Tuthill KINNEY KDH-65 User manual

KINNEY®
SINGLE-STAGE
ROTARY PISTON
VACUUM PUMPS
Models:
KDH-65
KDH-80
KDH-130
KDH-150
Instruction Manual
1817
-
1
Revision 2001
FOR SALES AND SERVICE PLEASE CALL:
PTB SALES T:: 626.334.0500
[email protected]
[e-mail]
www.ptbsales.com
DATE SERVICED:
VIEW OUR INVENTORY

1
Safety Instructions for Rotary Piston Pumps
Please read the following safety information on this page before
operating your Vacuum Pump.
•Do not operate the pump unless the beltguard is properly attached. The power supply must be dis-
connected before removing or installing the belt guard. Operating the pump without the beltguard
properly secured in place exposes people in the vicinity of the pump to risk of injury from rotating
drive parts.
•Do not operate the pump with oxygen enriched gas in the suction line, where the proportion of
oxygen exceeds 20%, unless the pump has been prepared with an inert fluid suitable for the appli-
cation.
Pumping oxygen enriched gases with mineral oil or other non-inert fluids can cause an explosion
in the pump, resulting in damage to the pump or injury to personnel.
•Take the following precautions to avoid prolonged or excessive exposure to oil mist or process
materials from the discharge of the pump.
Do not allow the pump to discharge into a closed room, or a room without adequate ventilation.
Always use a discharge oil mist eliminator unless the pump discharge is vented to the open air.
Piping the outlet of the oil mist eliminator to the outside air is highly recommended.
•Never restrict the pump discharge line in any way, or place any valves in the discharge line.
The vacuum pump is a compressor and will generate high pressures without the motor stalling
when operated at low suction pressures. Excessive pressure build up could cause damage to the
pump or injury to personnel.
•Disconnect the pump from the electrical supply at the main disconnect before dismantling or serv-
icing the pump.
Make sure the pump is completely reassembled, the beltguard is replaced, and all drain and fill
valves and plugs are closed before reconnecting the power supply.
•Accidental starting or operation of the pump while maintenance is in progress may cause damage
to the pump or injury to personnel.
•Lift the pump only with the lifting eyebolts supplied. Make sure any other equipment attached to
the pump is removed before lifting the pump.
•Do not touch hot surfaces on the pump. In normal operation at low pressures surface temperatures
will not normally exceed 180°F. Prolonged operation at 200 Torr may cause surface temperatures
up to 220°F.

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TABLE OF CONTENTS
INTRODUCTION..................................................................................................................... 3
DESCRIPTION ......................................................................................................................... 3
Operating Mechanism............................................................................................................. 3
Inlet and Outlet Valves ........................................................................................................... 4
Sealing and Lubrication.......................................................................................................... 4
Sealing Oils............................................................................................................................... 4
Operating Cycle....................................................................................................................... 4
Gas Ballast................................................................................................................................ 5
INSTALLATION ...................................................................................................................... 6
Mounting the Pump................................................................................................................. 6
Connecting the Cooling Water............................................................................................... 6
Vacuum Piping ........................................................................................................................ 6
Oil Separator Piping ............................................................................................................... 6
Electrical Connections ............................................................................................................ 8
Prestart Checks........................................................................................................................ 8
OPERATION............................................................................................................................. 8
Starting the Pump ................................................................................................................... 8
Stopping the Pump .................................................................................................................. 9
Changing the Oil..................................................................................................................... 9
Gas Ballast................................................................................................................................ 9
Oil Separator........................................................................................................................... 10
SOLENOID VALVES............................................................................................................. 10
General ................................................................................................................................... 10
Electrical Connections .......................................................................................................... 10
Overheating of Coils.............................................................................................................. 10
Sticking and Jamming........................................................................................................... 10
Wet Coils ................................................................................................................................ 11
Coil Replacement................................................................................................................... 11
Noise........................................................................................................................................ 11
TROUBLESHOOTING.......................................................................................................... 11
General ................................................................................................................................... 11
Isolating Troubles.................................................................................................................. 11
Checking Process Equipment............................................................................................... 12
Leak Checking Techniques .................................................................................................. 12
Pump Test .............................................................................................................................. 13
Pump Leaks............................................................................................................................ 13
Solenoid Valve ....................................................................................................................... 14
Discharge Valaves.................................................................................................................. 14
Mechanical Shaft Seal........................................................................................................... 15
Stalling.................................................................................................................................... 16
MAINTENANCE .................................................................................................................... 16
OVERHAUL............................................................................................................................ 17
KDH-130B......................................................................................................................... 17-18
KDH-65 and 130 ............................................................................................................... 19-20
REPLACEMENT PARTS...................................................................................................... 21
PARTS LISTS & PUMP VIEWS .....................................................................................22-25

3
INTRODUCTION
This manual applies to KDH-65, KDH-80, KDH-130, and KDH-150 pumps built from 1974 to
date. Earlier models may differ.
The KDH-130 was replaced by the KDH-130B (and by the KDH-131 for radiator filling appli-
cations) in November 1987. Serial numbers between 871080 and on are the new “B” model.
The differences between the KDH-130 and the KDH-130B are:
•The cylinder casting design is changed, and new water jacket plates are fitted to the KDH-
130B.
•The KDH-130B is five inches shorter than the previous model due to a more compact shaft
support structure.
•
Replacing KDH-130 with KDH-130B
If there is no fixed vacuum manifold and the suction flange position can be changed, use the
bolt down holes provided in the bottom plate which line up with the bolt holes in the existing
base. The whole pump will move 2-7/8 inches toward the drive.
If the vacuum manifold is fixed and the base cannot be moved, bolt the pump down in line with
the manifolding. The belt guard and motor base must be moved 2-7/8 inches toward the center
of the base as follows.
Modify the belt guard mounting brackets by bending them or cutting off and welding short an-
gle iron brackets with bolt holes. New matching bolt holes must be provided in the base.
Welding hex nuts under the base is recommended.
The new positions of mounting holes for the motor base may interfere with stiffening ribs under
the base. Welding the motor base in position is recommended.
DESCRIPTION
Operating Mechanism
Cross sectional views (Figures 4 & 5) have been included in the back of this manual to assist in
repairing the pump and identifying the parts. It many be helpful to refer to this illustration and
to Figure 2 in order to better understand the following paragraphs.
Each pump in the KDH series is air or water-cooled, single stage, and of the cam and piston
type. In order to balance the moving parts, the pump cylinder is internally divided into two sec-
tions having a common inlet and discharge.

4
Within each section is a piston which is driven by a cam. The cams are mounted 180° apart on
a single shaft so that the centrifugal forces of the moving pistons will oppose one another. The
shaft passes through the center wall separating the two pump sections and is supported in bear-
ings in the heads at each end of the cylinder. The open head, through which the shaft extends,
has a shaft seal to prevent air leakage into the pump, and an outboard bearing to handle belt
pull.
Each piston has an integral hollow extension (called a slide) which extends through a slidepin.
One side of the slide contains diagonal slots; as the slide passes back and forth through the slide
pin, these slots are covered and uncovered to form an inlet valve. Outlet valves are mounted
over the discharge port on top of the cylinder. All working parts are precisely machined to suit-
able clearances for high vacuum requirements.
Inlet and Outlet Valves
The covering and uncovering of the slots in the piston slide by the slide pin constitutes a me-
chanical inlet valve. Air or gas is admitted through these slots from the high vacuum side of the
slide pin into the space between the piston and the cylinder at certain parts of the cycle. As
there is no spring loading, no pressure difference is required to operate this valve. The outlet or
discharge valve is opened automatically by the compression of air or gas in the pump against
atmospheric pressure, plus a light spring pressure.
Sealing and Lubrication
Since the success of the pump depends on its being sealed and lubricated, an oil separator tank
is mounted above the pump just to one side of the valve chamber. From here on, the word oil
will be used to refer to the liquid which seals and lubricates the inside surfaces of the pump. Oil
is generally used except for special conditions as noted under Sealing Oils in this section.
Sealing Oils
Kinney Type AX oil is recommended for all applications compatible with mineral oils. Other
liquids many be suitable for special conditions.
The sealing oil should be free from gases or moisture. Otherwise, the vapors will be pulled out
of the oil and will prevent obtaining low absolute pressure. See Gas Ballast section, page 5.
Operating Cycle
The operating cycle of the Kinney pump is shown by cutaway views in Figure 1. In view A the
piston moving in the direction of the arrow is rapidly creating more space into which some of
the gas is admitted through the inlet port; at the same time the compression of the gas previ-
ously trapped is taking place on the opposite side of the piston. In view B the piston has almost
reached the end of the discharge, expelling all air or gas and surplus sealing oil through the out-
let valve (poppet type) and nozzle into the separator tank. The tank is where the oil is retained
and the air or gas admitted to the full space created is trapped and then expelled in the manner
as previously described.

5
Throughout the operating cycle, the cylindrical part of the piston is always close to, but not
touching the bore of the pump cylinder. In this small gap, an effective oil seal is built up ahead
of the piston, which in addition to the film of oil between the ends of the piston and face of the
heads, as well as the slide pin clearances, prevents leakage from the compression or atmospheric
side to the vacuum side. Re-expansion is reduced to a minimum, a condition essential to low
ultimate pressure and high pumping speed over a large pressure range.
Gas Ballast
Gas ballasting may be used to reduce the number of oil changes caused by contamination of oil
by condensable vapors or gases. Vapors or gasses such as water vapor, acetone, alcohol, kero-
sene and others, may be drawn over from the system and condensed in the pump. The gas bal-
last line admits atmospheric air to the compression space during part of the compression cycle
to prevent such condensation. See OPERATION for more details.
Dynamically Balanced Pump
The term “dynamically balanced” applies to pumps which have been specifically balanced to
reduce vibration. The KDH series are dynamically balanced by having each cam a different
weight and adding counterweight to the pump sheave. The heavier cam is installed on the open
head or drive shaft end of the pump. When reassembling a pump or ordering parts, be careful to
distinguish between the heavy or open head cam and the light or closed head cam. Always use
the correct counterweighted sheave.
Figure 1: Operating Cycle of KDH Series Single Stage Pumps

6
INSTALLATION
Warning: Disconnect the pump from source electrical power prior to making repairs or adjust-
ments to any electrical components of the unit.
Mounting the Pump
The pump unit should be mounted on a suitable rigid foundation and securely fastened down.
Connecting the Cooling Water
Caution: Do not allow the cooling water to freeze.
The pump is water jacketed. A small water line, with control valve, should be connected to the
water inlet on the suction side of the pump. The water outlet is on top of the cylinder near the
open head end, and should preferably be piped into an open funnel so that the operator can tell
if water flow and temperature are satisfactory. Control the water flow so as to have the dis-
charge water between 95° and 110°F when the incoming water is between 50° and 70°F. Where
the water is extremely cold, control the flow so that the pump runs just warm to the touch.
Vacuum Piping
For best results it is important that the inlet or vacuum pipe line to the pump be as large and
short as possible. It should not be smaller than the inlet port to the pump.
The best piping for the vacuum side of the pump is made up with flanges using neoprene
gaskets or O-rings. Flanges may be welded or threaded to the pipe. If threaded connections are
used, Kinseal compound or Teflon tape should be used to seal threads up to one inch in
diameter. Heavy sealing compound such as Tite Seal may be used on threads ove one inch in
diameter.
Oil Separator Piping
The discharge from the oil separator may be piped out of doors or any place convenient. In any
case, be sure that the discharge line does not leave the separator vertically for any great length.
This would permit the vapors to condense in the pipe, drip back into the tank and contaminate
the oil.
Come out to the tank with a horizontal run to a drop-out tee, and then go vertically up if
necessary. Equip the tee with a drain cock to draw off condensate from time to time as
required. Oil mist eliminators (ome) are available to take the place of the piping. In addition
omes are reclaim oil lost in the discharge if not contaminated by water or process vapors.
Fill the oil separator with sealing oil through the filling elbow on the side of the oil separator.
Refer to the SPECIFICATIONS section for the quantity and type of oil required.

7
Figure 2: Typical Outline of KDH Pump

8
Electrical Connections
Connect the power supply to the motor. Refer to the Solenoid Valve Section for wiring dia-
gram for the solenoid valves.
Prestart Checks
1. Be sure that the suction lines are absolutely free of foreign matter and perfectly tight. Use
an inlet protection screen or drop out trap on new installations or where large welded piping
is employed.
2. Make sure that the pump discharge is not obstructed
3. Check that the cooling water is available and connected to the pump.
4. Check the oil level and adjust if necessary. Proper oil level is about 1/4 inch above the cen-
ter of the sight glass on the side of the separator.
5. Ensure that the oil solenoid valve is wired correctly.
6. Check for correct rotation of the pump. Facing the drive end of the shaft the suction is on
the left and rotation should be counter-clockwise. If the rotation is not correct reverse any
two wires at the motor terminals.
OPERATION
WARNING:
•The beltguard must be properly secured to the pump at all times while the pump is run-
ning.
•When operating the pump in an enclosed area it is necessary, for health reasons, that 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 within the
pump could cause severe damage.
Each pump is fully tested at the factory and the rated blank-off pressure should be attained once
the pump is correctly installed. Note that on applications requiring continuous operation at high
pressures (above 50 Torr), it is recommended that the pump be operated for 8 to 24 hours with
pump inlet at one Torr or less. This allows proper wear-in and seating of the discharge valves.
Starting the Pump
1. Avoid starting the pump with the suction line under vacuum
2. Close the vent valve if one is used.
3. Start the pump.
4. Turn on the cooling water and adjust the flow as shown in the specifications.
5. Adjust the gas ballast as required.

9
Stopping the Pump
1. Close the isolation valve in the suction line, if one is installed.
2. Vent the pump to atmosphere through a vent valve or the gas ballast valve.
3. Stop the pump.
4. Shut off the cooling water.
Changing the Oil
The pump temperature should be near normal operating temperature (140°F) to drain the oil
more easily. Run the pump for half a minute with the suciton open to atmosphere (e.g., with a
gauge connection open). Place a container under the drain valve in the oil separator and open
the valve until the oil is removed from the pump.
If the oil is being drained due to oil contamination it is advisable to drain the oil from the
discharge valve as well. This well or trough can be reached by removing the valve chamber
cover plate on the top of the pump.
When the oil has drained from the pump, close the drain valve and fill the pump with the
quantity and type of oil shown in the specifications. The oil level will show above the center of
the sightglass until oil is distributed throughout the pump.
Gas Ballast
The gas ballast valve is a manual valve located on top of the pump between the suction flange
and the drive end. A pipe connects it to both ends of the pump. See figure 2, page 7.
Oil sealed mechanical vacuum pumps can become contaminated by vapors (commonly water or
solvents) which have condensed and mixed with the oil. The contaminant vaporizes in the low
pressure suction space and prevents gas from being drawn into the pump which dramatically
impairs pump performance.
The gas ballast valve admits atmospheric air into the pumping chambers after they have closed.
This reduces low pressure pumping speed but increases gas temperatures, preventing vapors
from condensing. Opening the gas ballast valve can help avoid vapor contamination or recitfy
moderate vapor contamination. Heavy contamination may require changing the oil.
To remove vapor contaminants from the oil, isolate the pump from the system, fully open the
gas ballast valve and run the pump overnight. If this is not possible, open the gas ballast valve
during periods when this will not affect the process, such as during loading and unloading.
To estimate the time running with gas ballast open required to clean the oil, read the blank-off
pressure with the gas ballast valve closed then run for 5 or 10 minutes with the valve fully open.
Close the gas ballast valve and read the blank-off pressure again. Use the observed rate of
change to estimate the amount of time to achieve the desired blank off pressure.

10
It may be possible to run the pump continuously with the gas ballast valve partially open. Open
the valve until the blank-off pressure is slightly below the highest pressure level at which the
process can be performed. This is particularly useful in humid climates
Oil Separator
The oil separator acts as a baffle to prevent large oil droplets from being expelled from the
pump and it also forms a reservoir for oil; a sightglass indicates the oil level.
Water may condense in the separator tank and collect in the bottom. The oil feed line via the
solenoid valve to the pump protrudes above the bottom of the tank to avoid drawing water into
the pump. This water may be drained manually through the oil drain valve.
Where large quantities of water condense regularly, an automatic drain valve may be fitted.
Consult the factory for recommendations on how this may be fitted.
The oil separator may emit some oil smoke when the pump is operated at high pressure. This
can be avoided by fitting an oil mist eliminator to the top of the separator tank, and piping the
discharge from the oil mist eliminator.
SOLENOID VALVES
General
Valve bodies should be connected in the pipe line with the pressure drop across the valve in
such a direction as to hold the valve disk firmly on its seat when the valve is closed. The arrow
in the valve body indicates the proper direction of pressure drop.
Electrical Connections
Check the operating voltage of the solenoid valve and motor from the component nameplates.
If the solenoid valve is dual voltage make sure it is wired in accordance with the diagram on the
coil.
Overheating of Coils
Coils are designed to operate with about 50°F temperature rise. Since coils are furnished to
hold the valve open they should not exceed this temperature in normal operation. Hot smell or
smoke calls for investigation. First check for valve not opening due to low voltage. Failure of
the valve to open when energized will cause overheating.
Sticking and Jamming
Foreign matter may cause the valve to stick, jam or leak. Any solenoid valve should be cleaned
periodically. Solenoid valves should be cleaned when the oil is changed due to contamination
by foreign matter.

11
Wet Coils
Valves are designed for use in comparatively dry locations and in temperatures up to 115°F.
Weatherproof valves are available for wet locations and have threaded holes for the use of con-
duit.
Coil Replacement
Should a coil fail for any reason or if it is desired to change to a different voltage, this is easily
done without disturbing the piping. Take off the coil retaining clips and remove the ocil.
Noise
There is always a slight hum when the solenoid is working, like that of a small transformer. A
rattling noise when the coil first receives current may be due to dirt in the core space, which
should be cleaned out. When the solenoid opens properly a slight click may be heard as the
core hits the plug at the top of the core tube. If surrounding noise prevents hearing this, the fin-
gers may be placed on the nut at the top where a slight bump can be felt.
TROUBLESHOOTING
General
If the system is not operating satisfactorily, a few simple checks should be made before taking
the pump apart. The most common troubles causing poor vacuum air leaks into the system and
contaminated sealing oil.
Two types of vacuum gauges are used for testing vacuum equipment; total pressure reading
types such as the thermocouple gauge and the partial pressure McLeod gauge. The McLeod
gauge indicates the partial pressure of permanent gases. It is most useful in confirming the ab-
sence or presence of real leaks. The thermocouple gauge is preferable for leak checking and in-
dicating the degree of contamination.
Isolating Troubles
First, isolate the trouble to either the process equipment or the vacuum pump by performing the
following test:
Close the high vacuum valve or isolate the pumping unit from the process equipment by means
of a bland-off plate. Start the vacuum pump. Read the lowest pressure attainable at the pump

12
inlet with a McLeod gauge. This should be done about 10% lower than the operating pressure
needed. If the blank-off pressure is acceptable, the pump is functioning properly. The process
equipment is at fault. Proceed as directed in Checking Process Equipment. If the blank-off
pressure is too high, indicating that the pump is at fault, proceed as directed in Pump Test.
Note: A gauge reading differential of +/- 10% is normally acceptable.
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:
Pump down each segment of the process equipment individually, starting at the segment closest
to the vacuum pump.
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 feed-throughs, gauge tube fittings and nay other penetrations into the
vacuum portion of the process equipment. Check especially 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 perma-
nent repairs can be made at the same time.
Leak Checking Techniques
If a leak detector is not available, use the following methods to locate leaks:
Cover the suspected leaks with a low vapor pressure sealing compound such as Apiezon Q, or
Duraseal. Do this while pumping on the equipment and monitoring the pressure. A sudden de-
crease in pressure indicates that a leak has been covered. Repair leaks permanently as previ-
ously directed.
If the leak is large, causing pressures in the Torr range, use a fast acting thermocouple gauge in
conjunction with a probing medium such as acetone, alcohol, freon, or helium. Position the
vacuum gauge head downstream from the suspected leak and pump. When the pressure has
been reduced so that the gauge may be used, apply probing medium to suspected leak areas. (A
squirt gun or brush may be used for applying liquid probing media.) If the probing fluid is di-
rected at the leak or an area close to it, a sudden change in pressure will occur. Cover the sus-
pected leak with plastic sealing compound and continue leak checking until desired pressure is
obtained. Repair leaks.
If leak checking fails, disassemble and remake all demountable joints and connections using
new gaskets or vacuum sealing compound such as Kinseal.

13
Pump Test
To check the condition of the pump, measure the blank-off pressure as directed below using a
McLeod gauge. If possible, also read the blank-off pressure with a thermistor or thermocouple
gauge to check the condition of the pump oil.
To read the blank-off pressure:
1. Close off the pump inlet by means of a high vacuum valve or blank-off plate.
2. Connect a vacuum gauge to the pump side of valve or blank-off plate. Position it so that it
will not become flooded by pump oil, preferably in the blank-off plate facing into the pump
section.
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 reading are 5 to 50 microns, McLeod, and 10 to 100 microns, thermocouple.
The specification pressure is 10 microns, McLeod.
If the McLeod gauge reading is low and the thermocouple gauge reading is high, the pump oil is
contaminated. Change the oil and recheck 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 con-
tamination as a possible cause of poor pump performance. After changing the oil, recheck the
blank-off pressure.
If both the McLeod and thermocouple gauge readings are high, indication that the oil is not con-
taminated, the pump is leaking. Proceed as directed in Pump Leaks.
Pump Leaks
If the vacuum pump is suspected of leaking (after eliminating oil contamination as the cause of
poor performance), use plastic sealing compound to seal over suspected areas, and check pump
blank-off performance before making permanent repairs with Kinseal. If gasketed connections
are suspected, remake the connections. (Plastic sealing compound may be used to make tempo-
rary gaskets; theses should not be made too thickly since the material may be squeezed into the
pump.)
Check carefully around the head to cylinder joints, securing bolts, oil lines, plugs, bearing set
screws, and generally any penetration into the vacuum pumping portion of the pump. Check the
inlet connection for proper sealing. If this fails, check the shaft seal for mechanical defects,
such as cracked carbon washer or hardened rubber components. Refer to the Overhaul section
for details on disassembly and overhaul.

14
Solenoid Valve
If the pump has been operating for some time and the oil in the separator is cool while the pump
is hot, check the solenoid valve for proper opening. This is explained under Noise in the Sole-
noid Valve section, page 11.
Discharge Valves
The KDH-65, KDH-80, KDH-130, and KDH-150 use 1-1/2 inch diameter discharge valves.
The discharge valves are shown in Figure 5.
If the pump blank-off pressure is excessively high and the discharge valves are suspected as the
cause, check the discharge valves as follows:
1. Drain all the oil from the valve chamber and nozzle by removing the pipe plug on either end
of the valve chamber.
2. Remove the discharge valve cover and gasket.
3. Remove the valve deck securing screws and lift out the decks and valves.
Inspect the valves for damage or foreign material. Lift and snap the disc to check spring ten-
sion. Replace valves or parts as required. Note the order of disassemble so that parts can be re-
placed in the same order. When reassembling, do not use sealing compound at either the valve
deck or the valve deck cover gaskets.
Figure 3: Discharge Valve

15
To reassemble the flat spring type 1-1/2 inch discharge valve, proceed as follows:
1. Combine the six individual springs into three pairs, aligning the guide tabs in each pair.
2. Slide the first pair of springs on to the lift stop with the guide tab first. That is, with the guide
tab retaining groove between each spring pair so that the springs are spaced equally around the
valve.
3. Position the springs and lift stop over the seat and disc. Apply a small amount of Loctite AC
on the threads of the hex socket capscrew. Secure the valve assembly together with the screw.
Wipe any excess Loctite from the valve. With a seal-locking type screw, Loctite need not be
used.
4. When returning the discharge valves to the pump, check that each disc is free to move prop-
erly.
5. After installing the valves in the pump, check that the valve assemblies cannot be turned, indi-
cating that they are tightly in position.
Mechanical Shaft Seal
The shaft seal has a long, trouble-free life under normal conditions. However, it may be worn or
scratched on the sealing faces by contaminated sealing and lubricating oil, or by possible lack of
oil at some time.
To inspect the seal, remove the belts from the pump sheave. Remove the pump sheave and drive
key from the shaft. Remove shaft seal drain plug (underneath shaft seal housing, second from
shaft extension) and drain the oil. Then, disconnect the tubing.
Remove the capscrews holding the shaft seal housing to the end of the open head and draw off the
housing. This will leave the inner race of the roller bearing and part of the shaft seal on the shaft.
The floating seat and sealing ring (see cross section view) should stay inside the housing when the
housing is removed. Draw the rotating parts of the seal off the shaft; spring holder and snap ring
may be left on if the open head is not being removed. Inspect the running face of sealing washer
for dirt, scratches or grooves which might account for leaks through the seal. Look at the inside of
bellows to see that it is not cracked or grooved as it prevents leakage along the shaft. Look inside
the shaft seal housing at the face of floating seat to see that it is not grooved. To check sealing
ring, it is necessary to remove outboard bearing cap and push the ring out of the hole. If this is
done, check the roller bearing, roller assembly and the running face of the races. In reassembling,
if floating seat and sealing ring are out, be sure and put the sealing ring on the floating seal and
then coat the sealing ring with the oil. Push it into its hole in the shaft seal housing slowly and
carefully so that the ring will not roll. A crease across the sealing ring, or a dent or scratch in the
running face makes a direct leak through the seal. Even new seals may leak if installed carelessly.
Slide the moving seal parts back on the shaft, in order removed, up to the spring holder and snap
ring. Then clean the face of the flanges on the open head and the clean the shaft housing free of
old sealing compound. Apply a thin coat of new sealing compound and install the housing. Re-
install the roller bearing outer race, or roller assembly if removed, and pack with grease. Put the
outboard bearing cap on and tighten. Reconnect the tubing, put the key back in the shaft, mount
the pump sheave and put the belts back on.
Note: When replacing the shaft seal, the bearing and locknut should be replaced.

16
Stalling
Difficult pump starting may result from excessively low pump temperatures which can be
caused by leaving the pump cooling water flow on when the pump is stopped, or by exposing
the pump to low ambient temperatures. If this occurs, warm the pump to the minimum pump
starting temperature of 50°F.
If the pump stalls at any time, it may be due to a loose belt, lack of lubrication, solenoid valve
not opening, badly contaminated oil, or foreign matter in the pump. If the pump can be turned
over by hand, check belt tension as noted under the OPERATION section. If stalling is due to
lack of lubrication, the oil line has become plugged suddenly after operating for some time.
Check the opening of the solenoid valves as previously described. If conditions do not improve,
remove the oil seal lines and clean them, as they are probably plugged. If a check of the oils
shows that it is not badly contaminated, there could be foreign matter in the pump. The oil can
be changed, as covered under Changing the Oil, but if it is contaminated enough to stall the
pump, the inside of the pump must be cleaned. Cleaning or inspecting the inside of the pump is
a major operation, and is covered in the OVERHAUL section. The closed head end is easily
checked by closing off the oil, disconnecting the tubing to that end, removing the capscrews and
drawing off the head which permits drawing out the piston and slide pin. See OVERHAUL for
disassembly of the open head end.
MAINTENANCE
General
Because of different operating conditions, and applications, a rigid maintenance schedule can-
not be stipulated. Where possible, required maintenance is given on an operating hour basis.
Where this is not possible, experience or poor performance will dictate the need for mainte-
nance. A careful record of pump blank-off readings and process chamber pumpdown times
should be kept to aid in maintaining and troubleshooting this unit.
Pump Periodic Maintenance
Check the oil level daily for the first week of operation, and weekly thereafter. The oil level
should be about 1/4” above the midpoint on the sight gauge and change when the pump is oper-
ating normally. At high pressures, or with a gas ballast flow, the oil level should be appreciably
higher than it is when operating at low pressures, near blank-off. IF there are no changes in the
oil level, check for obstructed oil passages in all oil lines and solenoid valve.
Check the condition of the oil periodically by draining a small quantity of oil into a clean con-
tainer and visually inspecting it for solid or liquid contaminants. Change the oil when contami-
nated.
There is no fixed interval for changing pump oil, since applications vary widely. This can be
determined only by experience and/or by deterioration of pump performance.

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Cleaning Contaminated Process Equipment
Process equipment contamination which may result in poor chamber pressures is often caused
by condensable vapors such as water vapor and can readily be removed. An extremely long
pumping cycle indicates severe contamination; a moderately longer than normal cycle indicates
slight contamination. Operating experience is usually the best guide.
If the contamination is heavy, operate the pumping equipment on process equipment overnight.
Open the vacuum pump gas ballast valve to prevent pump oil contamination.
If the contamination is slight, operate for a few hours with gas ballast. Application of gas bal-
last during processing will eliminate or reduce oil contamination.
If the process equipment is heavily contaminated, wipe down the chamber walls with cloths
soaked in ethyl alcohol, acetone, or other solvent. When starting the pumping equipment, open
the gas ballast valve to avoid pump oil contamination.
Note that the initial pumpdown cycle will be longer than usual due to the evaporation of the
cleaning fluid. Once the working pressure is reached, subsequent pumpdown cycles should be
normal.
OVERHAUL
General
Arrangements for repair service can be made with Tuthill Vacuum Systems (TVS) to either re-
pair pumps on site or return them to the manufacturer or other local service centers for repair.
Call TVS (800-225-3810) for service locations and for the proper procedure to return a pump
back to the factory for repair.
KDH-130B Disassembly
1. Drain oil and water.
2. Remove oil and gas ballast lines.
3. Remove CE (closed end) cap and CE head.
4. With the cam and piston towards the bottom of the cylinder bore, remove the piston and
slide pin.
5. Remove clamping plate, locknut and shaft seal housing.
6. Knockout bearing, backup ring and seal seat from shaft seal housing.
7. Remove seal assembly and retaining ring from shaft.
8. Remove OE (opened end) head. Do not remove piston and slide pin at this time.
9. Remove CE head cam by using pullers and eyebolts on cam or tapping shaft through
cam being careful not to damage the end of the shaft.
10. With the cam and piston towards the bottom of the cylinder bore, remove the piston and
slide pin on OE head side.

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11. Remove slide pin from piston.
12. Remove shaft and cam.
13. Remove cam from shaft if replacing one or the other.
14. Remove valve chamber cover and gasket.
15. Remove valve hold down plates and valves.
16. If water jacket needs to be cleaned, remove side cover and bottom plate and gaskets.
KDH-130B Reassembly
Before reassembling pump, clean and de-burr all mating surfaces. Apply a thin film of oil on all
internal parts and inside of cylinder bores as parts are reassembled. When looking at the OE of
the cylinder, the suction flange is to the left side.
1. Replace bearings in both heads.
2. Replace valves and valve hold down plates using new bolts with self-locking nylon.
3. Attach valve chamber cover and gasket.
4. Attach CE head on dowel pins without using sealer using 4 bolts.
5. If OE cam was removed, replace keys if needed and press OE cam onto shaft with the
two threaded puller holes facing outward. The OE cam is the heavier of the two cams.
6. Insert the shaft and cam into cylinder until the CE head end of the shaft is into the CE
head bearing and the cam is up against the center wall.
7. Put the slide pin onto the tang of the piston. The wider two of the long edges of the slide
pin go towards the piston.
8. With the slots in the piston tang facing down, put the slide pin and piston onto the OE
cam.
9. Clean and apply kinseal to OE head and cylinder.
10. Attach OE head to cylinder. Tighten middle bolts first and work outwards.
11. Rotate shaft counter clockwise a few times. If it will not rotate completely around, re-
move OE head to check that slide pin is on the piston tang properly and that there is not
any foreign material inside that would stop piston from rotating.
12. Remove CE head.
13. Replace keys if needed and tap CE cam onto shaft with the two threaded puller holes
facing outward.
14. Replace the piston and slide pin as in steps #7 and #8.
15. Attach CE head as in steps #9 and #10.
16. Rotate shaft as in step #11
17. Attach CE cap with o-ring to CE head.
18. Lubricate o-ring on seal seat and insert seal seat into shaft seal housing.
19. Replace retaining ring and carefully slide seal assembly onto shaft. Be sure there are no
burrs on the shaft shoulder. Use vacuum grease or oil to lubricate shaft.
20. Attach shaft seal housing and o-ring to OE head.
21. Replace backup ring, bearing, locknut and bearing clamping plate.
22. Attach oil and gas ballast lines. Be sure lines and valves are clean and clear.
23. If removed, replace side cover and bottom plate and gaskets.

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Notes : To check the solenoid valve, run pump at blank-off. Note oil level in sight glass. Open
the gas ballast valve; the oil level should rise. Close the gas ballast valve and the oil level
should drop back to normal operating level. If the oil level does not change, it could be a faulty
solenoid valve or clogged oil lines.
When replacing the shaft seal, the bearing and locknut should also be replaced.
KDH-65 and 130 Disassembly
1. Drain oil and water.
2. Remove oil and gas ballast lines.
3. Remove CE cap and CE head.
4. With the cam and piston towards the bottom of the cylinder bore, remove piston and
slide pin.
5. Remove slide pin from piston.
6. Remove OE cap and shaft seal housing.
7. Remove bearing and seal seat from shaft seal housing.
8. Remove inner bearing race from shaft.
9. Remove seal assembly and retaining ring from shaft.
10. Remove OE head. Do not remove piston and slide pin at this time.
11. Remove CE cam by using pullers and eyebolts on cam or tapping shaft through cam be-
ing careful not to damage the end of the shaft.
12. With the cam and piston towards the bottom of the cylinder bore, remove piston and
slide pin on OE side.
13. Remove slide pin from piston.
14. Remove shaft and cam.
15. Remove cam from shaft if replacing one or the other.
16. Remove valve chamber cover and gasket.
17. Remove valve hold down plates, valves and gaskets.
KDH-65 and 130 Reassembly
Before reassembling pump, clean and de-burr all mating surfaces. Apply a thin film of oil on all
internal parts and inside of cylinder bores as parts are reassembled. When looking at the OE of
the cylinder, the suction flange is to the left side.
1. Remove set screws and replace the bearings in both heads. Apply kinseal to set screws
and screw them in until set screw is into but not through bearing.
2. Replace valves, valve hold down plates and gaskets using new bolts with self-locking
nylon.
3. Attach valve chamber cover and gasket.
4. Attach CE head on dowel pins without using sealer using 4 bolts.
5. If OE cam was removed, replace keys if needed and press OE cam onto shaft with the
two threaded puller holes facing outward. The OE cam is the heavier of the two cams.