Tuthill KINNEY KC Series User manual

KINNEY®
Two-stage, Rotary Piston Vacuum Pump
KC™ SERIES
Models
KC5 KC8 KC15
OPERATOR’S MANUAL
Manual 1807 0115 ENG
Tuthill Vacuum & Blower Systems tuthillvacuumblower.com 800.825.6937
WARNING: Do Not Operate Before Reading Manual
Operator’s Manual: Tuthill KC™ Series Two-stage, Rotary Piston Vacuum Pump

2
SAFETY PRECAUTIONS FOR ROTARY PISTON PUMPS
Please read the following safety information on this page before operating your vacuum pump.
NOTICE
The above safety instruction tags were permanently affixed to your pump prior to shipment.
Do not remove, paint over or obscure in any manner.
Failure to heed these warnings could result in serious bodily injury
to the personnel operating and maintaining this equipment.
• Do not operate the pump without the belt guard properly attached. Disconnect the pump motor from the electrical supply
at the main disconnect before removing the belt guard. Replace the belt guard before reconnecting the power supply to
the pump motor. Operating the pump without the belt guard properly installed exposes personnel in the vicinity of the
pump to risk from rotating drive components.
• Do not operate the pump with oxygen-enriched gas (greater than 20% by volume) in the suction line, unless the pump has
been prepared with an inert fluid suitable for the application. Pumping oxygen-enriched gases with mineral oil or other
non-inert fluids can cause fire or explosion in the pump, resulting in damage or serious bodily injury.
• Take precautions to avoid prolonged or excessive exposure to oil mist or process materials emanating from the discharge
of the pump.
• Do not allow the pump to discharge into a closed, or inadequately ventilated room. Always use a discharge oil mist
eliminator unless the pump discharge is discharged to outside atmosphere. Laws and ordinances may pertain to your
local area regarding discharge of oil mist or vapor to atmosphere. Check local laws and ordinances prior to operation of
the pump with discharge to outside atmosphere. Venting of the discharge of an oil mist eliminator to outside atmosphere
is highly recommended.
• Do not restrict the pump discharge in any way, or place valves in the discharge line. The vacuum pump is a compressor
and will generate high pressures without stalling the motor when operated at low suction pressures. Excessive pressure
could cause damage or serious bodily injury.
• Disconnect the pump motor from the electrical supply at the main disconnect before disassembling or servicing the pump.
Make sure pump is completely reassembled, the belt guard is properly installed, and that all fill and drain valves are
installed and closed before reconnecting the power supply. Accidental starting or operation of the pump while maintenance
is in progress could cause damage or serious bodily injury.
• Lift pump only by the lifting lugs supplied with the pump. DO NOT lift equipment attached to pump by the pump lifting lugs.
• Do not touch hot surfaces on the pump. In normal operation at low pressures, surface temperatures will not normally
exceed 180° F (82° C). Prolonged operation at 200 Torr (267 mbar a) may cause surface temperatures as high as 220°
F (104° C)
!WARNING
DO NOT OPERATE
WITHOUT BELT
GUARD
DO NOT VALVE OR RESTRICT PUMP
DISCHARGE OPENING.
USE OIL MIST ELIMINATOR WHEN
OPERATING PUMP, ENSURE ADEQUATE
VENTILATION WHEN DISCHARGING INDOORS
REFER TO MANUAL SAFETY INSTRUCTIONS.
!CAUTION

3
TABLE OF CONTENTS
SECTION PAGE
SAFETY PRECAUTIONS AND WARNINGS 2
INTRODUCTION 4
OPERATING DATA 4
DESCRIPTION 5
General 5
Pump Components 5
Operating Cycle 5
Sealing and Lubrication 6
Oil Types 6
Specifications Table 6
INSTALLATION 7
Mounting 7
V-Belt Drive 7
Discharge Piping 7
Vacuum Piping 7
Vacuum Gauges 8
Electrical Connections 8
General 8
Filling the Pump with Oil 8
Prestart Checks 9
OPERATION 9
Starting the Pump 9
Stopping the Pump 9
Gas Ballast 10
Special Refrigeration Service Units 10
MAINTENANCE 11
Pump Periodic Maintenance 11
Changing the Oil 11
Flooding 11
Oil Mist Eliminator 11
Stalling 12
TROUBLESHOOTING 13
Checking Pump Performance 13
Pump Leaks 14
Checking Process Equipment 14
Process Equipment Leaks 14
Leak Checking Techniques 15
Oil Contamination 15
Discharge Valve 15
Shaft Seal 16
DISASSEMBLY 17
REASSEMBLY 18
REPLACEMENT PARTS 19
PARTS LISTS & EXPLODED VIEWS 20
KC-5/KC-8 20, 21
KC-8C 22, 23
KC-15D 24, 25
KC-15L 26, 27
WARRANTY STATEMENT 28

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INTRODUCTION
CONGRATULATIONS on your purchase of a new KINNEY®KC™ Two-stage, Rotary Piston Vacuum Pump from Tuthill
Vacuum & Blower Systems. Please examine the pump for shipping damage, and if any damage is found, report it
immediately to the carrier. If the blower is to be installed at a later date make sure it is stored in a clean, dry location
and rotated regularly. Make sure covers are kept on all openings. If blower is stored outdoors be sure to protect it from
weather and corrosion.
KINNEY KC vacuum pumps are built to exacting standards and if properly installed and maintained will provide many
years of reliable service. We urge you to take time to read and follow every step of these instructions when installing and
maintaining your blower. We have tried to make these instructions as straightforward as possible. We realize getting any
new piece of equipment up and running in as little time as possible is imperative to production.
WARNING: Serious injury can result from operating or repairing this machine without first reading the service manual
and taking adequate safety precautions.
IMPORTANT: Record the pump model and serial numbers in the OPERATING DATA form below. You will save time and
expense by including this reference identification on any replacement part orders, or if you require service or application
assistance.
OPERATING DATA
It is to the user’s advantage to have the requested data filled in below and available in the event a problem should
develop in the blower or the system. This information is also helpful when ordering spare parts.
Model No. V-Belt Size Length
Serial No. Type of Lubrication:
Startup Date
Pump RPM Operating Vacuum
Pump Sheave Diameter Any other special accessories supplied or in use:
Motor Sheave Diameter
Motor RPM HP
NOTES:
(Recorded from nameplate on unit)

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KINNEY®KC™ SERIES MANUAL 1807-2
© 2010, Tuthill Corporation
DESCRIPTION
GENERAL
The KC series of compound high vacuum pumps covered by these instructions consist of two basic pump groups,
models:• KC-5 AND KC-8 • KC-15
The pumps within each of the first two groups are identical except for the motor and v-belt drive, which are changed to
give different rotational speeds. Specifically, the models KC-5 and KC-8 are the same except that the KC-8 is driven
faster.
Each Kinney KC pump is an air-cooled rotary piston high vacuum pump consisting of two rotary piston pumping stages,
which operate, in series. These pumps attain low ultimate pressures of less than 2 x 10-4 Torr (McLeod gauge). The
rugged, simple design ensures dependable service under the most severe applications without costly or complicated
maintenance. All components are easily serviced and no special tools are required. Reliable, leak-free shaft seals
require no adjustments or maintenance.
Each pump is equipped with a gas ballast valve, which regulates the vapor handling capacity of the pump. Gas ballast
aids in increasing the operation period between oil changes by preventing oil contamination by most condensable
vapors. It can also be used to clean the oil once it has become contaminated. Use of gas ballast will also reduce pump
operating noise.
A combination oil separator and oil mist eliminator is used in place of a conventional design oil separator. This unit
provides thorough filtering of the pump exhaust and results in a cleaner pump area, without expensive and space
consuming exhaust piping systems.
Pump specifications are shown in Figure 2 on page 6.
PUMP COMPONENTS
Each pump basically consists of two rotary piston pumping stages connected in series - a high vacuum stage and a
backing stage. The two rotary pistons are driven by two eccentric cams keyed to a common shaft. Each rotary piston
has a hollow extension (slide) that moves through a slide pin and leads to the inlet of the particular pumping stage.
Ports are cast into the inlet side of each piston and these ports together with the slide pins form automatic inlet valves.
The two pumping stages are connected in series by an internal duct and are enclosed in a single cylinder. The ends
of the cylinder are enclosed by an open head, through which the shaft extends, and a closed head. The open head
contains a shaft seal to prevent leakage along the shaft.
A spring loaded discharge valve is located at the discharge side of the backing stage (on the open head end of the
pump). An oil mist eliminator is mounted above the backing stage.
A sight gauge is provided for checking the oil level in the pump. When operating at low inlet pressure, the level should
be in the center of the sight gauge. Note that the oil level will change with large changes in pump inlet pressure.
OPERATING CYCLE
The operating cycle is shown in diagram form in Figure 1. Gas from the system enters through the pump inlet. It passes
through the hollow piston slide and out through the piston slide port into the space being created between the piston
and cylinder wall. As the piston rotates, this space increases and more gas is drawn in. At the same time, the gas taken
in and trapped on the previous revolution is on the compression side of the piston and slide where it is compressed and
discharged into the cored passageway that leads to the inlet of the backing stage.
The rotary piston pumping cycle is repeated in the backing stage. The gas is compressed and forced out through the
discharge valves along with a small amount of oil and then into the oil mist eliminator where the oil is separated from the
gas. The gas is discharged to atmosphere and the oil drains back to the reservoir.

6
SEALING & LUBRICATION
The cylinder walls, pistons, and
slide pins are lubricated and
sealed against the backflow of
gas by a film of oil which fills the
close running clearances. When
operating, the cylindrical part of the
piston almost touches the pump
cylinder at a line along the length
of the piston. At this moving line,
an effective wave of oil is pushed
ahead of the piston. The oil forms
a vacuum tight seal between the
piston and the cylinder, as well
as between all other working
components. The same oil also
supplies all required lubrication.
The oil flows through the pump
by means of differential pressure.
Because of high pressure at the
discharge and low pressure at the
inlet of each stage, the oil is forced
from both oil reservoirs (one at the discharge of each stage), through internal cored passageways leading to each
pumping stage. The oil from the backing stage reservoir lubricates and seals the backing stage, whereas the oil from
the high vacuum stage reservoir lubricates and seals the high vacuum stage. At the end of the compression stroke, the
oil is forced out with the discharged gas and returns to the respective oil reservoir.
OIL TYPES
The ability of each KC pump to obtain and hold pressures in the low micron range depends partly on the use of the
proper sealing and lubricating oil. The AX Vacuum Oil recommended for use with these pumps was originally developed
to obtain a dry, low vapor pressure fluid with suitable viscosity. Such oil is necessary for a high pumping speed at low
pressure.
Other fluids may have to be used for special applications. If varnishing is a problem, high detergent oils may be used.
Where low temperature starting is required, other more suitable fluid may be used. Tuthill Vacuum & Blower Systems
can recommend fluids to fit most special applications.
SPECIFICATIONS (FIGURE 2)
MODEL
FREE AIR
DISP.,
CFM
(L/sec)
PUMP
SPEED
(RPM)
MOTOR,
HP
(kW)
OIL
CAPACITY,
QTS.
(L)
INLET
CONN.
(FNPT)
DISCH.
CONN.
(FNPT)
PUMP
SHAFT
DIA., IN.
APPROX.
LENGTH,
IN.
(mm)
APPROX.
WIDTH,
IN.
(mm)
APPROX.
HEIGHT,
IN.
(mm)
APPROX.
WEIGHT
(COMPLETE
ASSEMBLY)
KC-5 5
(1.42) 630 .33 (0.25)
.5
(0.47) 1” 3/4” 3/4” 19.13 (486)
13.25
(337)
16.19
(411)
115 LBS
52 kg
KC-8 8
(3.78) 1000 .5 (0.37)
0.8
(0.76) 1” 3/4” 3/4” 19.50 (495)
12.31
(313)
16.19
(411)
120 LBS
54 kg
KC-15 15
(7.08) 525 1.0 (0.75)
3
(2.84) 2” 1-1/4” 3/4” 22.50 (572)
18.06
(459)
25.75
(654)
210 LBS
95 kg
Figure 1. Pump Operating Cycle

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INSTALLATION
MOUNTING
If only a bare shaft pump has been supplied, mount it on a level, rigid base. Connect it to a motor and operate it at the
rotational speed shown in the specification chart. Wire the motor so that the direction of the shaft rotation is as shown
by the arrow cast on the pump. On standard units, this is clockwise when facing the pump pulley.
V-BELT
When installing a V-belt drive, loosen the motor mounting screws and slide the motor towards the pump. Position the
v-belt on the pulleys. Move the motor away from the pump to tighten the drive.
Check the tension of the V-belt drive by applying normal thumb pressure to the top of the V-belt midway between the two
pulleys. Note that the tightest belt should not depress more than its own thickness. Adjust the belt tension as required,
but do not over-tighten or under-tighten the drive. A general rule for correct V-belt tension is to tighten the drive just
enough to prevent slippage when operating at full load, (that is, with the pump gas ballast valve fully opened). Recheck
the tension of the V-belts after the first 48 hours of operation.
DISCHARGE PIPING
If desired, connect discharge piping to the discharge
fitting on top of the oil mist eliminator to vent or reclaim
the exhaust gases.
When connecting the discharge piping, use a dropout
trap at the connection to the oil mist eliminator.
Otherwise, condensate from the discharge piping will
drip back into the oil separator and may contaminate
the oil.
A simple dropout trap consists of a tee equipped with
a drain cock for condensate removal. Place a flexible
connection, possibly rubber hose, at the discharge
of the pump to eliminate a rigid connection and to
provide a convenient disconnect point for servicing.
Turn down the outside end of the discharge line to
prevent entry of rain.
VACUUM PIPING
The vacuum piping to the pump inlet should be as
large and as short as possible. Use manifolding that
is no smaller than the pump inlet. It is recommended
that the inlet manifolding be arranged to prevent oil
migration back into the system. See Figure 3 for
recommended arrangements of vacuum manifolding
with integral oil baffles.
As with all rotary mechanical pumps, it is best to
install a flexible member in the suction manifold of the
pump to avoid alignment problems and to reduce the
possibility of transmitting vibration to and from other
components. Self-supporting bellows type flexible
connectors are recommended and are available from
Tuthill Vacuum & Blower Systems.
Figure 3. Vacuum Manifolding with Integral Oil Baffles

8
Other types may be too hard and transmit vibration, or too soft and may exert considerable force on the pump and piping
when collapsing under atmospheric pressure. Pour a small quantity of oil into the pump suction before connecting the
inlet piping to ensure proper lubrication at initial start-up.
Make all inlet connections vacuum tight. As a check, note that the pressure at the end of the connecting manifold should
be very close to that obtained with the pump inlet blanked-off. All demountable joints should be O-ring sealed.
If threaded connections are used, clean the threads and turn them together about two turns. Cover the remaining
exposed threads with a sealing compound such as Loctite 567 or PTFE Tape for piping up to 1” in diameter. Use Titeseal
(Radiator Specialty Company, North Carolina), on large pipe sizes. Screw the joint together tightly.
Install a vacuum isolation valve between the system and the pump with a means for connecting a vacuum gauge on
both sides of the valve and an air admittance valve on the pump side of the isolation valve. With such an arrangement,
it is possible to check either the system or the pump for leaks without disconnecting the vacuum piping. This isolation
valve will also allow the system to be kept under vacuum while the pump is not running, or the pump operating while the
system is open to atmospheric pressure.
VACUUM GAUGES
Two general types of vacuum gauges are used for the testing of vacuum equipment, total pressure reading types, such
as Thermistor or Thermocouple gauges, and partial pressure reading McLeod gauges. The McLeod gauge indicates the
partial pressure of permanent gases. It does not indicate the component of pressure due to condensable gases such
as water vapor. It is not greatly affected by vapor contamination unless the contamination pressure is quite high. It is
most useful in confirming pump performance and for determining the absence or presence of real leaks. Thermistor or
Thermocouple gauges are preferable for leak checking and indicating the degree of contamination.
A high Thermistor or Thermocouple gauge reading may indicate that the pump is contaminated, that it leaks, or both. A
high McLeod gauge reading means that a real leak is present.
ELECTRICAL CONNECTIONS
WARNING: Disconnect pump from electrical power source prior to making repairs or adjustments to any electric
component of the unit.
Check the operating voltage of the motor by comparing the lead connections with the markings on the motor. Connect
it to the proper power source through necessary switching and safety equipment. After wiring is complete, momentarily
start and stop the motor to check the direction of rotation against the arrow cast on the pump. If it rotates in the wrong
direction, switch any two wire leads to correct this problem. (These are generally printed on the connections cover
plate.) Note that standard pumps rotate clockwise when facing the pump pulley.
WARNINGS:
• When operating the pump in an enclosed area it is necessary, for health reasons, to have the area well ventilated.
If ventilation is not adequate, the pump discharge should be filtered or piped to open air.
• Do not block or restrict the flow of gas from the pump discharge. Back pressure could cause severe damage
• The belt guard must be properly secured to the pump at all times while the pump is running.
GENERAL
Kinney KC Model pumps are designed for low-pressure operation. They are generally not suitable for prolonged periods
of operation at high pressures. Each pump has been thoroughly tested and is ready for operation as soon as it is
installed and filled with oil. If the vacuum system is tight, including the connections to the pump, the ultimate system
pressure should be close to that obtained with the pump inlet closed off.
FILLING THE PUMP WITH OIL
Refer to the specifications chart for the quantity of oil required for the particular pump. On initial startup, pour a small
quantity of oil into the pump inlet to insure adequate lubrication on starting. Pour the remainder of the required oil
quantity into the pump as follows:
KC5/8: Unscrew the oil mist eliminator from the pump. Remove the high vacuum stage oil fill plug. Pour approximately

9
one-third of the required quantity of oil into the high vacuum stage of the pump. Pour the remaining quantity of oil through
the threaded hole from which the oil mist eliminator was removed. Check that the fill plug and gasket are clean and in
good condition. Replace the plug and gasket, making a vacuum tight seal. Replace the oil mist eliminator on the pump.
KC 15: Pour approximately 1/8 of a quart of oil into the pump suction port. Pour remaining 7/8 of a quart into the high
vacuum stage oil fill port. Continue to pour the remaining oil into the discharge port of the pump until the oil level is
approximately 1/8” below the top of the sight glass.
PRE-START CHECKS
1. Check that the suction lines are tight and absolutely free of all foreign matter.
2. Check that the pump has been filled with oil.
3. Check that the pump can be turned over by hand without mechanical interference. Note that the inlet should be
open to atmospheric pressure and that additional turning force is required when the pump discharges.
4. Check the v-belt tension by applying normal thumb pressure to the top of the tightest belt about midway between the
two pulleys. The tightest belt should depress about its own thickness indicating proper tension. In general, v-belts
should be tightened just enough to prevent slippage when operating the pump under load (that is, operating with a
fully open gas ballast valve).
5. Check that all wiring is completed and correct. Momentarily, start and stop the pump to check the direction of pump
shaft rotation. On standard pumps, it should be clockwise facing the pump pulley.
OPERATION
STARTING THE PUMP
1. Perform the pre-start checks as indicated previously. Note that the minimum starting temperature is 50°F.
2. Depress the motor start switch to start the pump. It is recommended that the pump be warmed up before starting
process work. This requires operation for about 10 minutes with the pump isolated from the process equipment.
3. Open the pump isolation valve, if one is provided, allowing the pump to evacuate the process equipment.
4. To reduce the operating sound of the pump, slightly open the gas ballast valve. This is a preferred method of
operation since it helps to keep the oil clean.
5. Note that the oil level should change when operating the pump at high and low inlet pressures. This indicates proper
oil flow through the pump. When the pump is first started, the oil level will rise in the backing stage. When the inlet
pressure is reduced to the micron (10-3 Torr) range, the oil level will drop to about the center of the sight glass.
If the pump is used in an application where excessive amounts of water vapor are encountered, remove the mist
eliminator element to prevent condensation. Periodically stop the pump and open the backing stage oil drain to drain
out water accumulation. Drain out all water accumulation each time before starting the pump, because if the water level
rises above the oil inlet port, the pump may be damaged on start up.
STOPPING THE PUMP
1. If a vacuum valve is provided between the pump and the process equipment, place this valve in the closed position.
2. Vent the pump suction to atmospheric pressure by opening a vent valve. Turn off the power to the pump motor.
Note that if the system does not have a pump isolation valve, vent the system to atmospheric pressure to prevent
oil from being drawn into the vacuum system. Oil flooding of the pump cylinder could make restarting difficult. Note
that a solenoid operated air inlet vent valve is offered as an accessory on the Model KC-15 pump. This valve is
wired across the motor so that it will automatically open to vent the pump inlet when the pump power is turned off.
Note that this valve is adequate for venting only a small volume. It is not large enough to vent an attached system.

10
GAS BALLAST
Gas ballast is an operating mechanism, which is used to prevent the condensation of vapor in a vacuum pump. Vapor
present in the gas being pumped can condense during the vacuum pump compression cycle and mix with the vacuum
pump oil. Since this oil is recirculated through the pump, the condensate is carried with the oil and allowed to re-
evaporate, causing poor pump performance and making frequent oil changes necessary. By using gas ballast, most
vapors can be passed through a vacuum pump without condensing and then discharged with the pump exhaust.
In addition to preventing vapor condensation, the use of gas ballast also reduces discharge valve noise to a low level. It
is generally possible to eliminate valve noise with a small gas ballast flow, which does not seriously increase the ultimate
pressure. If the ultimate pressure is tolerable, this is a preferred method of operating since it also helps to keep the oil
clean.
The setting of the gas ballast valve is best determined by trial and error because the amount of condensable vapor, as
well as the system operating conditions, vary with different processes. In addition, the motor power consumption and
the ultimate pressure increase in proportion to the gas ballast airflow.
To use the gas ballast technique, proceed as follows:
1. Continuous gas ballast: With the pump operating, open the gas ballast valve until the ultimate pressure is
slightly below that needed for the process. Operate the pump in this manner continuously to aid in preventing oil
contamination.
2. Intermittent gas ballast: With the pump operating, fully open the gas ballast valve during periods when this will not
affect the process (work preparation, recycling, etc.). This will aid in cleaning up oil contamination. If not convenient,
operate the pump in this manner overnight to clean up badly contaminated oil.
If it is necessary to clean up the oil in the shortest period, the length of time needed can be estimated as follows:
Observe the pump’s blank-off pressure with the gas ballast valve fully closed. Open the gas ballast valve fully and
operate the pump for a short period (15 to 20 minutes). Close the gas ballast valve fully and observe the pressure
change in that time period.
Use this as a rough
guide to estimate the
total time required
to obtain the desired
blank-off pressure. The
oil is clean when there
is no further reduction in
pressure.
SPECIAL
REFRIGERATION
SERVICE UNITS
Kinney offers high
vacuum pumps
that are specifically
engineered for servicing
refrigeration equipment,
which includes
thorough vacuum
drying, degassing, and
fast leak detection.
When connecting a
pump to a refrigeration
unit, use 1/2”, 5/8”, or
3/4” copper tubing.
Smaller tubing is not Figure 4. Identification of Pump Components

11
recommended because of the restriction to gas flow. If it is necessary to vent the pump exhaust outside, use ordinary
hose of suitable diameter. Do not position the hose so that condensate can collect and cause blockage, such as in a
loop or sag in the hose.
Before and after using a pump on refrigeration equipment, remove the cap in the drop-out trap to drain all liquid
condensate. Drain the pump, flush, and recharge it with fresh oil each time after using it, if the pump will not be used
again for two or three days. This will protect the pump during storage from rust and contaminants, which are frequently
encountered in this type of pump service.
MAINTENANCE
PUMP PERIODIC MAINTENANCE
Check the oil level daily for the first week of operation and weekly thereafter. The oil level should be about midway
on the sight gauge when operating at low inlet pressures. However, the oil level will change with large changes in
pump inlet pressure. If there are no changes in the oil level, check for obstructed oil passages. Check the condition of
the oil periodically by draining a small quantity of oil into a clean container and visually inspecting it for solid or liquid
contaminants. Change the oil when contaminated. There is no fixed interval for changing the pump oil, since applications
vary widely. This can be determined only by experience or deterioration of pump performance. As a minimum, the pump
oil should be changed after each three-month operating (not storage or idle) period.
CHANGING THE OIL
All moisture as well as other vapors present in the system will be drawn into the pump. Some may be condensed and
will collect in the backing stage oil reservoir; contaminating the pump oil and causing poor pump performance. Proper
use of gas ballast will minimize the amount of condensate and reduce the frequency of oil changes.
Change the oil when it becomes contaminated with foreign matter or with chemicals. The period between changes can
be best determined by the user for his particular operation.
1. To drain the oil, remove both drain plugs on the side of the cylinder.
2. If drain valves are provided, open both drain valves.
3. To clear all of the oil out of the cylinder, open the pump inlet (suction) to atmosphere. Turn the pump over a few
revolutions to drive the oil out of the cylinder.
4. Replace the drain plugs.
5. Fill the pump with oil as directed under the OPERATION section per Filling The Pump With Oil.
NOTE: If the oil is badly contaminated, it may be necessary to flush the pump by changing the oil several times, with a
short period of operation between each change to check the pump’s blank-off pressure.
FLOODING
If the pump is not vented to atmosphere when stopped under vacuum, it is possible for oil to flood the pump cylinder
causing a hydraulic lock. When this occurs, difficulty may be experienced in starting the pump. To release this lock, fully
open the gas ballast valve and try to turn or rock the pump pulley by hand to force out the oil. Do not apply excessive
force to turn the pump pulley (such as with a long pry bar).
OIL MIST ELIMINATOR
It may be necessary to clean out the oil separator or change the replaceable filter element after the pump has been in
service for a long period, or quite frequently if mechanical contaminants are present, or if oil sludging due to chemical
attack takes place. To do this, remove the top cover of the oil separator and clean it as required.
Since pump applications vary greatly, operating experience is the best guide when determining the interval for replacing
the oil mist eliminator element. NOTE: Drain valves in the OME are application-specific.

12
Change the oil mist eliminator if:
1. Visual inspection shows the oil mist
eliminator element to be blocked by
foreign matter.
2. Pump back pressure as read at
inlet to the oil mist eliminator (or
the oil fill plug) reads over 4 to 6
PSIG (275 to 400 mbar g). This
indicates element is contaminated.
3. Motor current exceeds
manufacturer’s recommendations
shown on motor nameplate. This
indicates element is contaminated.
4. Mist discharged from the oil mist
eliminator. This indicates element
is ruptured or gasket is not sealing.
Flooding of the oil separator-mist
eliminator assembly can happen if
the pump is operated for prolonged
periods above 5 Torr (6.7 mbar a). This
oil buildup will cause oil droplets to be
discharged when the pump is operating.
To remove this trapped oil, lower the
pump operating pressure below 5 Torr
(6.7 mbar a) until the trapped oil can
return to the pump.
If it is not feasible to operate the pump
at 5 Torr (6.7 mbar a) or below to
prevent flooding the oil separator-mist
eliminator assembly, then an oil return
line should be installed, see Figure 5
below. If the pump operating range is
5 to 150 Torr (6.7 to 200 mbar a), the
return line should connect to the gas
ballast valve in which case the valve
must not be closed. If the operating
range is above 150 Torr (200 mbar a)
the oil return line should connect to the
pump at the suction port area.
STALLING
If the pump stalls at any time it may
be due to loose belt, lack of lubrication
or foreign matter in the pump. If the
pump cannot be turned over by hand
after cooling down, the pump must be
cleaned. Cleaning and inspection of
the pump is covered in the disassembly
section.
Figure 5. Oil Return Line
Figure 6. Breakdown of
Common Faults in Vacuum Systems
* Pressure rises due to internal causes such as contamination
by high vapor pressure materials outgassing from associated
equipment work, and leaking from trapped volumes of air.
System not
Operating
Pressure not
Attainable
Associated
Process
Equipment
Vacuum
Pump
Virtual Leaks*
Leaks
Operator Error
Contamination
Leaks
Malfunctions

13
TROUBLESHOOTING
Although KINNEY®KC™ rotary piston vacuum pumps are well-designed and manufactured, problems may occur due to
normal wear and the need for readjustment. The chart below lists symptoms that may occur along with probable causes
and remedies.
SYMPTOM PROBABLE CAUSE REMEDY
System ultimate pressure
excessively high
Process equipment faulty.
Vacuum pump improperly operating
or malfunctioning
Check pump performance. See “Checking Pump Performance”.
Process equipment contaminated by high vapor
pressure material.
Clean equipment with acetone, alcohol, or either.
Pump down with vacuum pump overnight.
Process equipment leaks. Leak check process equipment. See “ Process Equipment Leaks”.
Improper vacuum pump oil flow. Clean oil ducts.
Vacuum pump oil contaminated. Change pump oil, see “Changing the Oil” & “Oil Contamination”
Discharge valves malfunctioning. Check valves per “Discharge Valves”.
Vacuum pump leaks. Leak check pump per “Pump Leaks”.
Vacuum pump shaft seal malfunctioning Check shaft seal per “Shaft Seal”.
Vacuum pump internal parts worn or damaged. Disassemble pump and inspect internal part. See “Disassembly”.
Excessive pump noise
at low pressures. Hydraulic noise of pump discharge. Open gas ballast valve.
Pump stalls.
Electrical power loss. Check power at pump.
Pump malfunctioning. Pump oil contaminated or
pump is insufficiently lubricated.
See “Stalling”. Refer to maintenance paragraphs on “V-Belt Drive” and “
“Changing the Oil”.
Pump discharge line blocked. Clear pump discharge line. Check oil mist eliminator element for blockage.
Pump will not start.
Electrical failure. Check for power at pump. Check motor start controls and motor.
Pump flooded with oil. Clear oil from pump by turning over by hand or disassembling the pump. See
“Flooding”.
Temperature excessively low. Heat pump to minimum starting temperature of 50° F (10° C).
Oil discharged from oil mist
eliminator. Excess oil on discharge side of oil mist eliminator.
Unscrew oil mist eliminator and pour oil through the discharge fitting back into
the pump.
As an alternative, on KC-5, KC-8 and KC-15 pump reduce pump inlet pressure
below 10 Torr to allow collected oil to drain back through the integral check
valve in the oil mist eliminator.
CHECKING PUMP PERFORMANCE
If the processing time increases or the ultimate
pressure becomes poor with no recent changes in
the process or in the system configuration, test the
pump to determine if the trouble is in the pump or the
connected process equipment. To check the condition
of the pump, measure the blank-off pressure ads
directed below using a McLeod gauge.
If possible, also read the blank-off pressure with a
thermistor or thermocouple gauge. Refer to Figure 7
and the Troubleshooting chart above for a listing of
common faults in vacuum systems. Figure 7. Pump Test Manifolding

14
To read the pump blank-off pressure:
1. Close off the pump inlet by means of a vacuum valve or short segment of manifolding as shown in Figure 7.
2. Connect a vacuum gauge to the pump side of the valve or manifolding. Position the gauge connection so that it will
not become flooded or blocked by splashing pump oil.
3. Operate the pump for a short period, about 15 minutes, until the lowest pressure is reached. Note the reading
obtained.
The reading obtained should be between the pump’s specification blank-off pressure (low end) and the pressure needed
for the process (high end). Average blank-off readings are 0.5 to 2.0 microns with a McLeod gauge reading.
Note that for practical consideration, pumps need not obtain pressures lower than 90% of the required operating
pressure to be usable. If the McLeod gauge reading is low and the Thermocouple gauge reading is high, the pump oil is
contaminated. Change the oil and re-check the pump blank-off pressure. (In some instances it is necessary to change
the oil several times to flush all traces of contamination from the pump.) Note that if a Thermocouple gauge is not
available and the pump oil has been in service for an appreciable period, it is best to change the pump oil several times
to eliminate pump oil contamination as a possible cause of poor pump performance. After changing the oil, re-check the
blank-off pressure.
If both the McLeod and Thermocouple gauge readings are high, indication that the oil is not contaminated, the pump is
leaking. Proceed as directed in “Pump Leaks”.
PUMP LEAKS
If the pump is suspected of leaking (after eliminating oil contamination as the cause of poor performance), use a
plastic sealing compound, such as Apiezon Q, to seal over suspected areas, and check pump blank-off performance
before making permanent repairs with Loctite 515. If gasketed connections are suspected, remake the connections with
temporary gaskets of plastic sealing compound; these should not be made too thick since the material may be squeezed
into the equipment.
Check carefully around the head-to-cylinder joints, securing bolts, plugs, shaft seal housing joints, and generally any
penetration into the vacuum pumping portion of the pump. Check the shaft seal for mechanical defects, such as a
cracked carbon washer or hardened rubber components.
CHECKING PROCESS EQUIPMENT
If the blank-off test shows that the vacuum pump is functioning properly but that the process equipment is faulty, the
trouble can be isolated further by applying the following procedures:
1. Pump down each segment of the process equipment individually, starting at the segment closest to the vacuum
pump.
2. Check the lowest pressure attainable when each segment is added. If the pressure is close to that obtained
previously, add the next segment. If the pressure is not, leak test the last segment. When leak checking process
chambers, start at the air and gas inlet valves, doors, sight ports, electrical and mechanical feedthroughs, gauge
tube fittings, and any other penetrations, especially threaded, gasketed and o-ring connections. After a suspected
leak has been found, cover it with plastic sealing compound, such as Apiezon® Q, and check the equipment
performance before sealing the leak permanently. Thus, all permanent repairs can be made at the same time.
PROCESS EQUIPMENT LEAKS
Attach a vacuum gauge to the connection on the system side of the vacuum valve. For this test, clear the system of
any process work, which might give off vapors and change the reading. Run the pump to obtain the lowest possible
pressure and close the valve. Observe the pressure rise. If the pressure rise is greater than desired, or if the ultimate
pressure is too high, check and eliminate all leaks. Check the system carefully for loose joints and obvious leaks. Use a
leak detector if available. If a leak detector is not available, proceed as directed in “Leak Checking Techniques” below.

15
LEAK CHECKING TECHNIQUES
If a leak detector is not available, use the following methods to locate leaks:
1. Cover suspected leaks with a low vapor pressure sealing compound such as Apiezon Q, Duct Seal or Plasticine®.
2. Do this while pumping on the equipment and monitoring the pressure. A sudden decrease in pressure indicates that
a leak has been covered. Repair leaks permanently as necessary.
3. If the leak is large, causing pressures in the Torr range, pressurize the process equipment with one PSIG of clean
compressed air and paint a soap solution on suspected leak areas. Bubbles indicate leaks. De-energize and isolate
the pump during the leak checking. Repair leaks as required.
4. If the leak is small, causing pressures in the sub Torr range, use a fast acting thermocouple or thermistor gauge
in conjunction with a probing medium such as helium. Position the vacuum gauge head downstream from the
suspected leak area, between the leak and the pump. When the pressure has been reduced so that the gauge may
be used, apply probing medium to suspected leak areas. If the probing fluid is directed at the leak or an area close
to it, a sudden change in pressure will occur. Cover suspected leaks with plastic sealing compound and continue
leak checking until the desired pressure is obtained.
If leak checking fails, disassemble and remake all demountable joints and connections using new gaskets or vacuum
sealing compound such as Loctite 515. Temporary gaskets may be fabricated from plastic sealing compound but these
should not be made too thick since the material may be squeezed into the equipment.
OIL CONTAMINATION
When the pressure has been satisfactory for some time and then gradually increases, this indicates oil contamination.
Clean up the oil by applying gas ballast, or change the oil as directed in “Changing The Oil”. A change in the color of
the oil does not necessarily mean that it is not satisfactory for use. On the other hand, vapors may contaminate it and
not show any color change.
DISCHARGE VALVE
If the cause of poor pump performance was not due to leaks or oil contamination, the next step is to inspect the
discharge valve. The discharge valve is located at the exhaust port of the backing stage. It should not cause trouble
unless mechanically damaged or prevented from sealing properly due to foreign matter on the valve seat. When the
pump is operating without gas ballast, a sharp valve noise (click) indicates proper valve closing.
To inspect the discharge valve, proceed as follows:
1. Drain the pump oil by removing both drain plugs (or by opening the drain valves if provided). Remove the cylinder
cover to expose the discharge valve.
2. Remove both guide rods, discharge valve springs,
discharge valve block, and discharge valve. Note
how the components were removed so they can be
replaced correctly.
3. Check the discharge valve; it should be flat and not
worn thin on the edges or kinked. The valve will
normally show the outline of the cylinder discharge
holes. Clean this from the valve and check that the
holes are not worn into the valves.
4. Check the discharge valve block; it should not be
worn out of round in the holes or damaged around
the lower edge. Check for flatness with a straight
edge.
5. Check the springs; they should show no signs of
weakening such as unevenness or bulging of coils. Figure 8. Typical Discharge Valve Assembly

16
6. Check the guide rods; these should be smooth and not worn in ridges, damaged, or worn in any way that would
allow the block to bind as it slides up and down. Check the valve seat in the cylinder; it should be smooth and flush
with surrounding area.
7. Replace worn components as required.
8. Replace the discharge valve, valve block, springs, and the guide rods in the same order and position as removed.
Replace the cylinder cover and secure it in place. Replace the oil drain plugs (or close the drain valves) and fill the
pump with oil as directed “Under Filling The Pump With Oil”. Test the pump per “Checking Pump Performance”.
SHAFT SEAL
Under normal conditions, the shaft seal has a long, trouble free life. It may become worn or scratched on the sealing
faces by contaminated oil or it may be damaged by inadequate lubrication.
To inspect the shaft seal, proceed as follows:
1. Position the pump so that it rests on the closed head to prevent oil from draining out of the shaft seal housing.
2. Remove the belt guard and belts. Remove the pump pulley and drive key from the pump shaft.
3. Remove the shaft seal retaining ring from the shaft.
4. Remove the rotating portion of the shaft seal from the shaft; this may require a heavy pull, especially if the unit has
heat bonded to the shaft. In extreme cases, it may be necessary to remove the open head (or shaft seal housing)
to remove the seal.
5. If necessary, remove the seal seat from the pump.
6. Check the mating seal faces on the stationary and rotating segments of the seal assembly; there should be no
scratches or indentations. The faces should be smooth and shining.
7. Check the rubber friction ring. It should have no scratches or grooves on the inside diameter that seals to the shaft.
It should be flexible - not hardened.
8. Check the seal seat gasket. It should not be cut, nicked, or hardened. Cracks or hardening of rubber components
indicate exposure to excessive temperatures, and the seal should be replaced.
9. If the components are defective or damaged, replace the entire seal assembly.
10. Coat the seat gasket and seal seat with AX vacuum oil and insert in position on the open head and shaft seal
housing. Use caution so that the gasket does not roll or twist, since creases or cuts cause a vacuum leak.
11. Coat the rotating portion of the shaft seal with AX vacuum oil. Cover the keyway on the shaft with a plastic tape or
by forming a thin piece of metal over the shaft. Coat the
shaft and metal cover with oil.
12. Carefully push the rotating portion of the shaft seal
(consisting of the seal face retainer shell, friction ring,
spring, and spring holder) over the shaft by means of a
pipe sleeve or a large washer against the outer spring
holder. Note that the friction ring fits tightly on the shaft to
prevent slippage of the rotating portion of the shaft seal.
Be careful not to damage the seal faces or cut the rubber.
Check that the seal face is not tilted. Remove the cover
from the shaft and install the retaining ring.
13. Replace the pump drive key and pulley. Replace the v-belt
drive and tension it as indicated under “Mounting” section
of the INSTALLATION instructions. Replace the belt guard.
Test the pump per “Checking Pump Performance”.
Figure 9. Shaft Seal Assembly

17
DISASSEMBLY
These instructions are for complete disassembly. However, the pump should be disassembled only to the extent
necessary to repair it. Reference is made to the open head and closed head ends of the cylinder. The open head is the
end through which the shaft extends.
1. Drain the oil as directed in “Changing The Oil”. Remove the belt guard (if supplied) and the belts.
2. Disconnect the piping to the pump suction.
3. Remove the pump pulley and drive key.
4. Remove the pump assembly from the base and position it on a work bench.
5. If pump is so equipped, unscrew the oil mist eliminator.
6. Remove the discharge valve assembly as follows: (a) Remove the cylinder cover and gasket. (b) Remove
both guide rods, both discharge valve springs, the discharge valve block, and the discharge valve. Note how the
components were removed so that they can be replaced correctly.
7. Remove the shaft seal as follows: (a) Remove the shaft seal retaining ring from the shaft. (b) Remove the rotating
portion of the shaft seal from the shaft; this may require a heavy pull, especially if the unit has heat bonded to the
shaft. In extreme cases, it may be necessary to remove the open head or shaft seal housing to remove the seal. (c)
Remove the stationary portion of the shaft seal, (seal seat), from the pump.
8. Remove the shaft seal housing by removing the securing cap screws and break the seal between the shaft seal
housing and the head. Remove the shaft seal housing o-ring.
9. Remove the gas ballast valve and connecting fittings.
10. Remove the open head as follows: Remove the open head cap screws and break the seal between the head and
the cylinder. If necessary, remove the open head bearing by pressing it out of the head.
11. Remove the open head piston and slide pin. Mark the piston and the slide pin so that they can be reassembled in
the same position. Although parts are interchangeable between the high vacuum stage and the backing stage, it is
advisable to replace piston and slide pin in the same stage once the parts are worn in.
12. Remove the cap screws securing the closed head cap to the closed head.
13. Remove the cap and sealing o-ring.
14. Remove the closed head by unscrewing the closed head securing cap screws and break the seal between the
closed head and the cylinder.
15. Remove the closed head piston and slide pin. Note how they were removed so that they may be reassembled in
the same position.
16. Remove the closed head bearing if necessary, by pressing it out of the closed head. Do not mar the finished faces
of the head.
17. Remove the shaft and cams as follows: (a) Remove the closed head cam, if necessary, by tapping the shaft
through the cam using a lead mallet or hammer and wooden block. (b) Remove the shaft with the open head cam
attached. Do not remove the open head cam unless replacement of the shaft or cam is necessary. If cam removal
is necessary, press the cam from the shaft.
18. Tap out the center wall seal with a wooden block and hammer if seal removal is necessary.
19. Remove additional parts such as elbows and drain plugs and sight glass as required to complete the pump
disassembly
20. Inspect all parts for wear and damage and replace components as required.

18
REASSEMBLY
Before starting to reassemble the pump, inspect all parts to make sure that they are clean, smooth, and free of nicks
and old sealing compound. Replace all worn or damaged parts. Do not use solvents such as kerosene or carbon
tetrachloride for cleaning unless facilities are available to evaporate them by vapor degreasing or washing in acetone
or alcohol. Tuthill Vacuum & Blower Systems recommends a general cleaning solvent with flash point exceeding 140° F
(60° C), such as solvent-140. Avoid leaving the excessive solvent on the pump parts. As the pump is reassembled, coat
the cylinder and internal moving parts lightly with AX Vacuum Oil to facilitate assembly and to ensure that all parts are
lubricated when the pump is first started.
1. If removed, replace the cam key and press the open head cam onto the shaft. Use a securing compound, such as
Loctite®, if necessary. Insert the cam key and top the closed head cam onto the shaft. Rotate the shaft to check that
the cams do not bind on the center wall.
2. On the KC-5 and KC-8, position the piston so that the inlet ports in the piston slide are facing away from the
discharge valve side of the pump. Place the closed head slide pin on the piston with the flat side down
and the closed end of the slide pin toward the center wall. Insert the piston and slide pin into the pump.
On the KC-15, position the closed head piston with the inlet slots in the piston slide facing away from the discharge
valve side of the pump. Place the closed head slide pin over the piston slide with the scalloped edges up and the
arrow cast into the slide pin pointing toward the discharge valve side of the pump. Insert the piston and slide pin
into the pump.
3. Check that the sealing faces of the closed head and cylinder are clean and free of all sealant. Carefully apply a
thin coat of Loctite 515 to the sealing faces of the cylinder and the head. CAUTION: If too much or too thick an
application of sealing compound is used, it will squeeze into the pump during assembly and will cause the working
parts to stick or clog the small oil ducts.
4. Position the closed head on the cylinder and install the securing cap screws. Tighten the closed head cap screws.
Rotate the shaft to check that there is no binding. Replace bearings into head.
5. Check that the sealing faces of the closed head and closed head cap are clean. Place the sealing o-ring on the
closed head cap. Position the cap on the closed head; install and tighten the securing cap screws.
6. On the KC-5 and KC-8, position the open head piston with the inlet port in the piston slide facing away from the
discharge side of the pump. Position the slide pin on the piston slide with the flat side down and the closed end
toward the center wall. On the KC-15, position the open head slide pin with the inlet ports in the piston slide facing
away from the discharge side of the pump. Position the open head slide pin with scalloped edge up and the arrow
cast into the slide pin pointing towards the discharge side of the pump.
7. Install the open head piston and slide pin in the pump.
8. Check that the open head end of the cylinder and the cylinder mating surface are both free of all sealing compound.
Apply a thin coat of Loctite 515 sealing compound to the sealing faces of the cylinder and head. Position the open
head on the cylinder and tighten the securing cap screws. Tighten the open head securing cap screws. Rotate the
shaft to check that there is no binding. If it binds, a few gentle taps on either end of the shaft will usually free it. If
not, remove the heads, one at a time, and correct the trouble. Replace bearings into head.
9. Install the shaft seal housing and shaft seal housing o-ring on the open head. No sealing compound is required.
Tighten the securing cap screws.
10. Refer to Figure 9 on page 16 and assemble the shaft seal assembly as follows: (a) Apply a light coat of AX vacuum
oil to the seat of the shaft seal assembly. Place the seat gasket on the seat and carefully slide the seat and gasket
over the shaft into position on the pump. Press in both pieces until they are seated uniformly against the shoulder.
Do not damage the gasket or mar the face of the seat. (b) Coat the rotating portion of the shaft seal (face, shell,
bank, and friction ring) with AX Vacuum Oil. Cover the retaining ring groove and the keyway on the shaft with plastic
tape or by forming a thin piece of metal over the shaft. Coat the shaft and the metal cover with oil. Carefully push
the rotating portion of the shaft seal over the shaft by means of a pipe sleeve or a large washer. Be careful not to
damage the seal face or cut the rubber. Remove the cover from the shaft. (c) Place the spring and the spring holder
on the shaft and compress the spring beyond the retaining ring over the shaft until it snaps into its groove. Assemble
the discharge valve, valve block; two valve springs, and the two valve guide rods on the cylinder, replacing them in
the same position as they were removed.

19
11. Assemble the discharge valve, valve block, two valve springs, and the two guide rods on the cylinder, replacing
them in the same position as they were removed.
12. Replace the cylinder cover and gasket and tighten the securing cap screws.
13. Replace the gas ballast assembly on the pump, tightening it securely.
14. Replace the oil mist eliminator on top of the pump.
15. Replace any plugs or fittings that were removed.
16. Replace the pump assembly on the base and install the drive key and pump pulley.
17. Replace the v-belt on the pulleys. “See V-Belt Drive” of INSTALLATION section for additional
information if desired). Tighten the drive by moving the motor until the tightest belt will depress no more than its
own thickness under normal thumb pressure. Replace the belt guard and secure it in position.
18. Check that the pump oil drain plugs or valves are in place and fill the pump with oil as directed under “Filling The
Pump With Oil”. Test the pump per “Checking Pump Performance”.
19. Reconnect the vacuum piping from the process equipment to the pump suction (inlet)
REPLACEMENT PARTS
GENERAL
The drawings and parts lists cover all of the parts in each pump. Any of these parts may be ordered from the factory for
replacement as necessary. Always include the pump model and serial numbers.
SPARE PARTS
Recommended spare parts are indicated on the parts lists by an asterisk preceding the description of the item. This
includes all gaskets, O-rings, shaft seal, and discharge valve. It is recommended that these items be maintained in
stock for use as necessary. It is also recommended that sufficient AX Vacuum Pump Oil be kept on hand for at least one
change and also a can of Loctite 515 for sealing leaks. It is also recommended that an accurate vacuum gauge, such
as the Kinney McLeod gauge Model TD, be obtained for checking pump performance.
ORDERING PARTS
When ordering parts, order them by item number and description, and specify the model and serial number stamped
on the nameplate so that the pump may positively identified. In some instances, newer parts may be substituted for
previous ones if the particular pump can be identified.
NOTES:

20
NOTES: