York Turbomaster M Series User manual

INSTALLATION, OPERATION AND
MAINTENANCE
SERIES M TURBOMASTER
COMPRESSORS
Supersedes: 220.11-NM1 (366)
Form 220.11-NM2 (602)
SERIES M TURBOMASTER COMPRESSORS
00617VIP

YORK INTERNATIONAL2
FORM 220.11-NM2 (602)
This equipment is a relatively complicated apparatus.
During installation, operation, maintenance or service,
individuals may be exposed to certain components or
conditions including, but not limited to: refrigerants,
oils, materials under pressure, rotating components, and
both high and low voltage. Each of these items has the
potential, if misused or handled improperly, to cause
bodily injury or death. It is the obligation and respon-
sibility of operating/service personnel to identify and
recognize these inherent hazards, protect themselves,
and proceed safely in completing their tasks. Failure
to comply with any of these requirements could result
in serious damage to the equipment and the property
IMPORTANT!
READ BEFORE PROCEEDING!
GENERAL SAFETY GUIDELINES
in which it is situated, as well as severe personal injury
or death to themselves and people at the site.
This document is intended for use by owner-authorized
operating/service personnel. It is expected that this in-
dividual possesses independent training that will en-
able them to perform their assigned tasks properly and
safely. It is essential that, prior to performing any task
on this equipment, this individual shall have read and
understood this document and any referenced materi-
als. This individual shall also be familiar with and com-
ply with all applicable governmental standards and regu-
lations pertaining to the task in question.
SAFETY SYMBOLS
The following symbols are used in this document to alert the reader to areas of potential hazard:
CAUTION identifies a hazard which
could lead to damage to the machine,
damage to other equipment and/or en-
vironmental pollution. Usually an in-
struction will be given, together with
a brief explanation.
NOTE is used to highlight additional
information which may be helpful to
you.
DANGER indicates an imminently
hazardous situation which, if not
avoided, will result in death or serious
injury.
WARNING indicates a potentially haz-
ardous situation which, if not avoided,
could result in death or serious injury.
External wiring, unless specified as an optional connection in the manufacturer’s product
line, is NOT to be connected inside the panel cabinet. Devices such as relays, switches,
transducers and controls may NOT be installed inside the panel. NO external wiring is
allowed to be run through the panel. All wiring must be in accordance with YORK’s pub-
lished specifications and must be performed ONLY by qualified YORK personnel. YORK
will not be responsible for damages/problems resulting from improper connections to the
controls or application of improper control signals. Failure to follow this will void the
manufacturer’s warranty and cause serious damage to property or injury to persons.

FORM 220.11-NM2 (602)
3YORK INTERNATIONAL
NOMENCLATURE
CHANGEABILITY OF THIS DOCUMENT
In complying with YORK’s policy for continuous prod-
uct improvement, the information contained in this
document is subject to change without notice. While
YORK makes no commitment to update or provide
current information automatically to the manual owner,
that information, if applicable, can be obtained by con-
tacting the nearest YORK Engineered Systems Group
office.
It is the responsibility of operating/service personnel
as to the applicability of these documents to the equip-
ment in question. If there is any question in the mind
of operating/service personnel as to the applicability
of these documents, then, prior to working on the equip-
ment, they should verify with the owner whether the
equipment has been modified and if current literature
is available.
Diffuser
Enhancement
M238 A
–7
First Stage
Impeller
Width Designation
Nominal Casing I.D.
Impeller O.D.
Designation
No. of Stages
Multistage Compressor
D
––
Additional Stage
Information
REFERENCE INSTRUCTIONS
DESCRIPTION FORM NO.
CONCRETE BASES 160.71-N1.1
INSTALLATION – OM SYSTEMS 160.71-N1
EFFECTS OF MOISTURE IN REFRIGERANT SYSTEMS 55.60-NM10
VACUUM DEHYDRATION 55.60-NM12
CENTRIFUGAL COMPRESSOR COUPLING ALIGNMENT 160.71-N2

YORK INTERNATIONAL4
FORM 220.11-NM2 (602)
TABLE OF CONTENTS
SECTION 1Description of System and Fundamentals of Operation ................................. 7
SECTION 2Installation .................................................................................................... 11
SECTION 3Operation ...................................................................................................... 14
SECTION 4Service .......................................................................................................... 32

FORM 220.11-NM2 (602)
5YORK INTERNATIONAL
LIST OF TABLES
1 Casing Sizes ..................................................................................................................... 7
2 Approximate Housing Weights For Series M Compressors ........................................... 13
3 Approximate Component Weights For Series M Compressors ..................................... 13
4 Major Compressor Parts ................................................................................................ 19
5 AOP Differential Coltrol Settings ................................................................................... 29
6 COP Low Oil Differential Safety Settings ..................................................................... 29
7 Oil Pressure Switch Tubing Sizing.................................................................................. 30
8 Maintenance Requirements for YORK Multistage Centrifugal Compressors .............. 33
9 Compressor Tools ........................................................................................................... 37
10 Shaft Seal Parts ..............................................................................................................39
11 Typical Shaft Seal Installation “Height” Dimension ....................................................... 40
12 Clearances ..................................................................................................................... 46
13 Screw Sizes for Pulling Drive End Journal Bearing ....................................................... 46
14 General Bolt Torques ..................................................................................................... 47
TABLE PAGE

YORK INTERNATIONAL6
FORM 220.11-NM2 (602)
LIST OF FIGURES
1 Model Series M Turbomaster Compressor ........................................................................ 7
2 Typical Compressor Cross-Sectional View ....................................................................... 9
3 Typical Primary Compressor Gas Flow .......................................................................... 15
4A Balance Piston ................................................................................................................. 17
4B Cut-A-Way View - Model 255 Compressor .................................................................. 17a
5 External Sump Vent Equalizing Lines ............................................................................. 19
6 Exploded View of Atmospheric Shaft Seal ..................................................................... 20
7 Oil Piping Schematic, Applicable for Models Prior to 1970 ............................................ 22
8 Oil Piping Schematic, Applicable for Models After 1970 ................................................ 23
9 Compressor Tools ............................................................................................................ 37
10 Coupling Guard ................................................................................................................ 37
11 Coupling Wrench Application .......................................................................................... 37
12 Loosening the Drive Shaft with Special Wrenches ......................................................... 38
13 Loosening Drive Shaft with Wrenches ........................................................................... 38
14 Shaft Seal Parts ............................................................................................................... 39
15 Assembling Shaft Seal Collar .......................................................................................... 40
16 Seal Ring Assembly ......................................................................................................... 40
17 Removing Drive End Journal Bearing Assembly ............................................................ 42
18 Removing Drive End Oil Seal Assembly......................................................................... 42
19 Exploded View PRV and Oil Seal Assembly .................................................................. 43
20 Oil Reservoir ................................................................................................................... 47
21 Discharge End Bearing and Oil Pump Assembly, Exploded View ................................. 48
22 Checking Alignment of Oil Pump .................................................................................... 49
23 Removing the Oil Reservoir ............................................................................................ 50
24 Exploded View, Oil Reservoir and Oil Seal Assembly .................................................... 51
25 Exploded View, Balance Piston Seal Assembly .............................................................. 52
26 Removing the Pre-Rotation Vane Assembly ................................................................... 53
27 PRV Housing Assembly (Open and Closed Vanes) ....................................................... 53
28 Vane Clamping Fixture .................................................................................................... 54
29 Lifting Top Half of Compressor Casing .......................................................................... 56
30 After Lifting Top Half of Compressor Casing with Sump Housing Removed ............... 56
31 Removing Interstage Labyrinth Seals ............................................................................. 57
32 Diffusers Removed ......................................................................................................... 58
33 Exit Plate Removal .......................................................................................................... 58
34 Removing First Stage Impeller Labyrinth Seal................................................................ 59
35 Rotor ................................................................................................................................ 59
FIGURE PAGE

FORM 220.11-NM2 (602)
7YORK INTERNATIONAL
SECTION 1
DESCRIPTION OF SYSTEM AND FUNDAMENTALS OF OPERATION
GENERAL DESCRIPTION
YORK’s Series M Turbomaster Compressors are de-
signed for compressing various refrigerants, oil field
hydrocarbon gases, CO2, air and chemical vapors.
They are manufactured in three nominal sizes mea-
sured at the inside diameter of the casing. The sizes
are 26, 38, and 55 inches. In addition, a 26 inch cas-
ing with a small diameter high speed rotor is identi-
fied as a 25 inch compressor.
cludes the pressure containing parts and stationary seals.
These compressors can incorporate 1 to 8 stages of com-
pression within a single casing. Series M Turbomaster
compressors may be directly driven by a turbine, mo-
tor, engine, or through a speed increaser/reducer. Ro-
tation must always be driven counter clockwise facing
the shaft end.
FUNDAMENTALS OF OPERATION AND MACHINE
COMPOSITION
This family of compressors has great flexibility in ap-
plication and the materials of construction will vary
based upon the design operating requirements for which
it was selected. Casing material can be cast iron, nodu-
lar iron or cast steel depending upon the design opera-
tion requirements. See Figure 2 for a typical compres-
sor cross-sectional view. Impeller materials can be alu-
minum or stainless steel, or a combination of both to
meet the requirements.
FIG. 1 – SERIES M TURBOMASTER COMPRESSOR
00618VIP 00619VIP
They consist of two major parts groups, the rotor and
the casing. The rotor assembly includes the main shaft,
impellers, and shaft driven oil pump. The casing in-
CASINGS SIZES I.D. 25" 26" 38" 55"
WHEEL B8.25 12.2 18.0 26.7
DIAMETERS
A10.0 14.8 21.9 31.5
(INCHES)
TABLE 1 – CASING SIZES

YORK INTERNATIONAL8
FORM 220.11-NM2 (602)
Description of System and Fundamentals of Operation
The internal stationary seals can be supplied in alumi-
num, bronze, or coated cast iron depending on the appli-
cation. The impeller diameter(s), blade width, and posi-
tion on the rotor can be varied to permit the introduction
of side load connection(s) if required. There can be side
load flows into several different stages and they can en-
ter into the bottom or top half of the compressor casing
as needed to accommodate the application.
Bearings
The compressor is equipped with aluminum sleeve
taper-bore or taper-land journal bearings, with the size
of the suction end bearing being varied as a function of
shaft horsepower. The thrust bearing system can incor-
porate hydrostatic bearings in the active (shaft move-
ment toward coupling) and reverse directions, tilting
pad in the active with hydrostatic in the reverse direc-
tion, or tilting pad in both active and reverse directions.
Temperature Sensors and Proximity Probes
The compressor may be equipped with bearing tem-
perature sensors and/or proximity probes for purposes
of monitoring compressor shaft vibration and/or axial
thrust position.
Seals
The compressor is equipped internally with gas/oil seals
over wind-back spirals on the shaft to control oil from
entering the compressor casing. There is also an atmo-
spheric shaft seal to minimize leakage of oil and pro-
cess gas to the outside where the shaft passes through
the housing. Some leakage from this seal is normal with
the rate being dependent on shaft speed, coupling di-
ameter, and pressure differential across the seal. There
is a provision for that fluid to be directed to an atmo-
spheric drain trap cast into the leg of the main casing.
Bolt Patterns
Due to the varied application of this compressor fam-
ily, there can be differences in the bolting and the pat-
terns of the bolting. There will be more bolts utilized
in the external patterns when the compressor is designed
for a higher design working pressure. There can be
variations on the internal bolting strength and sizing if
the application requires resistance to the effects of cer-
tain corrosion phenomenon. The application drawings
will indicate these special circumstances with special
bolt torque values or notes regarding special identify-
ing features such as “redrawn screws will have green
bolt heads.”
As Built Drawings
It is difficult to define the parameters of a standard mul-
tistage compressor although the typical two stage com-
pressor applied on a water chilling / air conditioning
duty is the most common type.
It is imperative to have the “as built”
drawings for the specific compressor
on hand before ordering spare parts
or attempting to work inside the com-
pressor. Failure to do so could result
in damage to the machine.
SAFETY
It is recommended that all maintenance and service re-
pair work be performed by experienced personnel.
There must be recognition of the potential hazards that
can exist. Those hazards may include (but are not lim-
ited to);
There can be electrical circuitry that
presents an electrocution hazard. Be
sure that the source of all power sup-
plies have been properly isolated and
secured before attempting any service
related activities.
The unit must have the coupling
guards in place and fully attached at
any time the shafts will be rotating. Be
sure that the shafts have stopped com-
pletely and the main power source has
been properly isolated before attempt-
ing any service related work activities
on the system.

FORM 220.11-NM2 (602)
9YORK INTERNATIONAL
FIG. 2 – TYPICAL COMPRESSOR CROSS-SECTIONAL VIEW
LD07317
1

YORK INTERNATIONAL10
FORM 220.11-NM2 (602)
There may be surfaces or fluids with
temperatures that are hot enough to
cause burns or ignite flammable ma-
terials. Care must be taken to protect
against burns or the ignition of flam-
mables.
The system may contain materials
that need to be disposed of in accor-
dance with governing regulations.
Please be sure to follow all pertinent
requirements when disposing of such
materials.
The system contains fluids under po-
tentially dangerous pressures, exer-
cise caution when preparing to service
or remove parts from the system. Be
sure to wear eye protection to avoid
any possible splash hazards.
The compressor contains many close
clearance areas and heavy parts which
can result in situations where fingers
or other extremities may be pinched,
crushed, or even severed. Care should
be taken when lifting or moving any
parts to be sure that any extremities are
free from those dangers.
Certain liquids that are expelled from
the system at atmospheric pressure
may be capable of producing a freeze
hazard to skin or eyes. Eye protection
and gloves should be worn to avoid
potential splash hazards.
Description of System and Fundamentals of Operation

FORM 220.11-NM2 (602)
11YORK INTERNATIONAL
SECTION 2
INSTALLATION
GENERAL
Foundation
These compressors can be furnished with a fabricated
steel base for installation on a suitable foundation of
sufficient strength and rigidity to support the weight of
the operating system. Refer to Figure 2 and Table 3 for
housing and component weights.
Installation Information
Since the equipment will vary to meet the requirements
of a specific installation, it is recommended that the fol-
lowing information be retained for ready reference.
These are furnished with each compressor at the time
of original purchase:
1. A general arrangement drawing.
2. A sectional assembly drawing.
3. A lubrication system schematic diagram.
4. An oil piping drawing.
5. A coupling instruction.
6. An application data sheet.
CONDUCTING THE PRESSURE AND VACUUM / DE-
HYDRATION TESTS
If a pressure test is required perform the following:
Perform all pressure testing and
evacuations before applying insula-
tion of any kind to the system.
Charging of refrigerant should only
occur after completion of the evacua-
tion/dehydration procedure. The re-
frigerant charge should be introduced
into the system as outlined in the ap-
plicable instructions for the job. Cer-
tain conditions can result in very low
temperatures which can be damaging
to equipment/personnel.
1. Conduct the pressure test in accordance with de-
sign parameters outlined in the application data
sheet.
The compressor’s atmospheric shaft
seal may leak excessively if the shaft
seal reservoir has not been filled with
oil.
2. If the atmospheric shaft seal is leaking, charge the com-
pressor shaft seal reservoir with the appropriate YORK
oil (refer to Adding Oil to the Compressor, pages 27
and 28) before continuing the pressure testing.
3. After completion of the pressure testing proceed
with the evacuation/dehydration of the system.
4. Conduct the vacuum test in accordance with the
procedures outlined in Form 55.60-NM12.
INITIAL STARTING – MECHANICAL RUN-IN
Perform the following “bump-in” procedures when
starting any compressor for the first time or after re-
placing bearings and seals.
Seals may settle and contact the shafts
during shipment. A “bump-in” is rec-
ommended to position the floating
seals in their preferred operating lo-
cation. Compressors designed for ha-
locarbon refrigerants or air service can
be mechanically run-in without ex-
ceeding the discharge temperature
limit. The application data sheet will
set the discharge temperature limit
and indicate if a mechanical run-in
cannot be performed.
“Bump-in” Procedure for Turbine and Motor
Driven Systems
Shut down the compressor immedi-
ately if any abnormal conditions are
detected.
2

YORK INTERNATIONAL12
FORM 220.11-NM2 (602)
Installation
Exact speeds are difficult to obtain
with a motor driven system.
1. Start the compressor and bring it up to 25% speed
and then immediately stop the compressor.
2. After shutting down the compressor, allow the
compressor temperatures to stabilize for at least
15 minutes.
3. Repeat steps 1 and 2 at 50% speed, 75% speed,
and 100% speed.
4. Operate the compressor at 100% speed for one
minute while making the following checks:
During the initial operating period,
checks should be made on all me-
chanical parts of the system to be sure
they are functioning properly. They
must include, but are not limited to
the following checks:
A. Check for unusual or excessive vibration or
overheating.
B. In addition to compressor, check motor speed in-
creaser / turbine bearing temperatures carefully.
Compressors that utilize refrigerant
cooled oil coolers may not be oper-
ated if there is no source of coolant
available.
C. Check that the oil cooler(s) is functioning prop-
erly.
D. Check the compressor lubrication system (see
DAILY OPERATION).
E. The compressor discharge temperature must
not exceed the limits specified in the applica-
tion data sheet for the application or the safety
limits of the controls system.
Final Coupling Alignment Check
(Figure 4, Item 16)
This procedure is often referred to as
the “hot check”.
1. After at least six hours of operation at design oper-
ating conditions, or after the system has stabilized
at it’s design operating temperatures, make the com-
plete final coupling alignment check. Refer to the
Final Alignment Check as outlined in the coupling
instruction Form 160.71-N2.
2. Verify the results of the final coupling alignment
check before any effort is made to dowel any of
the components, or finalize the adjustments of the
base frame jackscrews.

FORM 220.11-NM2 (602)
13YORK INTERNATIONAL
TABLE 2 – APPROXIMATE HOUSING WEIGHTS FOR SERIES M COMPRESSORS
CASING ID. STAGES TOTAL WEIGHT CASING ROTOR
(INCHES) (LBS.) (LBS.) (TOP HALF) (LBS.)
(LBS.) A B
2 STAGE 4,000 820 31 20
25 EA. ADD’L 500 100 10 8
2 STAGE 4,000 820 70 60
26 EA. ADD’L 500 100 27 22
2 STAGE 10,500 2,750 230 190
38 EA. ADD’L 1,300 350 90 75
2 STAGE 25,000 5,000 630 500
55 EA. ADD’L 3,000 1,000 250 200
TABLE 3 – APPROXIMATE COMPONENT WEIGHTS FOR SERIES M COMPRESSORS
CASING ID. GRAY IRON DUCTILE IRON STEEL
(INCHES) (LBS.) (LBS.) (LBS.)
PRV HOUSING 350 350 575
25/26 OIL SUMP
HOUSING 650 650 810
PRV HOUSING 900 900 1,230
38 OIL SUMP 1,715 1,715 2,165
HOUSING
PRV HOUSING 2,125 2,125 2,530
55 OIL SUMP 3,520 3,520 4,665
HOUSING
2

YORK INTERNATIONAL14
FORM 220.11-NM2 (602)
Operation
GENERAL
The basic operating principles of all centrifugal com-
pressors are the same, regardless of the size or capac-
ity of the compressor or the number of impellers used.
The following paragraphs describe the path of the re-
frigerant gas flow through a Series M Turbomaster Com-
pressor and the effect upon the gas as it passes from
the suction to the discharge connection(s) of the com-
pressor.
Primary Compressor Gas Flow (Figure 3)
The gas enters the compressor through the suction inlet
connection, and passes through the pre-rotation vanes
to the inlet throat of the first stage impeller.
The high rotative speed of the impellers causes the suc-
tion gas to be drawn into the first stage impeller and is
discharged from the blade tips at high velocity and in-
creased temperature and pressure. The discharge space,
which is formed by the diffuser and the housing, is shaped
to convert some of the velocity energy into pressure
rise before directing the gas from the discharge of the
first stage impeller into the inlet of the second stage
impeller.
From the second stage impeller, the gas passes through
the remaining impellers at high velocity and steadily in-
creasing temperature and pressure. The gas is eventu-
ally discharged into the annular compressor discharge
space, at the oil reservoir end, where it leaves the com-
pressor and enters the discharge line.
A centrifugal compressor does not move a definite quan-
tity of gas under all operating conditions as does a posi-
tive displacement compressor. The ability to compress
is determined by a performance curve which can be
depicted by various parameters, but most frequently head
and flow are used.
SECTION 3
OPERATION
Balance Piston (Figure 4)
Since suction gas enters the first stage impeller (1) at
suction pressure and leaves the high stage impeller (2)
at discharge pressure, the pressure differential becomes
progressively greater between the inlet and the discharge
of each impeller.
The inlet areas of the impellers are only affected by
suction pressure of that stage while the sides of the
impeller are subjected to the higher impeller discharge
pressure of that stage resulting in a net force pushing
toward the impeller inlet.
Because of this pressure difference, an axial thrust
force exists which is toward the suction end of the
compressor.
To maintain the axial thrust within design limits, a bal-
ance piston (3) may be used as a part of the last stage
impeller. Gas leakage past the balance piston is regu-
lated by a “floating” seal ring (4).
The balance piston (3) serves as a rotating partition at
the end of the discharge gas space. The pressure on
the outboard side of this piston is equalized to a lower
stage pressure through one or more internal (5) or ex-
ternal gas equalizing lines (See Figure 5, Item 6). The
compressor diffuser geometry will determine whether
the venting is done internally or externally.
The balance piston (3) is sized so that the pressure dif-
ferential across it reduces the total axial thrust of the
rotor assembly. The balance piston seal (4) is designed
to regulate the leakage into the chamber (6). Elevation
of the pressure differential across the balance piston
above the design will result in increased axial thrust
load toward the suction end of the compressor. The
thrust bearing (7) serves to physically or mechanically
position the shaft (8) and impellers (1 and 2) in the cen-
ter of the diffuser(s) while the thrust load minimizes the
rotor assembly (1, 2 and 3) from shifting axially during
surging and load changes. Extreme elevation of the bal-
ance piston pressure is an indication of a problem that
can result in failure of the thrust bearing (7).

FORM 220.11-NM2 (602)
15YORK INTERNATIONAL
FIG. 3 – TYPICAL PRIMARY COMPRESSOR GAS FLOW
LD07318
3

YORK INTERNATIONAL16
FORM 220.11-NM2 (602)
FIG. 4A – MAJOR COMPONENTS
LD07319
Operation

FORM 220.11-NM2 (602) FORM 220.11-NM2 (602)
YORK INTERNATIONAL YORK INTERNATIONAL
17 17A
FIG. 4B – CUT-A-WAY VIEW - MODEL 255 COMPRESSOR
LD07817
3

FORM 220.11-NM2 (602)
YORK INTERNATIONAL YORK INTERNATIONAL
18B 18
FORM 220.11-NM2 (602)
Operation
External Sump Vent Equalizing Line (Figure 5)
Oil that is returning to the reservoir (1) from the bear-
ing drains contains some additional refrigerant gas af-
ter passing through the bearings and joining with the
buffer gas from the oil seals.
In order to manage that refrigerant gas and the oil reser-
voir pressure, these compressors are equipped with an
external gas line (2) that vents the pressure from the oil
reservoir (1) to the inlet (3) of a lower stage impeller or
appropriate external source.
There is a screen type mist eliminator installed inside
the sump at the inlet (4) of that external gas line (2) to
minimize the opportunity for oil to be carried out with
the vent flow through the line.
An automatic sump vent valve (5) slows the rate at which
the oil reservoir pressure is reduced at start-up. Nor-
mally, the valve is field adjusted to open at a rate that
will reduce oil reservoir pressure without adversely af-
fecting system oil pressure. Valve adjustment may vary
depending on system conditions. The sump vent valve
is typically supplied with an orifice through the seat
which will prevent total isolation of the vent line. Oil
loss through the seals may occur if the compressor is
operated for extended periods with the sump vent valve
closed.
Internal Seals
The internal sealing systems are the backbone of the
compressor’s efficiency and, in some cases, its reliabil-
ity. It is very important to perform the following proce-
dures when evaluating the performance of any sealing
device.
The various internal seal systems used
in the Series M Turbomaster compres-
sor are assembled with clearances that
take into account both thermal effects
and inertia growth characteristics of
the application. For this reason it is
very difficult to tabulate all clearance
values for all applications. Form
160.71-M can be used for two-stage
water chilling application. The infor-
mation in that document should not
be applied to any other application
unless verified on the application data
sheet.
1. Check for proper clearance between all stationary
and rotating parts.
2. Inspect the stationary component’s seal seating sur-
face. There should not be any burrs, ridges, gouges,
etc. where the seal seats in the housing.
Shaft Labyrinths (Figure 4)
The close radial clearance between the
shaft labyrinths (9, Figure 4) and the
rotor shaft (8) reduces gas leakage to
a minimum along the rotor shaft (8).
Gas leakage between stages is kept to a minimum by
means of shaft labyrinths (9) mounted between the (sta-
tionary) diffuser exit plates (10) and the rotor shaft (8).
Balance Piston Seal
Leakage from the high stage impel-
ler discharge area around the balance
piston diameter is minimized by
means of the balance piston seal ring
(4, Figure 4).
The balance piston seal ring system consists of a float-
ing balance piston seal ring (4), spring washer (11), bal-
ance piston cover (12) and an anti-rotation pin (13).
The anti-rotation pin (13) may prevent the seal ring sys-
tem from being damaged due to rotation during a surge
or system upset condition.
Oil Seals (Figure 4)
Oil leakage from the main bearings into the impellers
is prevented by means of the oil seals (14, 15) that
are located on the rotor shaft inboard from the main
bearings.
There are seals that regulate a slight gas leakage (re-
ferred to as buffer gas) into the lubrication system at
the bearing outlets which opposes and prevents oil leak-
age. These seals are located over the area of the main
shaft that is machined with “wind-back” spirals which
are also intended to aid in the prevention of oil loss into
the system if the source of buffer gas should somehow
be reduced.
00620VIP
FIG. 5 – EXTERNAL SUMP VENT EQUALIZING LINES, EXTERNAL BALANCE PISTON VENT LINES

FORM 220.11-NM2 (602)
19YORK INTERNATIONAL
3
TABLE 4 – MAJOR COMPRESSOR PARTS
ITEM DESCRIPTION
1GASKET, 1/32"
2COUPLING, YORK FLEX, COUPLING SYSTEM
3SHAFT, DRIVE, COUPLING SYSTEM
4COVER, BEARING HOUSING
5GASKET BRG. HSG. COVER
6SCREW, CAP, 12 PT. HD.
7SCREW, CAP, HEX HD.
8GASKET SHAFT SEAL COVER 1/16"
9GASKET SHAFT SEAL COVER 1/32"
10 GASKET SHAFT SEAL COVER 1/64"
11 CASING
12 PIN, INSERT
13 COLLAR, SHAFT SEAL
14 PIN, INSERT
15 HOUSING, BEARING
16 BEARING, JOURNAL
17 RING, RETAINING
18 SLEEVE, PRV HOUSING
19 OIL RING, SEAL (SUCTION END)
20 RING, RETAINING
21 SPRING, UNIVERSAL
22 GASKET, PRV SLEEVE 1/16"
23 GASKET, PRV SLEEVE 1/32"
24 GASKET, PRV SLEEVE 1/64"
25 SCREW, CAP, HEX HD.
26 SCREW, CAP, HEX HD.
27 GASKET COMPR. ENDS
28 HOUSING, PISTON RING
29 SCREW, CAP, HEX HD.
30 LOCKWASHER, SPRING
31 RING, PISTON COMPRESSION
32 RING, SEAL (DISCHARGE END)
34 SPRING, UNIVERSAL
35 RING, RETAINING
36 HOUSING SEAL RING
37 SCREW, CAP
38 GASKET, SEAL RING HSG. 1/32"
39 BEARING, THRUST & JOURNAL
40 PIN, INSERT
41 PUMP, CENTRIF. OIL
42 RING, VOLUTE SEAL
43 RING, INT. RETAINING
44 BEARING, REVERSE THRUST
ITEM DESCRIPTION
100 PLUG, PIPE, HEX SOC. CSK. HD. 1/4"
PLUG, PIPE, 3/4" SQ. SOC. CSK. HD.
101 NIPPLE, PIPE
102 SCREW, CAP, HEX HD.
103 WASHER, PLAIN
104 GASKET
105 GASKET, COMPR. ENDS 1/32" THK.
106 GASKET, COMPR. END 1/64" THK.
107 COVER, SHAFT SEAL
108 SPRING, SHAFT SEAL
109 WASHER, SPRING RETAINING
110 SEAL, O-RING
111 RING, SHAFT SEAL
112 SCREW, MACHINE, FLAT HD.
113 RING, RETAINING SEAL
115 DOWEL PIN
116 NUT, HEX
150 ROTOR, ASSEMBLY
151 DIFFUSER, DISK VANE
152 DIFFUSER, VANE ENTRANCE
153 SCREW, CAP, HEX HD.
154 DEVICE, PRE-ROTATION
155 RING, RETAINING
156 RING, LABYRINTH SEAL, EYE SEAL 1ST
157 RING, LABYRINTH SEAL, EYE SEAL 2ND
158 COVER, BAL. PISTON SEAL
159 RING, BAL. PISTON SEAL
160 WASHER, FLAT SPRING
161 SEAL, SHAFT, EXPLODED
184 ROLL PIN
192 ROLL PIN
ITEM DESCRIPTION
45 PIN, INSERT 1/4" X 38"
46 SCREW, CAP, 12 PT. HD., OIL, PUMP
47 HOUSING, OIL PUMP, 1 PC.
48 GASKET, OIL PUMP HSG. 1/32"
49 GASKET, OIL PUMP HSG. 1/64"
50 GASKET, OIL PUMP HSG. .005"
51 SCREW, CAP, 12 PT HD.
52 HOUSING, OIL RESERVOIR
53 CONNECTION, SUCTION, OIL
54 ELBOW, 90 DEGREES, CINCH TYPE
55 BODY, JET PUMP
56 GASKET JET PUMP
57 NOZZLE, JET PUMP
58 ELIMINATOR, MIST, SUMP VENT
59 GASKET, OIL SUMP HSG.
60 COVER, OIL SUMP HSG.
61 GLASS, OIL SIGHT
63 SCREW, CAP, HEX HD.
65 SCREW, CAP, HEX HD.
66 ADAPTER, EQUAL, LINE
67 VENT, INTERNAL TUBE
68 PLUG, PIPE 1/2 HX, SOC. HD.
PLUG, PIPE SQ. SOC. CSK. HD., 3/4"
69 PIUG, PIPE SQ. SOC. CSK. HD., 1"
71 PLUG, PIPE SQ. SOC. HD. 3/4"
72 SEAL, O-RING
73 SEAL, O-RING
74 DISK, 3/8 DIA. X .0598 THK. (26")
DISK, 9/16 DIA. X .098 THK. (38")
DISK, 1-3/16 DIA. X 129 THK. (55")
75 LABYRINTH, SHAFT
80 NAMEPLATE, PUBLICITY
81 NAMEPLATE, PATENT
82 NAMEPLATE, INSTR. (ROTATION)
83 GUARD, CPLG. H.S.
87 NAMEPLATE, DATA
88 SCREW, DRIVE TY. U #4 X 1/4" LG.
94 BUSH., PIPE, 1-1/4 NPTE X 3/4"+
NPTI OUTSIDE HEX
97 SCREW, CAP, HEX HD.
98 PIN, INSERT

YORK INTERNATIONAL20
FORM 220.11-NM2 (602)
Seals that are supplied from a source within the com-
pressor are commonly identified as A-1 seals. Seals in
compressors that utilize an external source of gas as a
buffer are identified as A-4 seals. Source pressure for
A-4 seals should be adjusted to the pressures defined
on the oil flow diagram for the compressor.
Atmospheric Shaft Seal (Figure 6) (Post 1970)
Refrigerant leakage along the shaft to the atmosphere
is prevented by means of a shaft seal assembly (1) which
consists of a rotating cast iron shaft seal collar (2) with
“O-ring” (3) and a stationary spring loaded carbon shaft
seal ring assembly (4), consisting of small helical
springs (5).
These springs keep the carbon shaft seal ring (6) in con-
tact with the rotating shaft seal collar (2).
The shaft seal collar (2) rotates with the shaft (positive
drive through the insert pins in the drive shaft), while
the stationary carbon seal assembly is mounted on the
shaft seal cover (7). Gaskets (8) are used to adjust the
shaft seal installation dimension. These two parts are
lubricated and cooled by the oil circulated through the
seal cavity.
Some leakage of oil and dissolved process gas is nor-
mal and does not indicate a problem. Leakage rates are
dependent upon coupling size, shaft rotational speed,
and oil reservoir/sump pressure. Larger diameter and
FIG. 6 – EXPLODED VIEW OF ATMOSPHERIC SHAFT SEAL
higher shaft speeds will result in more leakage through
the seal faces.
Since oil leakage to the atmospheric side of the shaft
seal is collected in the drain trap, a leaking shaft seal
can be detected by a rapidly filling drain trap and a
corresponding oil level drop in the compressor oil res-
ervoir.
During operation, a small amount of oil dripping past
the seal surfaces is normal. However, if it becomes
necessary to drain the drain trap daily, the shaft seal is
leaking excessively and should be replaced.
Since the seal parts “wear in” to each other during
operation and since it is difficult to determine the
exact location of the leak, it is recommended that the
complete seal assembly (seal ring, seal collars and
“O” rings) be replaced if excessive shaft seal leak-
age occurs. The spring(s) may be reused if it is not
visibly damaged.
If a shaft seal failure occurs, the thrust bearing clear-
ance should be checked. A thrust bearing failure may
have caused the seal failure. The proper thrust clear-
ance is shown in Table 12 for each compressor size. If
a new thrust bearing is required, its clearance should
be adjusted within the limitations shown.
00621VIP
Operation