EN 13732:2002

SLOVENSKI STANDARD
01-julij-2003
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Food processing machinery - Bulk milk coolers on farms - Requirements for construction,
performance, suitability for use, safety and hygiene
Nahrungsmittelmaschinen - Behältermilchkühlanlagen für Milcherzeugerbetriebe -
Anforderungen für Konstruktion, Leistung, Gebrauchstauglichkeit, Sicherheit und
Hygiene
Machines pour les produits alimentaires - Refroidisseurs de lait en vrac a la ferme -
Prescriptions pour la construction, les performances, l'aptitude a l'emploi, la sécurité et
l'hygiene
Ta slovenski standard je istoveten z: EN 13732:2002
ICS:
65.040.10 Poslopja, naprave in oprema Livestock buildings,
za živino installations and equipment
67.260 Tovarne in oprema za Plants and equipment for the
živilsko industrijo food industry
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 13732
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2002
ICS 65.040.10; 67.260
English version
Food processing machinery - Bulk milk coolers on farms -
Requirements for construction, performance, suitability for use,
safety and hygiene
Machines pour les produits alimentaires - Refroidisseurs de Nahrungsmittelmaschinen - Behältermilchkühlanlagen für
lait en vrac à la ferme - Prescriptions pour la construction, Milcherzeugerbetriebe - Anforderungen für Konstruktion,
les performances, l'aptitude à l'emploi, la sécurité et Leistung, Gebrauchstauglichkeit, Sicherheit und Hygiene
l'hygiène
This European Standard was approved by CEN on 26 August 2002.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13732:2002 E
worldwide for CEN national Members.

Contents
page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions.6
4 List of significant hazards.9
4.1 General.9
4.2 Mechanical hazards .9
4.3 Electrical hazards .10
4.4 Hazards generated by materials and substances used.10
4.5 Hazards generated by neglecting hygiene principles in design.10
4.6 Hazards generated by neglecting ergonomic principles.10
4.7 Hazard arising from unexpected start-up.10
5 Requirements .11
5.1 General.11
5.2 Mechanical hazards .11
5.3 Electrical hazards .12
5.4 Hazards generated by materials and substances used.13
5.5 Hygiene .14
5.6 Ergonomics .18
5.7 Unexpected start-up .18
5.8 Other general requirements for tanks .18
5.9 Additional requirements for special tanks .21
6 Verification and tests.23
7 Information for use .27
7.1 General.27
7.2 Instruction handbook for the user .27
7.3 Instructions check list .28
7.4 Installation and maintenance instructions.28
7.5 Dismantling instructions.29
7.6 Minimum marking .30
Annex A (normative)  Noise test code (Grade 2 of accuracy) .31
Annex B (normative)  Test for cooling, thermal insulation, mixing tests.34
Annex C (normative)  Test for cleanability .46
Annex D (normative)  Sampling methods for milk mixing tests.54
Annex E (normative)  Equipment and installation for the tests for cleanability required in annex C .55
Annex ZA (informative)  Relationship of this document with EC Directives.60
Bibliography .61
Foreword
This document (EN 13732:2002) has been prepared by Technical Committee CEN/TC 153 "Food processing
machinery - Safety and hygiene specifications", the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical text or
by endorsement, at the latest by May 2003, and conflicting national standards shall be withdrawn at the latest by
May 2003.
This document has been prepared under a mandate given to CEN by the European Commission and the European
Free Trade Association, and supports essential requirements of EU Directives.
For relationship with the EU Directives, see informative Annex ZA, which is an integral part of this document.
In this European Standard the annexes A, B, C, D and E are normative.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland and the United Kingdom.
Introduction
This document is a type C standard as stated in EN 1070:1998.
The machinery concerned and the extent to which hazards, hazardous situations and events are covered are
indicated in the scope of this document.
When provisions of this type C standard are different from those which are stated in type A or B standards, the
provisions of this type C standard take precedence over the provisions of the other standards, for machines that
have been designed and built according to the provisions of this type C standard.
1 Scope
1.1 This European Standard specifies requirements for design, construction, performance, suitability for use,
safety and hygiene of refrigerated bulk bovine milk coolers and the related methods of test.
It applies to refrigerated bulk milk tanks with air cooled condensing units and automatic control intended for
installation on farms or at milk collecting points. It applies to tanks for two milkings (24 h), four milkings (48 h) and
six milkings (72 h), in which the cooling takes place totally or partially within the tank.
Performance requirements in 5.4.1.2.1 and 5.4.1.2.2 do not apply to tanks where cooling does not take place totally
within the tank nor where the tank is associated with a continuous system of milking (e.g. milking with robot).
1.2 This European Standard does not cover:
 mobile tanks;
 tanks intended to be tilted for drainage;
 equipment for delivering the milk to the tank;
 equipment for pre-cooling or instant cooling of the milk.
1.3 This standard covers significant hazards at machines falling within this scope when used as intended by the
manufacturer and as identified by risk assessment (see EN 1050:1997).
Noise is not considered to be a significant hazard for bulk milk coolers. This standard includes information in 7.1
and in annex A concerning the manufacturer's declaration of the noise emission level of the cooler.
1.4 This standard does not cover the calibration requirements for the tank to be used as a system for payment
purpose.
1.5 This standard applies primarily to the machines which are manufactured after its date of issue.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
EN 292-1:1991, Safety of machinery - Basic concepts, general principles for design - Part 1: Basic terminology,
methodology. (Identical with ISO/DIS 12100-1:2000)
EN 292-2:1991, Safety of machinery - Basic concepts, general principles for design - Part 2: Technical principles
and specifications. (Identical with ISO/DIS 12100-2:2000)
EN 378-1:2000, Refrigerating systems and heat pumps - Safety and environmental requirements - Part 1: Basic
requirements, definitions, classification and selection criteria.
EN 378-2:2000, Refrigerating systems and heat pumps - Safety and environmental requirements - Part 2: Design,
construction, testing, marking and documentation.
EN 378-3:2000, Refrigerating systems and heat pumps - Safety and environmental requirements - Part 3:
Installation site and personal protection.
EN 378-4:2000, Refrigerating systems and heat pumps - Safety and environmental requirements - Part 4:
Operation, maintenance, repair and recovery.
EN 1005-3:2002, Safety of machinery - Human physical performance - Part 3: Recommended force limits for
machinery operation.
EN 1070:1998, Safety of machinery - Terminology.
EN 1088:1995, Safety of machinery – Interlocking devices associated with guards – Principles for design and
selection.
EN 1672-2:1997, Food processing machinery - Basic concepts - Part 2: Hygiene requirements.
EN 10088-2, Stainless steels – Part 2: Technical delivery conditions for sheet/plate and strip for general purposes.
EN 50087:1993, Safety of household and similar electrical appliances, particular requirements for bulk milk coolers.
EN 60204-1:1997, Safety of machinery - Electrical equipment of machines - Part 1: General requirements (IEC
60204-1:1997).
EN 60529:1991, Degrees of protection provided by enclosures (IP code) (IEC 60529:1989).
EN 60947-2:1995, Low voltage switch gear and control gear – Part 2: Circuit-breakers (IEC 60947-2:1995).
EN ISO 3744:1995, Acoustics – Determination of sound power levels of noise sources using sound pressure –
Engineering method in an essentially free field over a reflecting plane (ISO 3744:1994).
EN ISO 4287, Geometrical product specifications (GPS) – Surface texture: profile method – Terms, definitions and
surface texture parameters (ISO 4287:1997).
EN ISO 4871, Acoustics – Declaration and verification of noise emission values of machinery and equipment (ISO
4871:1996).
EN ISO 11201, Acoustics – Noise emitted by machinery and equipment – Measurement of emission sound
pressure levels at a work station and at other specified positions – Engineering method in an essentially free field
over a reflecting plane (ISO 11201:1995).
ISO 2446:1976, Milk - Determination of fat content (Routine method).
ISO 2852, Stainless steel clamp pipe couplings for the food industry.
ISO 2853, Stainless steel threaded couplings for the food industry.
3 Terms and definitions
For the purpose of this European Standard, the terms and definitions given in EN 1070:1998, EN 378-1:2000, EN
1672-2:1997 and the following definitions apply.
3.1
refrigerated bulk milk tank
equipment for refrigeration, and bulk storage of refrigerated raw milk freshly milked
In following text, referred to as "Tank".
3.2
freshly milked
milk less than 2 hours after being milked
3.3
automatic control
arrangement by which the equipment functions under normal operating conditions, without requiring action by the
operator
3.4
atmospheric tank
tank of which the inner vessel is designed to operate at atmospheric pressure
3.5
vacuum tank
tank of which the inner vessel is designed to operate at a pressure below atmospheric pressure
3.6
agitator
device to mix the milk to promote heat transfer and to ensure uniform distribution of butterfat
3.7
reference position
position specified by the manufacturer for correct installation and operation of the tank
3.8
maximum volume (V )
m
volume to which the inner vessel in its reference position and without agitation can be filled without overflowing
(expressed in litres)
3.9
rated volume (V )
r
volume of the maximum permissible filling of the tank under operating conditions as stated by the manufacturer
(expressed in litres)
3.10
direct cooling system
cooling system in which the evaporator of the refrigerating system is in direct thermal contact with the milk or the
inner vessel
3.11
indirect cooling system
cooling system in which the heat is transferred from the milk to the refrigerant through a cooling medium
3.12
ice bank tank
tank with an indirect cooling system in which the cooling medium is water and ice is built on the evaporator
3.13
milking
quantity of milk (or testwater) which is equivalent to 50 % of the theoretical maximum daily milk production
3.14
tank for two milkings
tank intended to be emptied for milk collection each day and designed for cooling and storing its rated volume
every 24 h
3.15
tank for four milkings
tank intended to be emptied for milk collection every two days and designed for cooling and storing its rated volume
every 48 h
3.16
tank for six milkings
tank intended to be emptied for milk collection every three days and designed for cooling and storing its rated
volume every 72 h
3.17
operating conditions
state during which the tank is in use for the cooling and storage of milk in accordance with its design requirements
and all accessories are functioning effectively
3.18
ambient atmosphere
atmosphere surrounding the tank and in front of the air-cooled condenser of the refrigerating system
3.19
mean temperature
calculated average of the different temperatures (in Celsius degrees) of a medium (air, test water, milk) measured
at different measuring points, at the same time
3.20
ambient temperature
mean temperature of the ambient atmosphere (in Celsius degrees) (see B.1.3)
3.21
performance temperature (PT)
ambient temperature (in Celsius degrees) to be used when measuring the milk cooling time
3.22
safe operating temperature (SOT)
highest limit of the range of ambient temperatures (in Celsius degrees) at which the equipment is required to
function
3.23
initial temperature (IT)
mean temperature (in Celsius degrees) of the milk to be cooled at the time of the commencement of the cooling
test
3.24
storage temperature
mean temperature (in Celsius degrees) to which the milk to be cooled is reduced for storage
3.25
cooling time
time (in hours) required to cool a milking from initial temperature to + 4 °C
3.26
cooling cycle
period between two successive milk collections. For tanks for two milkings the cooling cycle is 24 h. For tanks for
four milkings the cooling cycle is 48 h. For tanks for six milkings the cooling cycle is 72 h
3.27
specific energy consumption
energy consumption in watt-hours per litre of cooled milk, measured as the mean consumption of all components
(excluding cleaning) during a cooling test under the test conditions appropriate to the performance class
3.28
milk
bovine mammary secretion obtained from one or more milkings without either addition thereto or extraction
therefrom, untreated and not standardised, complying with Code of principles concerning milk and milk products,
international standards and standard methods of sampling and analysis for milk products of the Joint FAO/WHO
Food Standards Programme
3.29
water
water, suitable for human consumption, meeting the requirements specified in the EC Directive 80/778/EEC
3.30
testwater (TW)
water used for test purpose in place of milk
NOTE The cooling time for water is nearly the same as that for milk.
3.31
filling
volume of the milk (or TW) in the tank
3.32
temperature of the milk (or TW)
mean temperature of the milk (or TW) at a particular moment (see B.1.5)
3.33
compact and plug in tank
tank where the condensing unit(s) is (are) mounted on the tank which leave(s) the manufacturer in a fully working
condition
4 List of significant hazards
4.1 General
This clause contains the hazards and hazardous situations based upon EN 1050:1997 as far as they are dealt with
in this European Standard, identified by a risk assessment significant for this type of machinery and which require
action to eliminate or reduce risk.
Before using this standard it is important to carry out a risk assessment of the bulk milk cooler to check that it has
the hazards identified in this clause.
4.2 Mechanical hazards
4.2.1 Hazards arising from operation of lids
Hazards of impact and crushing
Hazard of trapping inside the vessel: possibility of drowning.
4.2.2 Hazards arising from rotating parts of the agitator
Hazards of impact, drawing in and slipping
4.2.3 Hazards arising from the refrigerating system
Hazards arising from the refrigerating system are mentioned in the introduction of EN 378-1:2000, i.e.:
 injurious effects to persons caused by the generated low temperatures;
 bursting of pressurised parts by excessive pressure or temperature and by liquid expansion or liquid hammer;
 injuries from moving parts, fan blades, belts.
4.2.4 Hazards arising from loss of stability
Hazards of crushing and impact
4.3 Electrical hazards
Hazards of shocks by direct or indirect contact with live parts
4.4 Hazards generated by materials and substances used
4.4.1 Hazards arising from using chemical cleaning products and hot water
Hazards of skin or eyes burns, suffocation, irritation from contact or inhalation or ingestion when handling
hazardous cleaning products.
4.4.2 Hazards arising from refrigerant
Hazards arising from refrigerant are listed in the introduction of EN 378-1:2000.
4.5 Hazards generated by neglecting hygiene principles in design
4.5.1 Hazards arising from cooling and storage process of the milk in the tank:
 alteration of milk physical, biochemical, organoleptical properties;
 development of milk initial microbiological pollution.
4.5.2 Hazards arising from milk contamination
4.5.2.1 Physical and chemical contamination
Hazard of contamination of the milk and risks to the health of the consumer due to the presence of dust, insects
and other animals, foreign solid parts, water from streaming or outside cleaning.
4.5.2.2 Bad cleaning
Hazard of contaminating milk causing injury to health due to the presence or retention of chemical products, of
degraded milk, of microbiological pollution.
4.6 Hazards generated by neglecting ergonomic principles
Hazard of injury or chronic damage to the body resulting from awkward body postures, during operation, cleaning
and maintenance.
4.7 Hazard arising from unexpected start-up
By unexpected start-up, above mentioned mechanical, electrical and chemical hazards can occur.
5 Requirements
5.1 General
Machinery shall comply with the safety requirements and/or protective measures of this clause. In addition, the
machine shall be designed according to the principles of EN 292 for hazards relevant but not significant, which are
not dealt with by this document.
NOTE 1 5.1 to 5.6 give the safety requirements and/or protective measures relevant to 4.1 to 4.6;
5.7 concerns other requirements;
5.8 concerns additional requirements for special tanks.
NOTE 2 For hazards which are to be reduced by the application of a standard such as EN 378-1:2000, EN 378-2:2000,
EN 378-3:2000, EN 378-4:2000, EN 1672-2:1997, EN 60204-1:1997, etc, the manufacturer should carry out a risk assessment
to establish the requirements of this standard which are to be applied. This specific risk assessment should be part of the
general risk assessment of the machine.
Where the means of reducing the risk is by a safe system of working the machinery, the manufacturer shall include
in the information for use details of the system and of the elements of training required by the operating personnel.
5.2 Mechanical hazards
5.2.1 Lids
The opening, closing and locking operations shall require a positive action (examples: gravity, spring, hook,
balancing cylinder, …).
Hinged lids shall have a safe device to keep them in the open position.
It shall be clearly and visibly marked, adjacent to the manhole, that:
 before the closing of the cover, it shall be checked that nobody is in the vessel;
 before entering the tank, it shall be necessary to read the instruction handbook.
5.2.2 Agitators
5.2.2.1 General
No hazardous part of the agitator shall come into contact with the operator during the operation of the unit (see
5.2.2.2 and 5.2.2.3).
No projecting parts shall be present on the agitator shaft with the exception of the agitator blades and accessories
for the cleaning system.
5.2.2.2 Agitators attached to the lid
For agitator attached to the lid of a tank, an interlocking device e.g. a mercury switch, a gravity switch with positive
operation or a device complying with EN 1088:1995, shall be provided to automatically stop the agitator and
disconnect the power of the agitator before the hazardous parts of the agitator can be reached on when opening
the lid.
5.2.2.3 Agitators not attached to the lid
For agitators not attached to the lid, the tank shall be clearly and visibly marked to the lids to indicate that the
electrical supply of the tank shall be disconnected before entering the tank (see 7.5.6).
In order to allow inspections without danger inside the tank, an electrical disconnecting device (see 5.3.5) shall be
installed.
 For agitators with a mechanical power on the shaft P ‡ 200 W, a mechanical locking of the supply connecting
m
device e.g. a padlock or a key switch shall be provided.
 For agitators with a mechanical power on the shaft P < 200 W :
m
 either a mechanical locking of the supply connecting device shall be provided;
 or a warning panel shall indicate that it is forbidden to switch on the circuit breaking device while the
machine is inspected.
NOTE See 5.7. The same protective measure can be used for both requirements.
5.2.3 Refrigerating system
The refrigerating system shall comply with EN 378-1:2000 and EN 378-2:2000.
5.2.4 Stability
Tanks with a mass of 75 kg or more when empty shall be so constructed that under normal operating conditions, it
shall not tilt when subjected to an external force of 750 N applied at any accessible points, according to the test
method given in clause 6.
If the tank is equipped with a step or a platform, it shall not tilt when subjected to an external force of 1200 N
applied on this step or platform.
5.3 Electrical hazards
5.3.1 General
The electrical equipment shall comply with:
 either EN 50087:1993;
 or EN 60204-1:1997 and the following requirements 5.3.2 to 5.3.11.
5.3.2 Electromagnetic compatibility (see 4.4.2 of EN 60204-1:1997)
Where electrical/electronic components are used, the equipment shall not generate electromagnetic disturbances
above the levels that are appropriate for its intended place of use. In addition, the equipment shall have an
adequate level of immunity to electromagnetic disturbances so that it can correctly function in its intended place of
use.
NOTE Additional measures would be required to meet the conditions of the EMC Directive 89/336/EEC modified by
Directive 93/68/EEC.
5.3.3 Protection against electric shock (see clause 6 of EN 60204-1:1997)
The manufacturer shall pay attention to the possible wet conditions under which the equipment will be used and
shall give information in the instruction handbook relevant to electrical/supply requirements by using circuit-
breakers ensuring protection by residual differential current (RCD complying with annex B of EN 60947-2:1995).
For the degrees of protection: see 5.3.10.
5.3.4 Ambient air temperature (see 4.4.3 of EN 60204-1:1997)
Refer to the temperatures stated in 5.7.1 of this standard.
5.3.5 Supply disconnecting device (see 5.3 of EN 60204-1:1997)
A supply disconnecting device shall be provided.
If this device is not integrated to the machine, the instruction handbook shall precise clearly the conditions of
installation (see 7.3).
5.3.6 Power circuits (see 7.2.3 of EN 60204-1:1997)
An over current detection or interruption device only in the phase conductor is acceptable for single phase
machines.
5.3.7 Overload protection of motors (see 7.3 of EN 60204-1:1997)
For each motor rated at more than 0,5 kW, protection against motor overload shall be provided unless an analysis
of the equipment design and its foreseeable operating conditions determine that such protection is not necessary.
5.3.8 Control circuit supply (see 9.1.1 of EN 60204-1:1997)
Transformers are not mandatory for the control circuit supply of the tanks.
5.3.9 Emergency stop devices (see 10.7 of EN 60204-1:1997)
An emergency stop device is not necessary.
5.3.10 Degrees of protection
The protection classes shall comply with a minimum degree of IP X4.
5.3.11 Markings of control equipment (see 17.4 of EN 60204-1:1997)
The markings of control equipment shall be in accordance with 7.6.
5.4 Hazards generated by materials and substances used
5.4.1 Cleaning products used and hot water
The manufacturer shall include in the instruction handbook recommendations for compatible and incompatible
cleaning materials (see clause 7).
The design of automatic cleaning equipment shall ensure that no cleaning products and hot water can be splashed
or sprayed against an operator either during "pick up" of concentrated product or during the cleaning cycle (e.g.
hoses tightened (e.g. spanner) or tubing fastened (clips), shields over product dispensing units).
5.4.2 Refrigerants used
For the refrigerants used in the refrigerating system, EN 378-1:2000 to EN 378-4:2000 shall be applied.
5.5 Hygiene
5.5.1 Adequate cooling and safe storage of milk
5.5.1.1 Control and electrical equipment
The cooling of the first milking shall be started either manually or automatically. Then the control equipment shall
ensure that cooling starts automatically after commencing to add the second and following milkings.
The equipment for the control of the milk temperature shall operate satisfactorily (see 5.5.1.2.3 and 5.5.1.2.5) with
any volume of between 40 % of one milking and 100 % of the rated volume of the tank at milk temperature from
0 °C to + 35 °C and at any ambient temperature between + 5 °C and the SOT.
On a direct cooling system the agitator and the condensing unit of the refrigerating systems shall operate together
when controlled by the thermostat.
On an indirect system the agitator and the cooling medium circulation shall operate together when controlled by the
thermostat.
5.5.1.2 Cooling and agitation performances
5.5.1.2.1 Performance classes
The performance of a tank shall be specified according to the classification given in Tables 1 and 2, based on
batch filling.
5.5.1.2.1.1 Classification according to number of milkings
The numeral «2» shall designate a tank for two milkings.
The numeral «4» shall designate a tank for four milkings.
The numeral «6» shall designate a tank for six milkings.
5.5.1.2.1.2 Classification according to ambient temperature
Table 1 - Classification according to ambient temperature
Performance Safe operating
Classification temperature (PT) temperature (SOT)
°C °C
A 38 43
B 32 38
C 25 32
5.5.1.2.1.3 Classification according to milk cooling time
Table 2 - Classification according to milk cooling time
Specified cooling time for
Classification
all milkings from + 35 °C to + 4 °C
h
0 2
I 2,5
II 3
III 3,5
5.5.1.2.2 Milk cooling rate
If a tank for two milkings is either empty or contains 50 % of its rated volume of milk at + 4 °C, and 50 % of the
rated volume of milk at + 35 °C is added in one batch, all of the milk shall be cooled to + 4 °C in not more than the
specified cooling time.
If a tank for four milkings is either empty or contains 25 %, 50 % or 75 % of the rated volume of milk at + 4 °C, and
25 % of the rated volume of milk at + 35 °C is added in one batch, all of the milk shall be cooled to + 4 °C in not
more than the specified cooling time.
If a tank for six milkings is either empty or contains 16,7 %; 33,3 %; 50 %; 66,7 % or 83,3 % of its rated volume of
milk at + 4 °C and 16,7 % of the rated volume of milk at + 35 °C is added in one batch, all of the milk shall be
cooled to + 4 °C in not more than the specified cooling time.
The above requirements shall apply at ambient temperatures between + 5 °C and the PT.
5.5.1.2.3 Storage of the milk
Under normal operating conditions the storage temperature of the milk, between cooling periods shall be not higher
than + 4 °C. This requirement shall apply at ambient temperatures between + 5 °C and the PT.
5.5.1.2.4 Thermal insulation
The tank shall be provided with thermal insulation the efficiency of which shall be such that at the PT the rate of rise
of the mean temperature of the milk, initially at about + 4 °C, shall not exceed + 3 °C in 12 h when the rated volume
is allowed to stand undisturbed, without agitation nor refrigeration.
5.5.1.2.5 Freezing of the milk
Ice shall not form in the milk under the milk surface during either cooling or storage when the tank is used in
ambient temperature between + 5 °C and the PT and is filled with milk to:
a) for two milking tanks: between 20 % and 100 % of its rated volume;
b) for four milking tanks: between 10 % and 100 % of its rated volume;
c) for six milking tanks: between 6,7 % and 100 % of its rated volume.
5.5.1.2.6 Agitation of the milk
Operating of the agitator shall not cause milk to overflow when the tank contains any volume of milk up to 100 % of
its rated volume.
The agitator shall be capable of producing a uniform distribution of the fat throughout the milk, so that the fat
content of samples, randomly selected from the tank, does not differ by more than 0,1 g of fat per 100 g of milk.
This requirement shall be achieved by operating the agitator for not more than 2 min, when the tank contains any
volume of milk between 10 % and 100 % of its rated volume at + 4 °C and after allowing to stand unagitated for 1 h.
For tanks utilising a continuous agitation system, this requirement shall be achieved by operating the agitator for
not more than 10 min.
These requirements shall be achieved without the formation of froth or butter.
The milk used for these agitation tests shall be bulk raw whole milk with fat content of 4 g ± 0,5 g per 100 g of milk
at a temperature of + 4 °C – 1 °C.
5.5.1.2.7 Safe operating temperature
The tank shall be able to cool any milking as detailed in 5.5.1.2.2, under automatic control, when the equipment is
operated at the specified SOT.
The cooling time of the first milking shall not exceed the specified cooling time as given in Table 2 by more than
25 %.
5.5.2 Prevention of milk contamination
5.5.2.1 General
Materials in contact with cleaning water and chemicals shall be resistant to cleaning and disinfecting agents in
normal conditions of dosage and temperature so that they shall not impart a taint to milk.
Materials for seals shall be fat-resistant and non-toxic. These materials shall comply with the requirements of the
EN 1672-2:1997.
5.5.2.2 Inner vessel
Any bridge or bracket required to be supported from the inner vessel shall be welded to it, shall be provided with
upturned edges not less than 10 mm high and shall be sloped to drain away from the inner vessel.
All joints shall be welded and shall have a surface finish, strength and corrosion resistance not less as specified in
hereafter.
Inner vessel and all attachments which are in, or may come into contact with milk shall:
 be manufactured from austenitic stainless steel or from a material complying with European or national
specifications;
 have a surface roughness R £ 1 μm where R is as defined by EN ISO 4287:1998;
a a
 use a grade of steel the quality of which shall be at least equivalent to that of stainless steel X5 Cr Ni 18-10
1.4301, as defined in EN 10088-2:1995, especially with regard to suitability for welding and resistance to
corrosion.
All inside corners of the inner vessel which form an angle of less than 2,36 rad (135°) shall have radii R not less
than 25 mm (see Figure 1). All other corners in the inner vessel shall have radii not less than 3 mm.
Key
R  Radius
Figure 1 - Inner vessel
Every component which is permanently attached within the inner vessel shall be welded to it. The welds shall have
radii not less than 3 mm and the angles shall be not less than 1,57 rad (90°). All components which are not
practical to be welded to the inner vessel shall be fastened so that they can be easily removed for cleaning.
5.5.2.3 Openings and lids in connection with the inner vessel
a) The tank shall be provided with at least one opening for inspection having dimensions of at least equivalent to
an ellipse of 300 mm · 400 mm. Each opening shall have upturned edges not less than 10 mm high;
b) Each opening shall be provided with a lid which overlaps the opening and has adequate down turned edges to
protect the milk from contamination;
c) Openings and lids shall permit easy and safe inspection of all internal parts of the inner vessel, the milk and
also sampling of the milk;
d) On tanks to be cleaned manually the openings and lids shall be so constructed that all internal parts of the
inner vessel can be cleaned easily and safely by hand from outside the tank;
e) Openings and lids shall have all inside corners constructed to provide internal radii of not less than 3 mm;
f) Any aperture in a lid, or a bridge which forms part of a tank lid assembly, shall also be provided with a cover.
All apertures and covers shall comply with above requirements with regard to upturns, downturns and radii;
g) Lids and covers over openings and apertures shall provide the inner vessel with a degree of protection against
the ingress of foreign solid parts and water not less than IP 43 as detailed in EN 60529:1991.
5.5.2.4 Thermometers
Glass thermometers and thermometers with mercury shall not be used.
5.5.2.5 Agitators
The agitation device shall be so designed and constructed that:
a) shaft seals shall be provided against any contamination of the milk which can enter the inner vessel from
outside;
b) material and surface roughness shall comply with 5.5.2.2;
c) corners shall have angles not less than 1,57 rad (90°), welds and corners shall have a radii not less than
3 mm;
d) the lowest point at which milk could enter a coupling on an agitator shall be at least 30 mm above the level of
milk which corresponds to maximum volume.
5.5.2.6 Cleaning
The inner vessel shall be designed to be cleanable as defined in 3.5.1 of EN 1672-2:1997.
Tanks having a manhole(s) as the only access to the inner vessel, shall be fitted with an automatic cleaning
equipment complying with annex C.
5.6 Ergonomics
Lids shall be so designed and constructed that during the opening and closing operations the ergonomic
requirements of EN 1005-3:2002 are fully met.
The height of the rim of the tank above the floor or a permanent working platform shall be not more than 1,35 m at
any access point when the tank is installed in its reference position.
When this is achieved by means of ladder and platform assemblies fixed to the tank, these ladders and platforms
shall comply with the following requirements:
 the platform dimensions shall be at least 300 mm wide and 250 mm deep;
 the distance from floor to the first step shall be max. 450 mm;
 the distance from the platform to the rim at the biggest opening of the tank shall be not less than 1 m.
5.7 Unexpected start-up
As the tank is provided to operate under automatic control, the hazard due to unexpected start-up exists only
during maintenance operations. Then it shall be able to be safely disconnected from electrical supply (see 5.2.2.3).
If the electrical disconnecting device is not visible from the maintenance operating points, it shall be lockable.
If the lockable disconnecting device is not a part of the tank, information shall be given in the instruction handbook
(see 7.4).
NOTE see 5.2.2.3. The same protective measure can be used for both requirements.
5.8 Other general requirements for tanks
5.8.1 Temperature resistance
The tank and associated equipment shall be designed and constructed to withstand the following temperatures:
operation from + 5 °C to SOT
storage and transport from - 25 °C to + 55 °C
cleaning water up to + 90 °C for 2 min
up to + 70 °C continuously
5.8.2 Inner vessel
The inner vessel shall be so designed that the rated volume (V) is between 90 % and 98 % of the maximum
r
volume (V ).
m
5.8.3 Outer casing
The outer casing shall be rigid, shall prevent the ingress of water and foreign matter and shall be self draining of
surface water.
5.8.4 Thermal insulation
The insulating material shall be non-settling and shall not be liable to displacement during storage, transportation or
operation.
Adequate provision shall be taken to ensure that the thermal insulation will comply permanently with the
requirements of 5.5.1.2.4.
5.8.5 Supports and feet
A tank shall be fitted with adjustable supports or feet to permit it to be placed in its reference position when installed
on a floor with a gradient not greater than 1 in 50 in any direction so long as the fall of the floor between the outer
supports is not greater than 50 mm.
The distance between the tank and the floor (with the exception of the supports or feet) when installed on a
horizontal floor shall be not less than 100 mm.
5.8.6 Milk inlet aperture
The tank shall be provided with at least one milk inlet aperture.
All milk inlet apertures shall have a diameter of not less than 40 mm, and not more than 210 mm.
NOTE Milk should enter the tank without turbulence and without forming froth.
5.8.7 Outlet
The tank shall be provided with an outlet.
The outlet orifice and the bottom of the inner vessel shall be designed so that all the contents drain to the outlet.
With the tank in its reference position and containing 40 l of test water, at least 39,8 l shall run out in 1 min by
gravity.
The highest point of the inside of the outer end of the outlet pipe, including the outlet valve, shall be lower than an
imaginary line continued from the line of the inner vessel (see example in Figure 2).
Key
1 Horizontal
2 Line which represents the level of the vessel
Figure 2 — Example of outlet pipe
The outlet pipe shall be constructed from stainless steel and shall have an inner diameter of at least 48 mm. The
outlet pipe shall have not more than one bend and one detachable hygienic joint, or if an outlet valve is fitted 2
detachable hygienic joints. The outlet valve or, if there is no valve, the outlet pipe, shall terminate with a male
thread fitt
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