TapFlo Metal Series Operation instructions

Metal Series
Diaphragm Pumps
Original Instruction
edition 2020
Read this instruction manual carefully,
before you install and operate the pump.
Pump models:
TX25
T/TX70
T/TX120
T/TX220
T/TX420
T/TX820

CONTENTS
IOM manual Tapflo Metal Series 2
0. GENERAL......................................................................................................................................... 7
0.1. Introduction................................................................................................................................ 7
0.2. Warning symbols ....................................................................................................................... 7
0.3. Qualification and training of personnel................................................................................... 7
1. INSTALLATION ............................................................................................................................... 8
1.1. Operation principle.................................................................................................................... 8
1.2. Receiving inspection.................................................................................................................. 8
1.3. Lifting and transportation......................................................................................................... 9
1.4. Storage........................................................................................................................................ 9
1.5. Foundation ................................................................................................................................. 9
1.6. Suction and discharge piping ................................................................................................... 9
1.6.1. Rotary connections .......................................................................................................... 10
1.6.2. Connection of suction pipe ............................................................................................. 10
1.6.3. Connection of discharge pipe ......................................................................................... 10
1.7. Health and safety ..................................................................................................................... 10
1.7.1. Protection ......................................................................................................................... 10
1.7.2. Explosion hazardous environments –ATEX................................................................... 11
1.7.3. Air pressure....................................................................................................................... 11
1.7.4. Noise level ........................................................................................................................ 12
1.7.5. Temperature hazards ....................................................................................................... 12
1.8. Air connection .......................................................................................................................... 12
1.8.1. Air treatment system ....................................................................................................... 13
1.9. Example of installation............................................................................................................ 13
1.10. Recommended installations................................................................................................ 14
1.10.1. Flooded ............................................................................................................................. 14
1.10.2. Self-priming...................................................................................................................... 14
1.10.3. Submerged ....................................................................................................................... 14
2. OPERATION .................................................................................................................................. 15
2.1. Before starting the pump........................................................................................................ 15
2.2. Starting and operation ............................................................................................................ 15
2.2.1. Dry running ...................................................................................................................... 15
2.2.2. Optimization of the pump lifetime ................................................................................ 15
2.3. Pump stopping......................................................................................................................... 16
2.4. Residual risks............................................................................................................................ 16
2.5. Disposal after expiration ......................................................................................................... 16

CONTENTS
IOM manual Tapflo Metal Series 3
2.6. Actions in emergency .............................................................................................................. 16
3. MAINTENANCE ............................................................................................................................ 17
3.1. When the pump is new or reassembled................................................................................. 17
3.1.1. Performance test.............................................................................................................. 17
3.2. Routine inspection ................................................................................................................... 17
3.3. Complete inspection ................................................................................................................ 17
3.4. Location of faults ..................................................................................................................... 18
3.5. Aluminium and cast iron –Disassembly of the pump .......................................................... 19
3.5.1. Before the disassembly procedure ................................................................................. 19
3.5.2. Disassembly procedure.................................................................................................... 19
3.6. Aluminium and cast iron –Assembly of the pump ............................................................... 21
3.6.1. Test run ............................................................................................................................. 22
3.7. Stainless steel –Disassembly of the pump ............................................................................ 23
3.7.1. Before the disassembly procedure ................................................................................. 23
3.7.2. Disassembly procedure.................................................................................................... 23
3.8. Stainless steel –assembly of the pump.................................................................................. 25
3.8.1. Test run ............................................................................................................................. 26
4. OPTIONS ....................................................................................................................................... 27
4.1. Drum pump –TD… .................................................................................................................. 27
4.2. Twin connections –TT….......................................................................................................... 27
4.3. Filter press pump –TF… .......................................................................................................... 28
4.4. Barrier pump –TB…................................................................................................................. 28
4.4.1. Guardian calibration procedure.......................................................................................... 29
4.5. Ball lifters –TL…....................................................................................................................... 29
4.6. Pump with integrated pulsation dampener –TXK…............................................................. 30
5. SPARE PARTS................................................................................................................................ 31
5.1. Aluminium and cast iron pumps............................................................................................. 31
5.1.1. TX25 - Spare parts drawing................................................................................................. 31
5.1.2. TX25 –Spare parts list ......................................................................................................... 31
5.1.3. TX70-TX420 –Spare parts drawing .................................................................................... 32
5.1.4. TX70-TX420 –Spare parts list ............................................................................................. 33
5.1.5. TX70-TX420 –Spare parts - Options .................................................................................. 34
5.1.6. TX820 –Spare parts drawing .............................................................................................. 36
5.1.7. TX820 –Spare parts list ....................................................................................................... 37
5.2. Stainless steel pumps............................................................................................................... 38
5.2.1. T70 –T120 - Spare parts drawing....................................................................................... 38

CONTENTS
IOM manual Tapflo Metal Series 4
5.2.2. T70 –T120 –Spare parts list ............................................................................................... 39
5.2.3. T220 –T420 - Spare parts drawing..................................................................................... 40
5.2.4. T220 –T420 –Spare parts list ............................................................................................. 41
5.2.5. Spare parts - Options........................................................................................................... 42
5.2.6. T820 - Spare parts drawing................................................................................................. 44
5.2.7. T820 –Spare parts list ......................................................................................................... 45
5.3. Stocking recommendation...................................................................................................... 46
5.4. How to order parts................................................................................................................... 47
5.5. Pump code................................................................................................................................ 47
6. DATA ............................................................................................................................................. 48
6.1. Capacity curves......................................................................................................................... 48
6.2. Capacity changes...................................................................................................................... 48
6.3. Technical data .......................................................................................................................... 49
6.4. Dimensions ............................................................................................................................... 50
6.5. Tightening torques .................................................................................................................. 52
6.6. Permitted loads on manifolds................................................................................................. 52
7. WARRANTY .................................................................................................................................. 53
7.1. Warranty form.......................................................................................................................... 53
7.2. Returning parts ........................................................................................................................ 54
7.3. Warranty ................................................................................................................................... 54

EC DECLARATION OF CONFORMITY 01/EC/MET/2017
Series:
T(…)25…; T(…)70…; T(…)120…; T(…)220…; T(…)420…; T(…)820…;
Serial numbers:
2013 - … (from 1301-…)
Manufactured by:
Tapflo AB
Filaregatan 4
4434 Kungälv, Sweeden
This declaration of conformity is issued under the sole responsibility of the manufacturer.
Object of declaration: AIR OPERATED DIAPHRAGM PUMPS
The object of the declaration described above is in conformity with the relevant Union
harmonization legislation:
•Directive 2006/42/EC of European Parliament and of the Council of 17 May 2006 on
machinery, amending Directive 95/16/EC;
Mr Michał Śmigiel is authorized to compile the technical file.
Tapflo Sp. z o.o.
ul. Czatkowska 4b
83-110 Tczew
Signed for and on behalf of
Tapflo AB
Håkan Ekstrand
Managing Director
Tapflo AB, 02.03.2017r

EU DECLARATION OF CONFORMITY 02/ATEX/AODD/2019
Series:
TX(…)9…; TX(…)20…; TX(…)50…; TX(…)100…; TX(…)200…; TX(…)400…; TX(…)800…;
TX(…)25…; TX(…)70…; TX(…)120…; TX(…)220…; TX(…)420…; TX(…)820…;
TX(…)30…; TX(…)80…; TX(…)125…; TX(…)225…; TX(…)425…; TX(…)825…;
TX(…)94…; TX(…)144…; TX(…)244…; TX(…)444…;
Serial numbers:
2019 - … (from 1911-…)
Manufactured by:
Tapflo AB
Filaregatan 4
442 34 Kungälv, Sweden
This declaration of conformity is issued under the sole responsibility of the manufacturer.
Object of declaration: CONDUCTIVE AIR OPERATED DIAPHRAGM PUMPS
EU Type Examination Certificate was carried out by J.S. Hamilton Poland Sp. z o.o. (Notified Body
No. 2057) and as a result a certificate No: JSHP 19 ATEX 0018X was issued.
The object of the declaration described above is in conformity with the relevant Union
harmonisation legislation:
•Directive 2014/34/EU of the European parliament and of the council of 26 February 2014 on
Equipment or Protective System intended for use in potentially explosive atmospheres
•EN ISO 80079-36:2016-07
•EN ISO 80079-37:2016-07
and is intended for operation in potentially explosive atmospheres according to:
II 2G Ex h IIC T6…T4 Gb
II 2D Ex h IIIC T60ºC…T125ºC Db
Signed for and on behalf of Tapflo AB
Håkan Ekstrand
Managing Director
Tapflo AB, 30.10.2019r

0. GENERAL
IOM manual Tapflo Metal Series 7
0. GENERAL
0.1. Introduction
The Tapflo Air Operated Diaphragm Pump range is a complete series of pumps for industrial
applications. The pumps are designed to be safe, simple and easy to use and maintain. The
construction is seal-less and without rotating parts. The pumps are suitable for almost all
different chemicals used by the industry today.
With proper attention to maintenance, Tapflo Pumps will give efficient and trouble free
operation. This instruction manual will familiarise operators with detailed information about
installing, operating and maintaining of the pump. AODD pump materials must be selected
carefully for each application. For more information, please contact Tapflo Group.
0.2. Warning symbols
The following warning symbols are present in this instruction manual. This is what they say:
This symbol stands next to all safety instructions in this instruction manual where
danger to life and limb may occur. Observe these instructions and proceed with
utmost caution in these situations. Inform also other users of all safety instructions.
In addition to the instructions in this instruction manual, the general safety and
accident prevention regulations must be observed.
This signal stands at points in this instruction manual of particular importance for
compliance with regulations and directives, for correct work flow and for the
prevention of damage to and destruction of the complete pump or its
subassemblies.
0.3. Qualification and training of personnel
The personnel in charge of installation, operation and maintenance of the pumps we produce
must be qualified to carry out the operations described in this manual. Tapflo shall not be held
responsible for the training level of personnel and for the fact that they are not fully aware of
the contents of this manual.

1. INSTALLATION
IOM manual Tapflo Metal Series 8
1. INSTALLATION
1.1. Operation principle
The Tapflo diaphragm pump is driven by compressed air. The two diaphragms are connected
by a diaphragm shaft and pushed back and forth by alternately pressurising the air chambers
behind the diaphragms using an automatically cycling air valve system.
The Suction Cycle:
➢Suction
One diaphragm creates a suction action in one chamber (on the right) when being pulled
back from the housing.
➢Discharge
The other diaphragm simultaneously transmits the air pressure to the liquid in the second
chamber (on the left) of the housing, pushing it towards the discharge port.
During each cycle the air pressure on the back of the discharging diaphragm is equal to the
head pressure on the liquid side. Tapflo diaphragm pumps can therefore be operated against
a closed discharge valve with no negative effect to the life of the diaphragms.
1.2. Receiving inspection
Although precaution is taken by us when packing and shipping, we urge you to carefully check
the shipment on receipt. Make sure that all parts and accessories listed on the packing list are
accounted for. Immediately report any damage or shortage to the transport company and to
us.

1. INSTALLATION
IOM manual Tapflo Metal Series 9
!
1.3. Lifting and transportation
Before handling the pump check the weight of the pump (see 6.3. Technical data). Refer to Your
local standards on how to handle the pump. If the weight is excessive to transport by hand it
must be lifted using slings and a suitable lifting device e.g. a crane or forklift.
Always use at least two slings and make sure they are secured in such a way to prevent the
pump from slipping and that the pump unit is hanging straight.
Never lift the pump with only one sling. Incorrect lifting can cause serious injury and/or damage
to the pump.
Never lift the pump under pressure.
Be careful that nobody passes under the pump when lifted.
Never try to lift the pump by the manifolds or hoses attached to the pump.
As an option pumps can be equipped with lifting eyebolts connected with the pump pin screws.
1.4. Storage
If the equipment is to be stored prior to installation, place it in a clean location. The pump
should be stored in an ambient temperature of 15°C (59°F) to 25°C (77°F) and relative humidity
below 65%. It should not be exposed to any heat source e.g. radiator, sun as this could result
in a negative way on the tightness of the pump. Do not remove the protective covers from the
suction, discharge and air connections which have been fastened to keep pump internals free
of debris. Clean the pump thoroughly before installation.
1.5. Foundation
The pump will operate properly without being fixed to a foundation. If fixation is needed for
installation purposes, make sure the foundation is able to absorb vibrations. It is essential for
the operation of the pump to mount the pump with the feet in a downward direction (see
sketch in chapter 1.8 “Example of installation”).
1.6. Suction and discharge piping
Suction and discharge piping should be fully supported and anchored near to but independent
of the pump. The piping connected to the pump should be a hose, to prevent undue stress and
strain on the pump connections and the piping.

1. INSTALLATION
IOM manual Tapflo Metal Series 10
1.6.1. Rotary connections
The suction and discharge connections can be rotated 180°. This simplifies the assembly
and installation of the pump. If you wish to rotate the connections, screw a threaded nipple
into the connection and rotate it. On the larger models T220, T420 and T820 it will be easier if
the housing nuts are slightly released while turning the connections.
1.6.2. Connection of suction pipe
Remember that the suction pipe/connection is the most critical point, especially if the pump is
priming. Just a small leakage will dramatically reduce the suction capability of the pump. When
connecting the suction pipe, the following is recommended:
1)
For satisfactory operation, use a reinforced hose (the suction power may otherwise shrink
the hose) or other flexible piping. The internal diameter of the hose should be the same
as on the suction connection (at the bottom of the pump) to have best suction capability.
2)
Make sure that the connection between the hose and the pump is completely tight,
otherwise the suction capability will be reduced.
3)
Always use as short suction pipe as possible. Avoid air pockets which can emerge with
long piping.
1.6.3. Connection of discharge pipe
For this connection it is only recommended to have a simple and positive flow connection. Use
a hose or flexible piping (minimum one meter) between the discharge connection and any rigid
fixed piping. Coil the hose at least one turn. All components (hose, pipe, valves etc.) on the
discharge piping must be designed for minimum PN 10.
1.7. Health and safety
The pump must be installed according to local and national safety rules.
The pumps are constructed for particular applications. Do not use the pump on
applications different from that for which it was sold without consulting us to ascertain
its suitability.
1.7.1. Protection
In the interest of health and safety it is essential to wear protective clothing and safety goggles
when operating, and/or working in the vicinity of Tapflo pumps.

1. INSTALLATION
IOM manual Tapflo Metal Series 11
1.7.2. Explosion hazardous environments –ATEX
The standard stainless steel pumps are not allowed to operate in environments where there is
danger of explosion. Static electricity may occur in the pump under operation, which may cause
explosion and injury. Special conductive TX pumps are available for such applications.
All our aluminium and cast iron pumps are by standard ATEX approved, having model names
TX… Follow below instructions and local/national rules for safe use.
ATEX (directive 2014/34/EU) classification of Tapflo TX pumps:
II 2G Ex hIIC T6…T4 Gb
II 2D Ex hIIIC T60ºC…T125ºCDb
Equipment group: II –all other explosive areas than mines;
Category group: 2–high level of protection (can be used in zone 1);
Atmosphere: G–gas;
D –dust;
Explosion group: IIC –gas group (such as acetylene, hydrogen);
IIIC –dust group (conductive dusts);
Type of protection: h–control of ignition sources;
Temperature class: T4, T6 –in the event of a malfunction, the maximum temperature of
asurface that may be exposed to gas T4 = 135°C, T6 = 85°C;
EPL protection level: Gb, Db –high protection.
Earth connection of the pump and other equipment
Connect a suitable earth wire to the stainless steel earth connection that is placed on the inside
of one of the pump housings. Connect the other end of the earth wire to earth and also make
sure that other equipment like hoses/pipes/containers etc. are properly earthed/connected.
Dry run in ATEX pump
ATEX approved pumps can run dry without increasing the risk of creating potential ignition
sources. Nevertheless, dry run periods should be decreased to minimum as they increase the
wear of parts inside of the pump. What is more, when running dry (e.g. during self-priming) the
pump should run at a low speed controlled via a needle valve.
Antistatic surface
Pumps in ATEX execution should be cleaned in order to preserve antistatic properties. Layer of
dust or other solid particles on the outer surfaces is unacceptable.
1.7.3. Air pressure
The maximum air pressure for Tapflo pumps is 8 bar. Higher air pressure than 8 bar can damage
the pump and may cause injury to personnel in vicinity of the pump. If you intend to apply a
higher air pressure than 8 bar, please consult us.

1. INSTALLATION
IOM manual Tapflo Metal Series 12
1.7.4. Noise level
At tests, the noise level from a Tapflo pump has not exceeded 85 dB(A). Under some
circumstances, for example if the pump is operating under high air pressure at low discharge
head, the noise can be inconvenient or hazardous for personnel staying for long periods in the
vicinity of the pump. This hazard can be prevented by:
➢using suitable ear protection;
➢lowering the air pressure and/or raising the discharge head;
➢leading out the outgoing air from the room by connecting a hose to the muffler
connection of the pump;
➢using elastomer valve balls (EPDM, NBR or polyurethane) instead of PTFE, ceramic or
stainless steel, provided that the elastomer is compatible with the pumped liquid.
1.7.5. Temperature hazards
➢Raised temperature can cause damage on the pump and/or piping and may also be
hazardous for personnel in the vicinity of the pump/piping. Avoid quick temperature
changes and do not exceed the maximum temperature specified when the pump was
ordered. See also general max temperatures based on water in chapter 5 “DATA”.
➢When the pump is exposed to ambient temperature variations or if there is big difference
between the temperature of the product and the surrounding, the tightening torques of
the housing nuts should be checked periodically as part of preventive maintenance. Please
contact Tapflo for tightening intervals recommendation.
➢If a hot product is pumped, the pump should not stand still when filled for a longer period
of time. This could cause leakage from the valves and contamination and/or damage of the
air valve.
➢Below 0°C (32°F) plastic materials become more fragile what can cause accelerated wear of
parts made of these materials. This is a hazard that has to be accepted when pumping such
cold products. Also in such case, when a pump is not operational it should be drained of all
liquid.
➢Bear in mind that the viscosity of the product changes with temperature. This has to be
taken into consideration when selecting the pump.
1.8. Air connection
Screw the air hose into the air intake on the centre block of the pump with for example a quick
release coupling. For best efficiency, use the same hose diameter as the internal diameter of
the connection on the air intake.

1. INSTALLATION
IOM manual Tapflo Metal Series 13
1.8.1. Air treatment system
The air valve is constructed for oil-free air. Lubrication of the air is not allowed. However, if the
air is very dry (laboratory air), the air may be lubricated with water. Maximum air pressure is 8
bar. As prevention purpose, a filtration of the air by means of a 5 micron filter or finer is
recommended. Recommended air quality according to PN-ISO8573-1:2010 is particles class 6,
water class 4 and oil class 4. Dirt in the air can under unfortunate circumstances be the cause
of a breakdown. If a compressor used to generate compressed air is not fitted with an air dryer
it is recommended to use a water separator to remove the extent of water from the prepared
air.
To facilitate the operation of the pump we recommend an air treatment system connected to
the air supply. These components should be included:
1) Regulator to adjust the air pressure;
2) Manometer to read the actual pressure;
3) Needle valve to adjust the air flow (especially when operating the pump in the lower range
of performance);
4) Filter.
These components are included in Tapflo’s Air treatment system which can be ordered from
us.
1.9. Example of installation
1) Gate valve compressed air
2) Filter and pressure regulator
3) Flexible hose
4) Needle valve
5) Flexible piping
6) Gate valve suction
7) Gate valve discharge
8) Coiled flexible piping
9) Flow gauge

1. INSTALLATION
IOM manual Tapflo Metal Series 14
1.10. Recommended installations
The Tapflo pump is flexible in the way you are able to install it. The in- and outlet ports can be
rotated more than 180° to fit various piping systems.
1.10.1. Flooded
The piping system is designed with a positive
suction head. This is the best way of
installation where it is necessary to completely
empty all liquid from the container, or where
viscous (thick) products are transferred.
NOTE! Do not exceed 0,7 bar suction
pressure! Higher pressure may cause
premature diaphragm failure and irregular
pump operation.
1.10.2. Self-priming
The Tapflo pump is designed to pull a high
vacuum. It is able to evacuate an empty
suction pipe without any damage to the
pump. The suction lift is up to 5 meters (16.4
ft.) from an empty suction pipe and up to 8
meters (26.2 ft.) from a wetted pipe. The
suction capability depends on the pump size
(see chapter 6 “DATA”).
1.10.3. Submerged
All Tapflo pumps may be submerged into the
liquid. It is important to make sure that all
components which are in contact with the liquid
are chemically compatible. The air exhaust
must be led to the atmosphere by means of a
hose.
NOTE!
Even if all above safety instructions are met and complied with, there still exists a minor danger
in the event of a leakage or mechanical damage of the pump. In such case the pumped product
can emerge on sealing areas and connections.

2. OPERATION
IOM manual Tapflo Metal Series 15
2. OPERATION
2.1. Before starting the pump
➢Make sure the pump is installed according to the installation instruction (chapter 1).
➢Before operating the pump, make sure that the valve on the suction side pos. 6 is
opened.
➢Filling of the pump with liquid before start is not necessary.
➢When installation is new or reinstalled, a test run of the pump with water should be
conducted to make sure that the pump operates normally and does not leak.
➢When installation is new or reinstalled, check the pump housing nuts tightening torque
(see chapter 6.5 Tightening torques). After approximately one week of operation, the
torque should be checked again. Please contact Tapflo for further tightening
intervals recommendation. This is important to prevent possible leakage.
2.2. Starting and operation
➢Open the discharge valve.
➢Note! Considering the suction capacity when air is still in the suction pipe, it is
recommended to start with low air pressure/flow (slowly) at the beginning. This
is not necessary if the pump is filled with liquid before start.
➢When the pump has been filled with liquid, the air pressure/flow may be raised in order
to increase the suction capacity of the pump.
➢The performance of the pump can be adjusted through the air supply by using a
needle valve and a pressure regulator. The performance can also be adjusted by
normal flow control on the discharge side of the system.
2.2.1. Dry running
Although the pump is prepared for dry running it is important to have in mind that long
periods of dry run may cause damage to the air valve and circlips. Also an empty pump
should operate at low speeds –controlled by a needle-valve.
2.2.2. Optimization of the pump lifetime
➢Running at full frequency (maximum air pressure/flow) continuously will cause
premature wear of the components. When there is possibility of the pump running dry
or/and at full frequency it is recommended to use an air valve with a PET piston. As a
general rule, we recommend to run at half of the maximum capacity of the pump. For
instance, a T120 pump should run continuously at maximum 80 l/min.
➢As stated in chapter 0Tapflo recommends to use an appropriate air treatment system
in order to extend the pump’s lifetime.

2. OPERATION
IOM manual Tapflo Metal Series 16
➢If the air humidity is high, use of a water separator or air dryer is recommended.
Otherwise on the air discharge side due to decompression, icing on the muffler can
appear causing it to shrink and eventually it can shoot out of its socket.
➢If the ambient air is humid, icing can occur outside of the muffler. In such case it is
recommended to use a longer exhaust of the compressed air (ca. 500 mm / 19,7’’).
➢If there is possibility of freezing at the air exhaust, it is good to pre-heat the air before
it reaches the air intake in order to raise the dew point of the air.
NOTE! Make sure that the air temperature does not exceed 50°C (122°F).
➢If icing / freezing is still a problem with the standard muffler, we recommend using our
heavy duty metal muffler. Contact us for more information.
2.3. Pump stopping
The pump can be stopped in two ways:
1) By closing of the discharge valve. The pressure from the system will stop the pump
automatically. The pump restarts easily when the valve is opened again.
NOTE! When using this method keep in mind that air must be supplied to the pump.
This is essential to keep the diaphragms in balance what protects them from premature
failure.
2) By cutting off the air supply.
NOTE! When using this method make sure that the discharge valve is opened to relief
the pumps pressure.
2.4. Residual risks
Even with proper application and observance of all points listed in this operating manual,
there is still an estimable and unexpected residual risk when using the pumps. It may leak,
fail due to wear, application-related causes or system-related circumstances.
2.5. Disposal after expiration
The metallic components like aluminium, stainless steel and carbon steel can be recycled.
Plastic parts are not recyclable and must be disposed of as residual waste. The pump must
be disposed of properly, according to local regulations. It should be noted that potentially
dangerous fluid residues may remain in the pump and can create a hazard to the operator
or the environment, therefore the pump has to thoroughly cleaned before disposal.
2.6. Actions in emergency
In case of transferred liquid leakage, the air supply have to be closed and the pressure
released. During spillage of an aggressive liquid, local and national safety rules must be
followed.

3. MAINTENANCE
IOM manual Tapflo Metal Series 17
3. MAINTENANCE
3.1. When the pump is new or reassembled
If the pump is new or reassembled after maintenance it is important to retighten the pump
housing screws / nuts (pos. 37) after a few days of operation.
Make sure to use the right torque –see chapter 6.5 Tightening torques.
3.1.1. Performance test
When installation is new, a test run of the pump should be conducted. Gauge the capacity at
specific air pressure/flow. This information is useful for checking performance in the future as
wear takes place. You will be able to set schedules for maintenance of the pump and to select
spare parts to be kept on stock.
3.2. Routine inspection
Frequent observation of the pump operation is recommended to detect problems. A change
in sound of the running pump can be an indication of wearing parts (see chapter 3.4 "Location
of faults" below).
Leaking liquid from the pump and changes of performance may also be detected. Routine
inspections should be conducted frequently.
3.3. Complete inspection
The intervals for a complete inspection depend upon the operation conditions of the pump.
The characteristics of the liquid, temperature, materials used in the pump and running time
decide how often a complete inspection is necessary.
Nevertheless, we recommend to inspect Tapflo pumps at least once a year by the end user.
Parts from KIT AIR and KIT LIQ should be changed during inspection.
See paragraph 5.3 for detailed kits content.
If a problem has occurred, or if the pump is in need of a complete inspection, refer to chapters
3.4 "Location of faults" and 3.5, 3.7 "Dismantling of the pump". You are of course warmly
welcome to consult us for further help.
Parts that are subject to wear should be kept in stock, see our recommendations in chapter 5.3
“Stocking recommendation”.

3. MAINTENANCE
IOM manual Tapflo Metal Series 18
3.4. Location of faults
PROBLEM
POSSIBLE FAULT
POSSIBLE SOLUTION
The pump does not run
The air pressure is to low
Increase air pressure via a filter-regulator
The air connection is blocked
Check / clean air supply connection
Muffler is blocked
Check / clean / replace muffler
Air valve is defective
Clean / replace complete air valve
Dirt in the pump chamber
Remove debris from the chambers
Diaphragm breakdown
Replace diaphragm
The suction is bad
Suction connection is not tight
Tighten the suction line
Suction connection is blocked
Clean suction line
Muffler is blocked
Check / clean / replace muffler
Valve balls are blocked or damaged
Check dimensions and shape of valve balls
Valve seats are worn
Pump starts with high pressure
Air in suction / discharge line
Dry suction against discharge pressure
Check dimensions and shape of valve seats
Start the pump slowly (see chapter 2.2)
Vent suction / discharge line
Wet the pump / start without discharge pressure
The pump runs irregular
Valve balls are blocked
Check dimensions and shape of valve balls
Sealing in centre block is worn
Air valve is defective
Replace sealing
Clean / replace air valve
Diaphragm breakdown
Valve seats are worn
Icing on the muffler
Replace diaphragm
Check dimensions and shape of valve seats
Improve air quality (see chapters 1.7.1 and 2.2.2)
Bad flow/pressure
Pressure fall in air supply
Pressure losses on suction side
Air supply / air valve leaking
Increase air pressure via a filter-regulator
Check/change installation on suction side
Check / repair / replace air supply / air valve
Suction or air connection blocked
Check / clean air supply / suction connection
Muffler is blocked
Check / clean / replace muffler
Valve ball worn or broken
Valve seats are worn
Check dimensions and shape of valve balls
Check dimensions and shape of valve seats
Air in liquid
Seal suction line; check / refill container
Diaphragm breakdown
Icing on the muffler
Check / replace diaphragms
Improve air quality (see chapters 1.7.1 and 2.2.2)
Liquid leaks from the pump
Screws on the housing not properly
tightened
O-rings on manifolds damaged
Damaged diaphragm
Tension / stress form the installation
Check tightening torques of the screws
Replace O-rings
Check / replace diaphragms
Adjust installation, eliminate stress, when using a
dampener provide separate support for it (see
dampener IOM manual).
Liquid comes out of the
muffler
Diaphragm breakdown
Replace diaphragm
Diaphragm breakdown
Wrong selection of material
Too high pressure in the installation
Long periods of dry running
Too high pressure on suction side
Contact us for information on material selection
Use air treatment system for protection
When dry, run pump slowly (see chapter 2.2)
Make sure there is pressure balance between the
air and liquid side of the diaphragm

3. MAINTENANCE
IOM manual Tapflo Metal Series 19
3.5. Aluminium and cast iron –Disassembly of the pump
The numbers put in brackets, refer to the part numbers in the spare part drawings and spare
part lists in chapter 5. “SPARE PARTS”.
3.5.1. Before the disassembly procedure
Be sure to drain all liquid from the pump. Cleanse or neutralize the pump thoroughly.
Disconnect the air supply and then the suction and discharge connections.
3.5.2. Disassembly procedure
Fig. 3.5.1
Unscrew the housing screws [37] on one side of the
pump.
Fig. 3.5.2
Carefully lift the “loose” pump housing [11].
Fig. 3.5.3
Remove the manifolds [13].
Fig. 3.5.4
Unscrew one of the diaphragms [15] from the shaft
[16].
Fig. 3.5.5
Flip the pump and unscrew the second housing [11].

3. MAINTENANCE
IOM manual Tapflo Metal Series 20
Fig. 3.5.6 For TX25 up to TX420
In order to take out the valve balls [23], unscrew the
valve ball stop [22] from the housing [11].
ATTENTION! The stoppers are tightened with a small
amount of glue. If unscrewing is difficult, heat up
slightly the housing to loosen the glue. Make sure the
allen key used is of good quality not to damage the
stopper socket.
Fig 3.5.7
Push out the shaft [16] from the centre block [12] and
unscrew the second diaphragm [15].
Fig 3.5.8 For TX70 up to TX820
If the shaft sealing [36] seems to be worn (internal
leakage of air is present), remove them together with
their back-up O-rings [47] by means of a pointing tool.
ATTENTION! Take extra care when carrying out of this
operation. If any scratches are made on the inner
surface of the centre body air leakage will occur. During
this operation, the sealing and O-rings usually get
destroyed so make sure you have spare parts at hand.
Fig 3.5.9
Using pliers remove both circlips [27] from the centre
block [12].
ATTENTION! While doing this, cover yourself with
your other hand, as the circlip easily flips away.
Fig 3.5.10
Press out the air valve [61] by means of a pressing
device. Be careful not to damage the brass edges of the
air valve.
The pump is now completely disassembled. Check all components for wear or damage and
replace if necessary.
When air valve is removed from the centre body check the external O-rings (6 x pos. 30)
condition and replace if necessary.