Electronic Liquid Weigher 2005

Operating Instructions
Electronic Liquid Weigher

Type KFW
Metering Systems - FillingMachines

Würschum GmbH ,D - 73760 Ostfildern
Hedelfinger Str. 33, Tel. 0711 / 44813 -0
Type KFW
 1997 Würschum GmbH –Hedelfinger Straße 33 –73760 Ostfoldern –Germany
Issued 05/2005
All rights reserved, particularly all rights of reproduction, distribution and translation. No part of this
document may be reproduced in any form (print, photocopy, microfilm or by any other process) except
with written permission of Würschum GmbH or stored, processed, copied or distributed using electronic
systems.
2 Würschum GmbH - P.O. Box 4144 - 73744 Ostfildern - Germany (Stuttgart) - Tel.: (0711) 44 813-0 - Fax: (0711) 44 813-110
Type KFW
Table of Contents
Preface to the operating instructions .......................................................................................5
1 Specified Use ...............................................................................................................................6

2 Brief description ..........................................................................................................................7
2.1 Versions ..............................................................................................................................7
2.2 Construction ........................................................................................................................7
2.3 Scope of supply ..................................................................................................................8
2.3.1 Special accessories for the filling device ...............................................................9
2.3.2 Special accessories for the discharge device ......................................................10
2.3.3 Other special accessories ....................................................................................10
2.4 Function ............................................................................................................................11
2.4.1 Filling ....................................................................................................................11
2.4.2 Weighing .............................................................................................................11
2.4.3 Discharging ..........................................................................................................12
2.4.4 Rinsing .................................................................................................................12
3 Technical data ...........................................................................................................................13

3.1 KFW electronic liquid weigher with plexiglass or stainless steel weighbins
(version capable of calibration, model PTB 9.461) ..........................................................13
3.1.1 Performance data and weight .............................................................................13
3.1.2 Load cell ..............................................................................................................14
3.1.3 Dimensions ..........................................................................................................15
3.2 Stainless steel bin weigher (version capable of calibration, model PTB 9.461) ...............16
3.2.1 Performance data and weight ..............................................................................16
3.2.2 Load cell ...............................................................................................................16
3.2.3 Dimensions ..........................................................................................................17
4 Safety .........................................................................................................................................18
4.1 Fundamentals, specified use ............................................................................................18
4.2 Operating safety ...............................................................................................................18
5 Transport, storage, installation, dismantling .........................................................................20

5.1 Transport, storage .............................................................................................................20
5.2 Unpacking .........................................................................................................................20
5.3 Installation .........................................................................................................................20
5.4 Dismantling, packing .........................................................................................................21
Würschum GmbH - P.O. Box 4144 - 73744 Ostfildern - Germany (Stuttgart) - Tel.: (0711) 44 813-0 - Fax: (0711) 44 813-110 3
Type KFW
6 Commissioning and Starting up, shutting down ..................................................................22

6.1 Initial start-up ....................................................................................................................22
6.1.1 Electrical connections ..........................................................................................22
6.1.2 Installing/connecting the hoses ...........................................................................24
6.1.3 Setting up the liquid weigher ................................................................................25
6.2 Shutting down ...................................................................................................................27
6.3 Restarting ..........................................................................................................................27
7 Maintenance ..............................................................................................................................29
7.1 Inspection ..........................................................................................................................29
7.2 Maintenance .....................................................................................................................29
7.2.1 Rinsing .................................................................................................................29
7.2.2 Pneumatic pressure .............................................................................................29
7.2.3 Capacitive limit switch on weighbin (optional)-Float switsch ...............................29
7.2.4 Discharge pump ...................................................................................................29
7.3 Repair ...............................................................................................................................30
7.3.1 Changing the lower flange/plexiglass cylinder on the weighbin ..........................30
7.3.2 Changing the pilot valve (solenoid valve) (see data sheet in section 12.1) .........31
7.3.3 Load cell –setting the stop screw ........................................................................32
8 Fault –finding ...........................................................................................................................33
9 Customer service ......................................................................................................................34
10 Other directions ........................................................................................................................34
11 Spare parts ................................................................................................................................34

11.1 Rinsing ..............................................................................................................................35
11.2 Load cell ...........................................................................................................................35
11.3 Filling device with weighbins ............................................................................................36
11.4 Discharge device ..............................................................................................................37
12 Liquid Weigher Attachments ...................................................................................................38

12.1 Electrical Attachments ......................................................................................................38
12.2 Mechanical Attachments ...................................................................................................38
Type KFW
Preface to the operating instructions

These operating instructions are intended to help you to familiarize yourself with the liquid weigher and to
use it as specified.
They contain important information to enable you to operate the liquid weigher, safely, correctly and
efficiently. By taking note of these instructions you will be able to avoid danger, reduce repair costs and
downtime and increase reliability as well as the service life of the liquid weigher.
In addition you should supplement these instructions with the respective regulations on accident
prevention and environmental protection which are based on existing national regulations.
The operating instructions must always be available where the liquid weigher is used.
They must be read and applied by every person who is authorized to carry out work with or on the liquid
weigher, such as:
- Operation, including setting up, fault rectification during production, removal of liquid residues, and
the disposal of auxiliary materials.
- Maintenance, inspection repair and/or
- Transport.
Apart from these operating instructions and the valid and binding regulations for accident prevention in the
respective country and place of use, the recognized specialist technical regulations for safety and
specialist work must also be observed.
Explanation of symbols
The numbers in brackets after the descriptin of a detail in the text, e.g. (Fig. 1/6), give the item number (6)
in the corresponding figure (1).
The following symbols are used in the operating instructions to emphasize particularly important
information!
This warning symbol is shown at all the positions in the operating instructions which are affect
your safety. Follow this advice accurately or danger to personnel may arise or damage to
machinery could occur.

This symbol indicates an instruction which must be especially heeded in order to ensure fault-
free liquid weigher operation.
Type KFW
1 Specified Use
The KFW electronic liquid weigher is designed solely for weighbin homogenous liquids without
solid additives or for weighing hetrogeneous liquids with pigment particles up to a viscosity of 3
kg/ms (^ 3000 cP), depending on the version of weighbins.
Examples: concrete admixtures, iron oxide (slurry).
Foods and chemical substances must only be weighed in stainless steel weighbins
(materials V2A, V4A). Never use plexiglass weighbins for this purpose.
When weighing liquids containing plasticizer particles, corresponding plasticizer-resistant filling

and discharge hoses must be used.
Never use the KFW liquid weigher with aggressive or abrasive liquids!
The KFW liquid weigher may not be used in premises covered by explosion
protection legislation.
Specified use also includes the following of the operation instructions and observing the safety,
inspection and maintenance regulations.
Type KFW
2 Brief description
2.1 Versions
The modular design principle of the liquid balance permits a number of different versions and
possible combinations, e.g.
- liquid weigher with bracket for wall mounting

- liquid weigher with frame with floor plate
- liquid weigher with plexiglass weighbins (up to six bins of equal or varying size)
- liquid weigher with stainless steel weighbins (up to six bins of equal or varying size)
- liquid weigher with plexiglass weighbins and stainless steel receiving hopper
- stainless steel liquid weigher
- liquid weigher in protective cabinet
- liquid weigher with protective hood

These operating instructions describe a liquid weigher with frame with frame with
floor plate, two plexiglass weighbins and two discharge pumps. The information
which they contain is largely applicable to the other versions and applications as
well.
Any departing characteristics and data will be specifically mentioned in the

individual case.
2.2 Construction
The KFW electronic liquid weigher essentially consists of the following functional blocks.
- filling device with weighbin

- rinsing facility
- parallelogram with load cell
- discharge facility with blow-empty facility.
Type KFW
Fig. 1
2.3 Scope of supply

 complete liquid weigher preassembled with
- frame with floor plate or bracket for wall attachment
- parallelogram with built-in load cell
- attachment frame with weighbins mounted

 rinsing device

 discharge device with pump(s)

 preassembled air hose connections

 operating instructions
The actual scope of supply depends on the individual customer order.
Type KFW
2.3.1 Special accessories for the filling device
The following special accessories are available for the liquid weigher:
a) Filling pumps b) Distributor for fitting an additional non-return

valve
Type of Type of
l/min
weigher filling pump
KFW 5 ZD 12 V By 6 –12
KFW 12,5 ZD 24 V By 12 –24
KFW 25 ZD 36 V By 18 –36
KFW 50 ZD 36 V By 18 –36
Fig. 2
c) Pneumatic squeeze valve and butterfly valve d) Protective hood for rinsing and filling device
Fig. 3 Fig. 4
e) Capcitive limit switch or float

switch on weighbin for overflow
protection.
Type KFW
2.3.2 Special accessories for the discharge device
a) Y-piece for discharge b) Device for blowing the pressure line empty
Fig. 5 Fig. 6
c) Pressure governor on discharge squeeze valve to monitor operating pressure
d) Screw-in spray jets (e.g. for introducing the liquid into a concrete mixer)
2.3.3 Other special accessories
a) Terminal box with wiring prepared by manufacturer
b) Standard weights
 The electronic control system and the compensator are not included with the liquid weigher.
Type KFW
2.4 Function
Diagram of the liquid weigher and its peripheral components
solenoid
rins. valve
non - return
valve
Weigh-
load cell
bins
charge pump disch.-
squeeze
valve
lower
flange
frame non - return
valve
solenoid
valve
pneum. compr. air
disch.-
inclin. valve conn.
pump
Fig. 7
2.4.1 Filling
The charge pumps draw the liquids to be weighed out of their storage containers and pump
them into the weighbins via the non –return valve.
The time period for which each pump is active and the order in which the pumps are activated is
specified by the electronic control system.
If the liquid weigher is equipped with a pressure governor at the discharge squeeze valve, the
operating pressure of the squeeze valve can be checked and evaluated prior to filling.
2.4.2 Weighbin
The liquid introduced into the weighbins causes a change in their weight.
This change in weight is communicated to the load cell via the distortion-resistant parallelgo-
gram, which in turn reacts by changing its electrical resistance. The change in resistance is
recorded and evaluated by the electronic control system.
Once a specified weight has been reached in the weighing cylinder, the control system stops the
delivery of liquid and starts discharging if appropriate.
Type KFW
2.4.3 Discharging
The electronic control system activates the pilot valve, which in turn releases the pneumatic
discharge squeeze valve. The liquid in the weighbin can flow out or is drawn out by the
discharge pump and transported on.
Once the liquid has been completely drawn out of the weighbin, the control system stops the
discharge pump and closes both the discharge squeeze valve and the pneumatic inclination
valve located at the pump outlet. This prevents any residues from flowing back into the pump
outlet from the pressure line.
If the KFW liquid weigher is equipped with the appropriate optional device, the pressure line
which leads off can now be blown empty by releasing the solenoid valve at the compressed air
connection.
2.4.4 Rinsing
Rinsing is generally carried out using clean water and preferably after each weighing.
When the rinsing valve is activated water is sprayed into the weighbins via a spray jet.
This quantity of water can likewise be weighed and added to the mixing water during the
discharge process.
Type KFW
3 Technical Data
3.1 KFW electronic liquid weigher with plexiglass or stainless steel weighbins
(version capable of calibration, model PTB 9.461)
3.1.1 Performance data and weight
Liquid weigher with

KFW 5 KFW 12,5 KFW 25 KFW 50
1 cylinder (type)
KFW 12,5/12,5
Liquid weigher with KFW 25/25
KFW 5/5 KFW 5/12,5
2 cylinders (type) KFW 12,5/25
KFW 5/25
Liquid weigher with KFW 12,5/5/12,5 KFW 12,5/12,5/12,5
KFW 5/5/5
3 cylinders (type) KFW 5/12,5/5 KFW 5/25/12,5
Liquid weigher with
KFW 5/5/5/5 KFW 12,5/12,5/12,5/12,5
4 cylinders (type)
Max. capacity per
5,5 litres 15 litres 30 litres 60 litres
cylinder
Tare weight with 12 kg 16 kg 21 kg 23 kg
1 cylinder
Each further cylinder 5 kg 8 kg 14 kg 16 kg

Total weight with 34 kg 37 kg 43 kg 45 kg
1 cylinder
Each further cylinder 6 kg 9 kg 15 kg 17 kg

Max. discharge time 6s 12 s 22 s 40 s
Type KFW
3.1.2 Load cell

 installed ready for use

 permanently adjusted overload protection and stop screw

 capable of calibration

 max. 1000 divisions

 sensitivity 2 mV/V

 weighing accuracy ± 0,1% relative to maximum weight
Liquid weigher - type KFW 5 KFW 12,5 KFW 25 KFW 50

Load cell, capable of 20 kg 50 kg 50 kg 100 kg
calibration
max. weight
Minimum unit 5g 10 g 25 g 50 g
(= e)
Range (50 e –max.) 0,25 –5 kg 0,5 –10 kg 1,25 –25 kg 2,5 –50 kg

 operating voltage 10 V direct current

 copper strand bypass to protect from excess voltage

 provided with 2 m screened cable
 For longer cabling use a terminal box and a sreened anticapacitance cable.
For further technical details of the load cells please refer to the accompanying assembly
i
nstructionsheaded“ LoadCel l
swi thSt r
ainGaugeSy stem” .
Type KFW
3.1.3 Dimensions
Fig. 8
E E
KFW A B C X ØD with with Ød Øe+Øf
1 cyl. n cyl.
5 1200 382 135 1800 133 400 18/25 12/18
12,5 1200 457 210 1800 200 400 n x (C+5) 18/25 12/18
25 1300 557 310 1800 300 400 25/38 12/18
50 1800 597 310 2400 300 400 38 18
Type KFW
3.2 Stainless steel bin weigher

(version capable of calibration, model PTB 9.461)
3.2.1 Performance data and weight
Bin weigher –type FW 100 FW 300 FW 600

Volume of weighbin 120 litres 330 litres 630 litres
Tare weight 35 kg 60 kg 75 kg
3.2.2 Load cell

 capable of calibration

 maximum 1000 divisions

 Operating voltage 10 V direct current

 sensitivity 2 mV/V

 weighing accuracy ± 0,1% relative to maximum weight
Liquid weigher –type FW 100 FW 300 FW 600

Load cell, capable of 200 kg 500 kg 1000 kg
calibration, max. weight
Minimum unit t 0,1 kg 0,5 kg 1 kg

(= e)
Range (50 e –max.) 5 –100 kg 25 –300 kg 50 –600 kg
For further technical details of the load cells please refer to the acompanying assembly
i
nstructi
onsheaded“ LoadCel l
swi t
hSt rai
nGaugeSy stem”.
Type KFW
3.2.3 Dimensions
Fig. 9
int. dimens. /mm Ø 500 800 800

A 750 1050 1050
B 1410 1550 2170
C 1650 1800 2400
D 550 850 850
E 830 830 830
F 150 150 300
G --- --- 830
H 140 140 140
K NW 80 NW 80 NW 100
Type KFW
4 Safety
4.1 Fundamentals, specified use

 The liquid weigher is constructed according to the latest technology and the recognized
technicalsafetyregul ati
ons.Howev erwheni tisuseddangercoul darisefortheuser ’
sl i
fe
and climb or those of a third party or damage to the machine or other equipment could
occur.

 Only use the liquid weigher in technically-perfect condition, it should also only be used
according to the specifications with full knowledge of safety and risks involved and taking
account of the operating instructions. In particular those faults, which could impair safety,
should be immediately rectified, or have such faults removed by others.

 The liquid weigher is exclusively specified for the applications given in Section 1. Any other
form of use, or a form which goes beyond this specification is deemed to be non-specified
use. The manufacturer/supplier will not be liable for damage resulting from such use. The
risk will solely be carrried by the user.

 The observation of these operating instructions and the following of inspection and
maintenance conditions are also part of specified use.
4.2 Operating safety

 Always have the operating instructions ready to hand where the liquid weigher is installed!

 In addition to the operating instructions you must observe and ensure that the generally
applicable, legal and other regulations for accident prevention and environmental protection
are followed!

 These duties can also for example include the handling of hazardous substances or the
provision/wearing of personal safety equipment/clothing.

 Supplement the operating instructions by instructions including supervisory and reporting
duties to take account of special operating circumstances, e.g. with respect to the work
organisation, working procedures, and the personnel employed. This is particularly true if
the liquid weigher is operated by handicapped personnel.

 The personnel charged with tasks on the liquid weigher must have read the operating
instruct i
onsbef orest artingwor kandi npar ticulart hesect i
onent itl
ed“ safet
yi nst
ructi
ons”.It
is too late to do this while working on it! This is particularly true for personnel who only work
on the liquid weigher occasionally, such as during repair work.

 You should occasionally check the personnel are still working with knownledge of the safety
aspects and inherent dangers and are taking account of the operating instructions!

 The personnel may not have long hair or wear loose or clothing or jewellery –including
rings. There is a risk of injury through being caught up in or pulled into the machinery.

 Insofar as is necessary or required by legislation –use personal safety equipment / pro-
tective clothing!

 Always ensure that a complete set of safety and danger instructions are kept at/on the liquid
weigher in a legible state! Provide new instructions in the event of damage or loss.

 If changes to the liquid weigher or its operating behaviour should occur which are relevant
to its safety it must be immediately stopped and the fault reported to the responsible person

 Do not carry out any alterations, additions or conversions to the liquid weigher, which could
impair safety, without the approval of the supplier! This is also valid for the installation and
setting up of safety equipment (e.g. eye protectors, side covers, protection sheets).
Type KFW

 Spare parts must correspond with the technical requirements laid down by the manufacturer. This is
always guaranteed in the case of original spare parts.

 It is absolutely essential to use the appropriate tools for the work when carrying out repair work.

 Work on or with the liquid weigher may only be performed by responsible personnel. Ensure that
they are above the minimum legally-responsible age!

 Only use trained and instructed personnel, clearly define the responsibilities for operating,
maintaining and repairing the machine!

 Ensure that only authorized personnel work on the liquid weigher!

 Only permit trainees, or persons still to be instructed in its use or those working within the
framework of a general training programme to work on the liquid weigher under the constant
supervision of an experienced person!

 Work on the electrical equipment of the liquid weigher may only be carried out by a specialist
electrician or by instructed people under the leadership and supervision of an electrical specialist
according to the electro-technical regulations.

 Nerver permit any work to be carried out in a way which is contrary to safety!

 Take precautions to ensure that the liquid weigher is always operated in a safe and functionable
condition!

 Do not use the liquid weigher unless all the safety devices and facilities required for safety are
present and functioning.

 At least once per shift check the liquid weigher for externally visible damage and faults. Report any
changes which have occurred (including changes in operating behaviour) to the person responsible
immediately. Shut down the liquid weigher straight away if necessary.

 In the event of functional faults, shut down the liquid weigher immediately and remove faults, or
have the faults removed by others.

 Before switching on always ensure that nobody is exposed to danger as the liquid weigher starts
up.

 Follow the setting up, maintenance and inspection tasks and schedules, as specified in the
operating instructions, including the information on the exchange of parts/components. These tasks
may only be performed by specialist personnel.

 Always retighten any threaded connections which have been undone during maintenance and
repair work.

 If it is necessary to dismantle safety equipment during conversion, maintenance or repair work, they
must be refitted and checked immediately after completion of the repair or maintenance work.

 Ensure that auxiliary materials as well as exchanged parts are disposed of in a safe and
environmentally –responsible way!

 The electrical equipment for the liquid weigher must be regularly inspected/tested. Faults such as
loose connections or slightly charred cables must be rectified immediately.

 When handling oils, greases and other chemical substances follow the safety advice which is valid
for that particular product.

 Even if only a slight change of location is made the liquid weigher must be isolated from any
external power supply. Before starting up again connect the liquid weigher properly to the mains
network via the motor circuit-breaker!
Type KFW
5 Transport, storage, installation, dismantling
5.1 Transport, storage
(1) The liquid weigher is dispatched in high –quality packaging. In order to avoid damage to the liquid
weigher, you must ensure that the packing container is neither dropped nor tipped on one side.
(2) Store the liquid weigher in a dry place. Use the original packing for this.
5.2 Unpacking
(1) Carefully unpack liquid weigher.

(2) Check liquid weigher for transport damage.
5.3 Installation
(1) Frame with floor plate:

Place liquid weigher on a stable, horizontal surface at the intended location and screw frame with
floor plate tight.
(2) Wall attachment bracket:
Screw bracket securely and firmly to wall. The screws must be able to bear the weight of the liquid
weigher including the liquid to be weighed in the weighbins in the long term.
(3) Remove the transport fixings:

 Unscrew the Allen screws of the wooden struts on the valve support.

 Remove wooden struts.
Ensure that the weigher does not suffer excessive vibration in the process.

 Do not throw away the wooden struts but keep them in a safe place. You will need them
again when transporting and re-packing the liquid weigher.
(4) Align the frame exactly using the water level.

(5) Ensure that the bellows on the discharge squeeze valve are arranged without stresses. Adjust if
necessary.
(6) Check hose connections and clips for correct and firm seating.
Type KFW
5.4 Dismantling, packing
(1) Shutdownl
i
qui
dwei
gherasperSect
ion6.
2“Shut
ti
ngdown”
.
(2) Attach transport fixings:
 Wedge wooden struts (use original parts if available) between valve support and bin support,
making sure the holes are in the right place.
 Screw the valve support to the bin support through the wooden struts using suitable screws.
(3) Disconnect all electrical connections leading off from the liquid weigher.
Work on the electrical cabling of the liquid weigher and the gear –type pumps must be
carried out by authorised and qualified personnel.
(4) Disconnect all hose connections leading off from the liquid weigher.
(5) Unscrew the screws of the frame (with floor plate) or wall attachment bracket.
(6) Pack liquid weigher into a solid wooden container and pad out the empty spaces suitably. To
avoid damage to the liquid weigher you must ensure that the packing container is neither tilted nor
tipped on one side.
Type KFW
6 Starting up, shutting up down
6.1 Initial start –up
Initial start –up involves the following steps:

 Installation → seesect
ion5.
3

 Electrical connections → seesect
ion6.
1.1

 Connecting the hoses → seesect
ion6.
1.2

 setting up the liquid weigher → seesect
ion6.
1.3
6.1.1 Electrical connections
Work on the electrical cabling must be carried out by authorised and qualified personnel.
Before starting work ensure that all conducting parts, connectors and terminals are free of
voltage.
6.1.1.1 Liquid weigher prewired by manufacturer
A terminal box is attached to the frame of the liquid weigher. The connections of all the electrical
components are taken to the terminal strip of this terminal box. This also applies to the discharge
pumps, which are operated with 230/400 V, 50 Hz. A terminal connecting plan is included with
the terminal box.
6.1.1.2 Liquid weigher without wiring
All the electrical components are wired by the customer. Use a suitable waterproof and dirt-re-
sistant terminal box. Section 12.1 contains data sheets and information sheets for the add –on
electrical parts of the liquid weigher.
Type KFW
The electrical components which are to be wired are:
Fig. 10
Part no. Description
8 Load cell Continue with screened, anticapacitance cable.
20.1 Pilot valve for discharge squeeze valve
31 Rinsing valve
35.1 Pilot valve for inclination valve on discharge pump
38 Solenoid valve of blow –empty device
39 Capacitive limit switch for overflow prevention (or float switch)
40 Pressure governor for operating pressure of discharge squeeze valve
Type KFW
Installing/connecting the hoses
a) Installing the filling hoses b) rinsing
(1) The filling hoses must be connected from (1) Tighten adjuster (Fig. 12/30.2) of pressure
beneath to the hose nozzles provided for reducer.
the purpose (11/24).
(2) Push hose of rinsing water supply onto
(2) The filling hoses must not be installed nozzle (Fig. 12/55) of inclination valve.
higher than the top edge of the weigher. Ensure a firm fit.
(3) Push filling hoses onto nozzles (Fig. 11/ (3) Tighten hose clip.
24). Ensure a firm fit.
(4) Adjust the maximum operating pressure of
(4) Tighten hose clip. the rinsing water (see section 6.1.3.2
“Mechani calSet t
ings”).
Fig. 11
c) Pneumatics for discharge squeeze valves

and inclination valves Fig. 12
(1) Push pneumatic hose onto nozzle

(Fig. 13/27.2) of pressure reducer.
(2) Tighten hose clip.
(3) The pressure reducer is set in the factory
to a max. of 4 bar.
Fig. 13
Type KFW
6.1.3 Setting up the liquid weigher
6.1.3.1 Electrical settings
a) Load cell
The load cell is preset in the factory. It is not necessary to readjust it during start-up.
For technical details of the load cell please refer to the accompanying assembly instructions
headed“ Loadcel l
swi thSt r
ainGaugeSy st
em” .
b) Capacitive limit switch –float switch (optional)
Both switches are used to provi de the cont r

olsy st
em wi tht he signal“ weighbinf ul
l”
.Thi s
monitoring device can be used to provide overflow protection at the control system. The data
sheetfort hecapaci t
iveli
mi tswi
tchorf loatswitchmaybef oundi nsect i
on12“Add-on parts for
theli
qui dweigher ”
.
c) Pressure governor on the discharge squeeze valve (optional)
This pressure governor monitors the operating pressure of the pneumatic discharge squeeze
valve.
Switching points: 3 bar rising/2 bar filling. These signals can be evaluated appropriately by the
controlsystem.Thedat asheetf ort hepr essuregov ernormaybef oundi nsection12“ Add-on
partsf ort
heliquidwei gher ”.
6.1.3.2 Mechanical settings
a) Load cell
The load cell (Fig. 14/8) has a mechanical overload

protection (Fig. 14/6) and a stop screw (Fig. 14/5).
Both are preset in the factory and do not need to be
readjusted during start-up.
Fig. 14
Type KFW
b) Rinsing –maximum operating pressure
(1) Ensure:

 that the hose of the rinsing water
supply is firmly attached to the nozzle
(Fig. 15/55) of the inclination valve.

 that the adjuster (Fig. 15/30.2) of the
pressure reducer is turned off.
(2) Connect rinsing water supply with > 4 bar

pressure.
(3) Open adjuster until the pressure gauge
(Fig. 15/30.1) indicates the maximum
operating pressure of 4 bar.
(4) Reduce the rinsing supply pressure some-
what.
 Typical operating pressure for water

rinsing: 2-4 bar.
c) Rinsing –distribution
(1) Set the stop –valve (Fig. 15/31.1) such that the two weighbins receive the same amount of rinsing
water.
d) Pneumatic pressure
The operating pressure for the discharge squeeze

valves is preset in the factory to a max. of 4 bar.
The compressed air supply for the inclination

valves is taken off immediately upstream of the
pressure reducer (Fig. 16/27.4).
(1) Ensure that the air hose is firmly attached

to the nozzle (Fig. 16/27.2) of the main-
tenance unit.
(2) Apply compressed air supply of the

inclination valves from min. 6 to max. 8 bar
at the nozzle (Fig. 16/27.2) of the
maintenance unit.
(3) Check that the operating pressure of the

discharge squeeze valves is no more than
4 bar at the pressure gauge (Fig. 16/27.1).
Type KFW
6.2 Shutting down
If the liquid weigher will not be used for a long period all liquids residues must be carefully rinsed
out of valves, hoses, weighbins and discharge pumps.
Drying out and hardening residues of liquids and dirt can impair the function of the valves, make
pumps difficult to run or block them and make seals hard to brittle.
The following steps are to be completed:
(1) Rinsing

 of the weighbins,

 of the dischrage squeeze valves and hoses,

 oft
hedi
schar
gepumps(
seeal
sooper
ati
ngi
nst
ruct
ionsunder“
Geary
-tpepump”
),

 of the valves and hoses on the pump delivery side.
(2) Attach transport fixings:

 Wedge wooden struts (use original parts if available) between valve support and bin
support, making sure the holes are in right place.

 Screw the valve support to the bin support through the wooden struts using suitable
screws.
(3) Switch off the liquid weigher so that it is free of voltage.
6.3 Restarting
Restarting after a long interval comprises the following steps:
(1) Remove transport fixings:

 Unscrew the Allen screws of the wooden struts on the valve Support.

 Remove wooden struts.
Ensure that the liquid weigher does not suffer excessive vibration in the process.

 Do not throw away the wooden struts but keep them in a safe place. You will need
them again when transporting and re-packing the liquid weigher.
(2) Apply operating voltage for pumps and valves and activate the control system.
(3) Adjust rinsing see section 6.1.3.2 b) and c).
(4) Adjust pneumatic pressure see section 6.1.3.2 d).
Type KFW
(5) i
onsheaded“
Check load cell (see also the accompanying assembly instruct Loadcel
l
swi
thSt
rai
n
GaugeSy stem” ).

 If the weighbins are empty, check the zero point on the control system and readjust the
control system if necessary.

 Using one or two standard weights check the linearity and the end value of the load cell
measuring range on the control system and readjust control system if necessary.
(6) Check the switching points of

 the pressure governor on the discharge squeeze valves (see section 6.1.3.1 c).

 the capacitive limit switch on the weighbins (see section 6.1.3.1 b).
Type KFW
7 Maintenance
7.1 Inspection
Any functional faults or peculiarities, noticed by operating personnel must be removed without
delay. In doing so the cause must be clearly established an effectively removed.
The following inspection work is to perform daily:
(1) Check screwed connections, hoses and valves are secure and tight.
(2) Check the lower flange of the weighbin for tightness.
(3) Check the alignment of the liquid weigher using the water level.
(4) Check gear –type pump for tightness and unusual running noises (see operating instructions
“
Gear-typepump” ,sect
i
on7) .
7.2 Maintenance
The following maintenance work must be carried out at least once a week. Otherwise the
machine cannot work properly.
7.2.1 Rinsing
(1) Check operating pressure (2-4 bar) and setting of the maximum pressure value (7 bar) see
section 6.1.3.2 point b).
(2) Check state of condensate in filter dish of pressure reducer and drain if necessary see section
12.
2“Mechani cal add –onpar ts” ).
7.2.2 Pneumatic pressure
(1) Check setting of maintenance unit is at pressure setting of 4 bar see section 6.1.3.2 point d).
(2) Check state of condensate in filter dish of pressure reducer and drain if necessary see section
12.
2(“Mechanical add –onpar ts” ).
7.2.3 Capacitive limit switch on weighbin (optional)
Check the switching function of the limit switch by filling the weighbin in question up to the
maximum filling level (see data sheet for the capacitive limit switch in section12.1“ El
ectri
caladd
–onpar t
s”).Ifafloatswi t
chi smount edCheck the switching function of the float switch by moving
up the float and check if the switch is working. If the float is dirty and not moving properly, you
have to clean the switch. Otherwise the weigher cannot work properly (see data sheet in section
12.1“El ectri
caladd-onpar t
s”).
7.2.4 Discharge pump
The maintenance steps for the discharge pump may be found in the accompanying operating
i
nstr
uct
ionsheaded“ Gear–t ypepump” .
Type KFW
7.3 Repair
Repair work requires specialist knowledge and particular skills which are not detailed in these
operating instructions.
Such work must therefore be carried out by qualified experts only.
7.3.1 Changing the lower flange/plexiglass cylinder on the weighbin
Different types of liquids to be weighed require different version of lower flange.
For example:
flat flange, tall flange,

e.g. for concrete admixtures e.g. for iron oxide paints (slurries)
Fig. 17
To change the lower flange/plexiglass cylinder, pro-

ceed as follows:
(1) Stop supply of liquid and rinsing water.
(2) Deactivate compressed air supply.
(3) Loosen upper hose clip (Fig. 18/20.1) on bel-

lows (Fig. 18/21).
(4) Loosen screwed connector (Fig. 18/20.1) and

pressure governor (Fig. 18/40) and remove air
hose.
(5) Unscrew complete weighbin from the angle

section and carefully remove from bellows.
Make sure the bellows are not damaged in

 the process.
(6) Loosen lower cap nuts (Fig. 19/16.2) of conrods

(Fig. 19/16.1) and remove lower flange (Fig.
Fig. 18 19/17).
Type KFW
(7) Apply Teflon tape to lower edge of the plexi-

glass cylinder to form a seal (Fig. 19/18).
(8) Place new lower flange on con –rods or insert

new plexiglass cylinder.
Make sure the Teflon tape seal is not
 squashed or damaged when inserting the

plexiglass cylinder.
(9) Apply cap nuts and carefully tighten crosswise.
(10) Screw on complete weighbin.
(11) Insert bellows.
Fig. 19
(12) Fit screwed connector (Fig. 18/20.1) with pressure governor and air hose.
(13) Tighten upper hose clip of bellows.
 Ensure that the bellows are not twisted or bent in the process!
(14) Activate compressed air supply, rinsing water and liquid supply.
7.3.2 Changing the pilot valve (solenoid valve)

(see also data sheet in section 12.1)
(1) Switch off compressed air supply.
(2) Unscrew connector (Fig. 20/a) from rinsing

head.
(3) Unscrew Allen screws (Fig. 20/b).
(4) Check whether the inlet and outlet holes of the

new valve each have an O-ring (Fig. 20/c).
(5) Place new valve in the appropriate location

ensure it is positioned correctly.
(6) Tighten Allen screws.
(7) Screw connector onto rinsing head.
Fig. 20
Type KFW
7.3.3 Load cell –setting the stop screw
The load cell is preset in the factory. In normal circumstances there will be no need to
change this setting.
If changes need to be made nonetheless (e.g. at the stop screw), proceed with the utmost
caution.
The stop screw may need to be readjusted if, for example, the area of movement of the
parallelogram is restricted by a stop screw which is set too high and weighing stops too soon.
Adjusting the stop screw:
(1) Remove protection sheet from the load cell,

revealing the parallelogram (Fig. 21/4) and
load cell (Fig. 21/8).
(2) Make sure that the stop screw (Fig. 21/ 5)

really is set too high.
(3) Loosen lock –nut (Fig. 21/5.1).
(4) Set stop – screw such that a gap of 1 –

(max.) 2 mm is retained between it and the
side of the parallelogram (Fig. 21/4).
(5) Tighten lock –nut.
Fig. 21
Type KFW
8 Fault –finding
Fault Possible causes Remedy

Pneumatic pressure drops, - Air supply too weak - Check pressure at maintenance unit
pressure governor reports (pressure gauge display)
pressure < 2 bar - Faulty discharge squeeze valve - Check and replace if necessary
(leakage)
- Faulty pilot valve (leakage) - Check and replace if necessary
- Air hose connection loose - Check and tighten if necessary
- Air hose porous or fractured - Establish cause (aggressive liquid,
hose jammed?) and replace hose
Liquid weigher fails to react - Transport fixings still fitted - Remove transport fixings (see
section 5.3“Instal l
ation”)
- Stop screw of load cell set too - Adjust stop screw (see section 7.3.3
high, restricting movement of “Loadcel l-adjusting the top screw
parallelogram
- Faulty load cell - Please contact Würschum Customer
Servi
ce( seesect ion9“ Customer
servi
ce”)
No empty signal despite - Transport fixings still fitted - Remove transport fixings (see
empty weighbin secti
on5. 3“ I
nstallati
on” )
- Bellows hardened by dirt - Clean bellows or repl. if necessary
deposits
- (Optional) protective cage rub- - Rearrange protective cage and
bing against load cell screw tight
- Liquid weigher not aligned using - Realign liquid weigher
water level
No full signal or incorrect full - Liquid weigher not aligned - Realign liquid weigher
signal using water level
- Capacitive limit switch: - Visually check switch LED on the
 response sensitivity set capacitive limit switch. If switch LED
incorrectly doesnotl ightwhen“ ful l
”l evelis
 faulty limit switch reached, readjust (see data sheet in
secti
on12. 2“Add-on parts for liquid
weigher ”).
- Replace limit switch
Type KFW
9 Customer service
Regular servicing by our company is not necessary as long as the operator reliably carries out
t
heser vici
ngi nstructi
onsasdescr ibedi nSect i
on7“ Maintenanceandser vi
cing”hi msel f
.
If necessary please contact our Customer Service office:
Würschum GmbH, Hedelfinger Straße 33, 73760 Ostfildern (Stuttgart)

Telephone +49 711-448 13 0, Fax +49 711-448 13 110
10 Other directions
Depending on the method of use and place of installation, the operator will need to specify
further information for the safe operation of the liquid weigher in the form of directions in the
empl oy ee’sownl anguagewhi char ebasedont heoper at
i
ngi nstructi
ons.Thesedi r
ect i
onsar et o
be posted at a suitable point in the workplace and followed by the employees.
11 Spare parts
For safety reasons always use original Würschum spare parts. If this is not possible
make sure that the spare parts used meet the technical requirements of Würschum
GmbH.
Please contact our Customer Service office in the event of queries.
In the event of queries, please contact our customer service department.
In order to ensure that we deal with your enquiry quickly, we require the following information:

 type and serial number of liquid weigher

 number and capacity of weighbins

 special accessories fitted, if any

 description and spare parts list number of part required

 quantity of parts required

 your address, telephone number and fax number
The parts listed in the following lists of spare parts from no. 50 onwards may vary
 depending on the version of liquid weigher.
Type KFW
11.1 Rinsing

30 Rinsing water pressure reducer
30.1 Pressure gauge
31 Solenoid Rinsing valve
31.1 Stop valve
32 T-piece½”–½”–⅜”
33 Spray jet
50 Connection pieces
53 Connection piece
54 Connection piece
Fig. 22
11.2 Load cell

4 Parallelogram
5 Stop screw
6 Overload protection
8 Load cell
9 Ball bearing
10 Electric bypass
Fig. 23
Type KFW
11.3 Filling device with weighbins
Fig. 24
Part no. Description Part no. Description

1 Frame 19 Scale
2 Plates for wall attachment 23 Filling hose
3 Valve support 24 Double nozzle
7 Support angle 25 Hose clip
13 Non –return valve 26 Water level
14 Filling pipe 26.1 Screw
15 Plexiglass cylinder 39 Capacitive limit switch
16 Upper flange 39.1 Splash guard for limit switch
16.1 Con –rod 56 Connecting pieces
16.2 Cap nuts 57 Connecting pieces
17 Lower flange 58 Hose clip
18 Seal (Teflon tape)
Type KFW
11.4 Discharge device
Fig. 25
Part no. Description Part no. Description

12 Frame for discharge connection 37 Pump motor
20 Discharge squeeze valve 38 Solenoid valve
20.1 Pilot valve 38.1 Non –return valve
21 Bellows 38.2 Y –piece
21.1 Hose clip 40 Pressure governor
22 Nozzle 59 Connecting piece
27 Pneumatic pressure reducer 60 Connecting piece
27.1 Pressure gauge 61 Connecting pieces
27.2 Connecting piece 62 Connecting piece
29 Pneumatic connection 63 Connecting piece
34 T-piece for ventilation 64 Connecting piece
35 Pneumatic inclination valve 65 Connecting pieces
35.1 Pilot valve 66 Connecting piece
35.2 Nozzle 67 Connecting piece
35.3 Elbow 68 Connecting pieces
36 Pump head
Type KFW
12 Liquid Weigher Attachments
12.1 Electrical Attachments

 Capacitive proximity switch or float switch on weighbin as overfill protection device

 Pressure governor on discharge squeeze valve for monitoring the operating pressure
of that valve.

 Solenoid valve 4/2 way valve.
12.2 Mechanical Attachments

 Pressure reducer complete with pressure gauge.

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Electronic Liquid Weigher 2005

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Operating Instructions

Electronic Liquid Weigher

Metering Systems - FillingMachines

 1997 Würschum GmbH –Hedelfinger Straße 33 –73760 Ostfoldern –Germany

Preface to the operating instructions .......................................................................................5

1 Specified Use ...............................................................................................................................6

3 Technical data ...........................................................................................................................13

5 Transport, storage, installation, dismantling .........................................................................20

6 Commissioning and Starting up, shutting down ..................................................................22

8 Fault –finding ...........................................................................................................................33

9 Customer service ......................................................................................................................34

10 Other directions ........................................................................................................................34

11 Spare parts ................................................................................................................................34

12 Liquid Weigher Attachments ...................................................................................................38

Preface to the operating instructions

- Maintenance, inspection repair and/or

Examples: concrete admixtures, iron oxide (slurry).

When weighing liquids containing plasticizer particles, corresponding plasticizer-resistant filling

- liquid weigher with bracket for wall mounting

Any departing characteristics and data will be specifically mentioned in the

- filling device with weighbin

2.3 Scope of supply

The actual scope of supply depends on the individual customer order.

2.3.1 Special accessories for the filling device

a) Filling pumps b) Distributor for fitting an additional non-return

e) Capcitive limit switch or float

2.3.2 Special accessories for the discharge device

c) Pressure governor on discharge squeeze valve to monitor operating pressure

2.3.3 Other special accessories

a) Terminal box with wiring prepared by manufacturer

Diagram of the liquid weigher and its peripheral components

3.1.1 Performance data and weight

Liquid weigher with

Each further cylinder 5 kg 8 kg 14 kg 16 kg

Each further cylinder 6 kg 9 kg 15 kg 17 kg

3.1.2 Load cell

Liquid weigher - type KFW 5 KFW 12,5 KFW 25 KFW 50

3.2 Stainless steel bin weigher

3.2.1 Performance data and weight

Bin weigher –type FW 100 FW 300 FW 600

3.2.2 Load cell

Liquid weigher –type FW 100 FW 300 FW 600

Minimum unit t 0,1 kg 0,5 kg 1 kg

Range (50 e –max.) 5 –100 kg 25 –300 kg 50 –600 kg

int. dimens. /mm Ø 500 800 800

4.2 Operating safety

5 Transport, storage, installation, dismantling

5.1 Transport, storage

(1) Carefully unpack liquid weigher.

(1) Frame with floor plate:

(4) Align the frame exactly using the water level.

5.4 Dismantling, packing

6 Starting up, shutting up down

6.1 Initial start –up

Initial start –up involves the following steps:

6.1.1 Electrical connections

6.1.1.1 Liquid weigher prewired by manufacturer

6.1.1.2 Liquid weigher without wiring