas load can be estimated as follows V x P Q ______ t where V is the isolated volume P is the pressure rise and t time ...

Page 43: ...eck heaters Low fluid level Add fluid Malfunctioning pump assembly Check and repair or Improperly located jets Damaged replace jet system Inlet pressure surges Incorrect heater input Check and correct Fluid outgassing Condition fluid by operating the pump for a few hours Leak in system ahead of pump inlet Check and correct High chamber Forepressure too high Check for leak in foreline poor contamin...

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