Varian NHS-35 User manual

NHS-35
Diffusion Pump
Instruction Manual
Varian Vacuum Technologies
121 Hartwell Avenue
Lexington, MA 02421-3133
[phone]
(800) 8-VARIAN
Manual No. 6999-01-135
Revision G
April 2000

America
Varian Vacuum Technologies
121 Hartwell Avenue
Lexington, MA 02421,
USA
Tel: [phone]
Fax: [phone]
Toll Free: 1 [phone]
Argentina
Varian Argentina Ltd.
Sucursal Argentina
Av. Ricardo Balbin 2316
1428 Buenos Aires
Argentina
Tel: [phone]
Fax: [phone]
Australia
Varian Australia Pty., Ltd.
6/81 Frenchs Forest Road
Frenchs Forest, NSW 2086
Australia
Tel: [phone]
Fax: [phone]
Brazil
Varian Industria e Comercio Ltda.
Avenida Dr. Cardoso de Mello 1644
Vila Olimpia
Sao Paulo 04548 005
Brazil
Tel: [phone]
Fax: [phone]
Canada
Varian Canada
6705 Millcreek Drive, Unit 5
Mississauga, Ontario L5N 5R9
Canada
Tel: [phone]
Fax: [phone]
China
Varian China Ltd.
Room 1201, Jinyu Mansion
No. 129A Xuanwumen Xidajie
Xicheng District
Beijing 100031
P.R. China
Tel: [phone]
Fax: [phone]
Varian Shanghai
Service Station
716 Yishan Road Shanghai
P.R. China 200233
Tel: [phone]
Fax: [phone]
England
Varian Ltd.
28 Manor Road
Walton-On-Thames
Surrey KT 12 2QF
England
Tel: [phone]
Fax: [phone]
France
Varian s.a.
7 avenue des Tropiques
Z.A. de Courtaboeuf – B.P. 12
Les Ulis cedex (Orsay) 91941
France
Tel: [phone]
Fax: [phone]
Germany
Varian GmbH
Alsfelder Strasse 6
Postfach 11 14 35
64229 Darmstadt
Germany
Tel: [phone]
Fax: [phone]
Hong Kong
Varian Technologies Asia, Ltd.
Rm 2611 Concordia Plaza
New Mandarin Plaza
1 Science Museum Rd.,
Tsimshatsui East, Kowloon
Hong Kong
Tel: [phone]
Fax: [phone]
India
Varian India PVT LTD
1010 Compotent House
7, Nangal Raya Business Centre
New Delhi 110 046
India
Tel: [phone]
Fax: [phone]
Italy
Varian Vacuum Technologies
via Flli Varian 54
10040 Leini, (Torino)
Italy
Tel: [phone]
Fax: [phone]
Japan
Varian Vacuum Technologies
Sumitomo Shibaura
Building, 8th Floor
4-16-36 Shibaura
Minato-ku, Tokyo 108
Japan
Tel: [phone]
Fax: [phone]
Korea
Varian Technologies Korea, Ltd
Shinsa 2nd Bldg. 2F
966-5 Daechi Dong
Kangnam Gu, Seoul
Korea 135-280
Tel: [phone]
Fax: [phone]
Netherlands
Varian Vacuum Technologies
Rijksstraatweg 269 H,
3956 CP Leersum
The Netherlands
Tel: [phone]
Fax: [phone]
Mexico
Varian S.A.
Concepcion Beistegui No 109
Col Del Valle
C.P. 03100
Mexico, D.F.
Tel: [phone]
Fax: [phone]
Singapore
Varian Asia, Ltd.
1123 Serangoon Road
#03-02
Singapore 328207
Tel: [phone]
Fax: [phone]
Spain
Varian Iberica
Avda Pedro Diez 25
28019 Madrid
Spain
Tel: [phone]
Fax: [phone]
Russia
Varian Moscow
19A Khlebny per
121019 Moscow
Russia
Tel: [phone]
Fax: [phone]
Taiwan
Varian Technologies Asia Ltd.,
Taiwan Branch
18F-13 No.79, Hsin Tai Wu Road
Sec. 1, Hsi Chih
Taipei Hsien
Taiwan
Tel: [phone]
Fax: [phone]
Internet Users:
Visit us on the web at:
www.eVarian.com
Representatives in most countries
Sales and Service Offices

WARRANTY
Products manufactured by Seller are warranted against defects in materials and workmanship for
twelve (12) months from date of shipment thereof to Customer, and Seller’s liability under valid war-
ranty claims is limited, at the option of Seller, to repair, replacement, or refund of an equitable portion
of the purchase price of the Product. Items expendable in normal use are not covered by this war-
ranty. All warranty replacement or repair of parts shall be limited to equipment malfunctions which, in
the sole opinion of Seller, are due or traceable to defects in original materials or workmanship. All
obligations of Seller under this warranty shall cease in the event of abuse, accident, alteration, mis-
use, or neglect of the equipment. In-warranty repaired or replacement parts are warranted only for
the remaining unexpired portion of the original warranty period applicable to the repaired or replaced
parts. After expiration of the applicable warranty period, Customer shall be charged at the then cur-
rent prices for parts, labor, and transportation.
Reasonable care must be used to avoid hazards. Seller expressly disclaims responsibility for loss or
damage caused by use of its Products other than in accordance with proper operating procedures.
Except as stated herein, Seller makes no warranty, express or implied (either in fact or by operation
of law), statutory or otherwise; and, except as stated herein, Seller shall have no liability under any
warranty, express or implied (either in fact or by operation of law), statutory or otherwise. Statements
made by any person, including representatives 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 authorized repre-
sentative. Such claims should include the Product serial number, the date of shipment, and a full
description of the circumstances giving rise to the claim. Before any Products are returned for repair
and/or adjustment, written authorization from Seller or its authorized representative for the return and
instructions as to how and where these Products should be returned must be obtained. Any Product
returned to Seller for examination shall be prepaid via the means of transportation indicated as
acceptable by Seller. Seller reserves the right to reject any warranty claim not promptly reported and
any warranty claim on any item that has been altered or has been returned by non-acceptable means
of transportation. When any Product is returned for examination and inspection, or for any other rea-
son, Customer shall be responsible for all damage resulting from improper packing or handling, and
for loss in transit, notwithstanding any defect or non-conformity in the Product, in all cases, Seller has
the sole responsibility for determining the cause and nature of failure, and Seller’s determination with
regard thereto shall be final.
If it is found that Seller’s Product has been returned without cause and is still serviceable, Customer
will be notified and the Product returned at its expense; in addition, a charge for testing and examina-
tion may be made on Products so returned.
3/5/97

i
OPERATION AND MAINTENANCE OF THIS EQUIPMENT INVOLVES SERIOUS RISK. IT IS THE
RESPONSIBILITY OF THE USER TO MAINTAIN SAFE OPERATING CONDITIONS AT ALL TIMES.
VARIAN ASSUMES NO LIABILITY FOR PERSONAL INJURY OR DAMAGE RESULTING FROM
OPERATION OR SERVICE OF THE EQUIPMENT.
Carelessly or improperly operated equipment can cause serious injury or death and/or damage to the
equipment. The emergency and safety procedures in this manual are provided to help users and
qualified persons to operate and service the unit safely. Recommendations are believed to reflect
accepted industry practices in effect on the date of publication of this manual. Special applications
must be reviewed and approved 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 the sole responsibility of users of Varian equipment to comply with all local, state, and federal safety
requirements (laws and regulations) applicable to their system. Employ the services of an industrial
hygienist and/or a qualified chemical safety engineer in order to ensure safe installation and use.
This instruction manual contains information which will assist qualified operators in the operation, and
qualified service engineers to carry out field-servicing the Varian equipment.

ii
SAFE INCORPORATION OF VARIAN DIFFUSION PUMPS INTO VACUUM SYSTEMS IS THE
RESPONSIBILITY OF THE SYSTEMS DESIGNER. TAKE APPROPRIATE ACTION THROUGH
REDUNDANCY, AND/OR OTHER SAFEGUARDS TO PROTECT PERSONNEL AND PROPERTY
FROM THE HAZARDS DESCRIBED BELOW AND IN THE INSTALLATION, OPERATION, AND
MAINTENANCE INSTRUCTION MANUAL. SAFE OPERATION IS THE RESPONSIBILITY OF THE
USING ORGANIZATION AND ITS PERSONNEL. READ THE INSTRUCTION MANUAL AND
UNDERSTAND HOW TO AVOID HAZARDS PRIOR TO OPERATING THE DIFFUSION PUMP. ALL
PERSONS WHO WORK WITH OR ARE EXPOSED TO DIFFUSION PUMPS OR EQUIPMENT
WHICH UTILIZES SUCH PUMPS OR DIFFUSION PUMP FLUID MUST TAKE PRECAUTIONS TO
PROTECT THEMSELVES AGAINST POSSIBLE SERIOUS BODILY INJURY OR DEATH. DO NOT
BE CARELESS AROUND SUCH PRODUCTS.
THESE SHEETS AND THE INSTALLATION, OPERATION, AND MAINTENANCE INSTRUCTIONS
CAN HELP YOU TO OPERATE THIS PUMP 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 systems which utilize diffusion pumps must design out hazards wherever possible; pro-
vide guards, safety features, and interlocks for hazards which cannot be designed out; warn with
respect to hazards which cannot be designed out and which remain after utilizing guards, safety fea-
tures, and interlocks;and lastly, provide procedures and instructions on proper use, servicing, etc., so
as to minimize risk.
WARNING
_____________
Warnings are used when failure to observe instructions or precautions
could result in injury or death to humans.
CAUTION
________
Cautions are used when failure to observe instructions could result in
significant damage to equipment and/or facilities.

iii
THE INSTALLATION, OPERATION, AND/OR SERVICING OR DIFFUSION PUMPS INVOLVES ONE
OR MORE OF THE FOLLOWING HAZARDS, ANY ONE OF WHICH, IN THE ABSENCE OF SAFE
OPERATING PRACTICES AND PRECAUTIONS, COULD POTENTIALLY RESULT IN DEATH OR
SERIOUS HARM TO PERSONNEL.
Hazard Suggested Corrective Action
Loss of utility: water and/or electricity Provide sufficient water and backup power to effect a safe
shutdown under worst case conditions.
Overpressure in foreline Provide an interlock to ensure that the power supply to the
pump heater cannot be activated if the foreline pump is not run-
ning AND/OR pressure in foreline is above 0.5 Torr (66.5 Pa).
Overtemperature Fit temperature sensors and pump fluid level sensors with
feedback to an interlock on the heater power supply.
Insufficient water flow through the Use water flow sensor and feedback to interlock on the heater
main cooling 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 interrupt circuit into heater
power supply.
Positive pressure in pumping system Integrate pressure relief valve in vacuum system.
High voltage (up to 480 V) Prevent personnel contact with high voltages; design and
attach warnings.
Toxicity/Corrosivity Toxic and/or corrosive gases must be vented to a safe
location, ensuring adequate dilution or scrubbing to safe
levels, taking all action required to meet air quality standards.
Explosion Integrate pressure relief valves in all systems using pumps
10 inches or larger in diameter.
Do not use or recommend the use of hydrocarbon-based
pumping oils.

iv
Hazard Suggested Corrective Action
a. Explosion – Operation of the diffusion pump without prior and continuous evacuation (below 0.5
Torr (66.5 Pa)) or coolant and introducing a strong oxidizer (such as air) or explosive vapors or
powders or materials which may react with pumping fluids into a hot (above 300°F or 150°C) pump
can cause an explosion. Such an explosion can violently expel valves and other hardware, slam
open doors that are not designed for appropriate pressure relief, or burst other components of the
vacuum system. Serious injury or death may result from expelled parts, doors, shrapnel, and/or
shock waves.
b. All diffusion pumps are typically cleaned with acetone and alcohol.When combined with air,
oxygen, and other oxidizers, alcohol and most other solvents are very flammable and explosive.
Never permit any trace of these cleaners to remain in or on the pump. Always remove all traces of
alcohol and acetone and other cleaners with clean, dry, oil-free compressed air.
Three elements are required: fuel, oxidizer, and source of ignition. A combination of temperature and
pressure can be a source of ignition. Most diffusion pump fluids except mercury are fuels. Hydrocarbon
oils are more prone to oxidize and explode than synthetic silicone-based oil. Oxidizers 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 combustible mix-
ture to explode.The larger the diffusion pump, the greater the risk of explosion and the greater the risk
of damage and/or injury. Never operate diffusion pumps larger than 10 inches in diameter with hydro-
carbon oils without a full safety analysis for the complete system and application.Never operate any dif-
fusion pump in the following ways because they increase the probability of an explosion.
Prohibited Action Explosion-Causing Condition
Run pump with no cooling water Overtemperature
Run pump with low level of pump fluid Overtemperature
Run pump without proper backing or Overpressure
holding pump
Run pump when not evacuated below Overpressure
0.5 Torr (66.5 Pa)
Admit air to, or rough through, Overpressure plus strong oxidizer
a pump with hot boiler
Open drain or fill plug while pump is Overpressure plus strong oxidizer
under vacuum, especially when it is hot

v
Prohibited Action Explosion-Causing Condition
Contaminate pump with explosive vapors, Lower explosive threshold of gas mixtures
powders, or reactive materials
Remove, defeat, or override safety counter- Overtemperature, overpressure, more
measures such as pressure and thermal combustible mixtures
switches and valve sequencer interlocks
Machine or weld without removing all oil Source of ignition
or solvent residue in pump
Use unsuitable pumping fluid especially Lower explosive threshold of gas mixture
in large pumps
Systems larger than 10 inches must be designed with pressure relief devices to provide safe pres-
sure relief from internal explosions. Always recognize that safety devices can fail or malfunction. Pro-
vide redundant protection by installing devices having different failure modes, failure mechanisms,
and failure causes. Be certain that exhaust duct materials 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 pressurize any part of a vacuum system for test or any other purpose.
Always provide pressure relief when designing diffusion pumps into systems and ensure that pres-
sure relief motion is limited to safe envelopes.Never permit the following:
Prohibited Action Result
Block inlet and vent of liquid nitrogen LN2trap and/or lines burst
trap and lines
Close isolation valves at inlet and discharge Water turns to steam and bursts coils
of main watercooling coils and pump is
reheated
Pressurize pump body Body of pump bursts
Hole through vacuum wall Loss of structural integrity of wall

vi
d. Poisonous and/or Corrosive Compounds – When pumping poisonous, reactive, and/or corrosive
gas, vapors, or chemicals, even proper operation and regeneration will not always ensure that all
hazardous materials have been totally removed. If hazardous gas, vapors, chemicals, or combustible
mixtures are pumped, sufficient quantities may exist during operation or remain after regeneration to
cause severe injury or death. Overheating the pump oil, exposing it to air or reactive materials, or
overpressurizing it above the normal operating range (approximately 1 mTorr (.133 Pa)) will decom-
pose the oil and possibly make it toxic.This is especially true of backstreamed mechanical pump oils
which are more volatile (unstable).Overheating of accidentally introduced or backstreamed mechan-
ical pump oils cannot be protected against by thermal switches which are set for diffusion pump oil.
d. Refer to specific instruction manuals for detailed instructions and precautions. Always vent the
pump and relief valve to a safe location thus ensuring adequate dilution to safe levels, and take all
other action required to meet quality air standards. Always handle pump fluids and hardware with
an awareness of the possible deadly hazards involved and the necessity for great care and atten-
tion to safety precautions.
d. Diffusion pumps are typically cleaned with acetone or alcohol. Acetone, alcohol, and most other
solvents are irritants, narcotics, and depressants, and/or carcinogenic.Their inhalation 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 (up to 480 V) high enough to kill through
electrical shock. Design equipment utilizing these pumps to prevent personnel contact with high
voltages. Securely attach prominent hazard warnings. Personnel should always break the primary
circuit to the power supply when direct access to the heater or wiring is required.
f. Hot Surfaces – Boiler temperatures reach 530°F (275°C) which can cause serious burns when
touched. Always ensure that surfaces have cooled near room temperature before touching them.
g. Hot Coolant and/or Steam – The water used to cool the pump can reach scalding temperatures.
Touching or rupture of the cooling surface can cause serious burns. Water left inside quick cool
coils from previous use will turn to steam when the pump is reheated.This steam must be allowed
to escape without contacting personnel. Whenever possible, design the water system with inter-
lock valves so that power cannot be applied to the pump unless water is flowing in the main cool-
ing coils (not quick-cooling coils).
h. Cold Surfaces – Liquid nitrogen traps cooled by liquid nitrogen are commonly used in diffusion
pumps. Metal surfaces at liquid nitrogen temperature can cause severe frostbite if contacted by
unprotected skin. These surfaces remain cold for some time (at least a half hour) after the liquid
nitrogen has evaporated.

vii
i. Cold Coolant – Liquid nitrogen, a cryogenic liquid, is used in traps.If it is splashed on body tissues
or eyes, it can cause severe frostbite or blindness.The extremely low temperature of liquified nitro-
gen can cause skin damage similar to high temperature burns.Contact with the cold gas evolving
from the liquid may produce the same effect.Delicate tissues, such as the eye tissues, are most
easily damaged by exposure to cold gas or liquid.To minimize the risk of hazardous contact of cold
gaseous nitrogen with any part of the body, wear personal safety equipment recommended for use
with cryogenic materials including face shield, full-sleeved lab coat, and clean, dry gloves which fit
loosely so they can be thrown off quickly if frozen by contact with the gas.
j. Asphyxiation – If a 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 acetone
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-supporting oxygen
which could cause death or serious injury by asphyxiation. Always ensure that cleaning operations
are performed in large, well-ventilated areas.
j. While still hot, the diffusion pump may also contain decomposed and/or overheated pump oils
which can also be an asphyxiant.
k. Large, HeavyWeights – Diffusion pumps larger than 10 inches in diameter require power-
assisted equipment and the use of trained moving/installation personnel in order to avoid
dropping, slipping, and/or overturning the pump thus severely injuring personnel. Check weight
of equipment before lifting and do not stand under equipment being moved.

viii
WARNING
_____________
High voltages (up to 480 V) can kill. Always break the primary circuit to
the power supply before starting to work on the heater and/or its wiring.
WARNING
_____________
Certain gases can become corrosive and toxic when trapped in oil.
Always wear protective gloves when handling dirty pump oil, drain it into
a closable container, and do not breathe the fumes of the oil. Always
use fully self-contained breathing apparatus.
WARNING
_____________
Diffusion pumps are typically cleaned with acetone, alcohol, or other
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 becomes 4 to 5 times heavier than air
and will flow down, settling in tanks, pits, and low 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 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 under the control of the process user and/or
the hardware systems integrator. Frequently, process gases are toxic,
flammable, corrosive, explosive, or otherwise reactive. Since these
gases can cause serious injury or death, it is very important to plumb
the exhaust of the pump to the facility’s hazardous gas exhaust system
which incorporates appropriate filters, scrubbers, etc., to insure that the
exhaust meets all air and water pollution control regulations.

ix
NOTE
________
Always dispose of used or dirty oil properly and in compliance with all
local, state, and federal environmental laws and regulations.
CAUTION
________
Alcohol, acetone, and other solvents degrade O-ring materials reducing
their ability to hold a vacuum. Do not use acetone or other solvents on
O-rings. If necessary to clean O-rings, wipe with lint-free, clean cloth,
wash in detergent and water, or use a small amount of pump oil.
WARNING
_____________
When lifting some Varian diffusion pumps, use power-assisted equip-
ment and trained moving/installation personnel to avoid dropping, slip-
ping, and/or overturning the pump and severely injuring personnel.
Check weight of equipment before lifting and do not stand under equip-
ment being moved.
WARNING
_____________
Hot oils can cause serious burns. Wear protective gloves and long
sleeved, loose fitting, heat resistant garments when draining pump oil.
WARNING
_____________
If hazardous gas, vapors, chemicals, or combustible mixtures are
pumped, sufficient quantities may exist during operation.This pump may
contain decomposed and/or overheated pump oils or poisonous and/or
overheated pump oils or poisonous and/or corrosive process materials
which are highly toxic and also can be an asphyxiant. Proper operation
will not always ensure that all hazardous materials have been removed.

x

Table of Contents
Section Page
Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Section I – Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1-1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1-2 Operating Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1-3 Physical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1-4 Unpacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1-5 Cleaning a New Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
1-6 Utility and System Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
1-7 Adding Pump Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
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 Reassembly the Cold Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3-5 Disassembling and Reassembling the Jet Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3-6 Heater Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
3-7 Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Section IV –Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4-1 Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4-2 Outgassing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4-3 Poor Pump or System Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

List of Illustrations
Figure Title Page
1-1 Speed and Throughput Curves – NHS-35 Diffusion Pump . . . . . . . . . . . . . . . . . . . . . . . 1-2
1-2 Physical Specifications – NHS-35 Diffusion Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
1-3 Section Drawing – NHS-35 Diffusion Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
1-4 Water Cooling Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
1-5 240/400/440V Wiring Diagram – NHS-35 Diffusion Pump . . . . . . . . . . . . . . . . . . . . . . . . 1-10
1-6 380/415V Wiring Diagram – NHS-35 Diffusion Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
1-7 480V Wiring Diagram – NHS-35 Diffusion Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
1-8 Sight Glass Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
3-1 Heater Element Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3-2 External Fittings – Cold Cap Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
List ofTables
Table Title Page
4-1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2