1、March 2015DEUTSCHE NORM English price group 9No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 27.060.30!%LRb“2414763
2、www.din.deDIN 4754-3Heat transfer installations working with organic heat transfer fluids Part 3: Level controller,English translation of DIN 4754-3:2015-03Wrmebertragungsanlagen mit organischen Wrmetrgern Teil 3: Fllstandsicherungen,Englische bersetzung von DIN 4754-3:2015-03Installations de transf
3、ert de chaleur aux fluides caloporteurs organiques Partie 3: Dispositifs antidbordement,Traduction anglaise de DIN 4754-3:2015-03SupersedesDIN 32728:198102, withdrawn 200709See start of applicationwww.beuth.deDocument comprises 15 pagesDDIN-Normenausschuss Heiz- und Raumlufttechnik sowie deren Siche
4、rheit (NHRS)DIN-Sprachendienst10.16DIN 4754-3:2015-03 2 A comma is used as the decimal marker. Start of application The start of application of this standard is 2015-03-01. For DIN 32728:1981-02 there is no transition period as the standard was withdrawn in 2007-09. DIN 4754-3:2015-03 3 Contents Pag
5、e Foreword 4 Introduction 5 1 Scope . 6 2 Normative references . 6 3 Terms and definitions . 6 4 Safety requirements 7 4.1 Materials, design . 7 4.2 Leak-tightness . 7 4.3 Measuring elements 7 4.4 Measuring vessels 8 4.5 Evaluation units 8 4.6 Measured value transmission . 10 4.7 Function test 11 4.
6、8 Other devices 11 5 Testing . 11 5.1 Test objects and test documents 11 5.2 Test medium 12 5.3 Inspecting the design and test documents . 12 5.4 Testing the leak-tightness 12 5.5 Testing the measured value transmission . 12 5.6 Testing the switching points . 12 6 Marking . 13 Annex A (informative)
7、Test types 14 Bibliography . 15 DIN 4754-3:2015-03 4 Foreword This standard includes safety requirements in Clause 4. This document has been prepared by DIN-Normenausschuss Heiz- und Raumlufttechnik (DIN Standards Committee for Heating and Ventilation), Working Committee NA 041-01-41 AA Wrmebertragu
8、ngsanlagen. DIN 4754, Heat transfer installations working with organic heat transfer fluids consists of the following parts: Part 1: Safety requirements, test Part 2: Draught diverter Part 3: Level controller Attention is drawn to the possibility that some of the elements of this document may be the
9、 subject of patent rights. DIN shall not be held responsible for identifying any or all such patent rights. In addition to the legal units of measurement, this standard also uses the unit “bar”. It should, however, be noted that according to the German law on units in metrology, the use of these uni
10、ts is not permitted in official or business communications within Germany. Conversion: Unit not permitted Unit permitted Conversion bar Pa 1 bar = 105Pa Amendments This standard differs from DIN 32728:1981-02 (withdrawn 2007-09) as follows: a) Subclauses 1.2 and 1.3 have been deleted; b) Subclause 4
11、.7 has been deleted; c) Subclause 5.2 “Test types” has been moved to informative Annex A; d) the standard has been editorially revised. Previous versions DIN 32728: 1981-02 DIN 4754-3:2015-03 5 Introduction The purpose of this standard is to determine certain fundamental requirements with respect to
12、 the technical design and testing of level controllers in heat transfer installations working with organic heat transfer fluids. The tests and test methods described in this standard may also be applied to type and acceptance tests if required. The revision of DIN 4754:1994-09 also made a revision o
13、f DIN 32727:1981-02 necessary. This revision process incorporated knowledge and experience concerning draught diverters with the state of the art and also took current legal provisions into consideration. DIN 4754-3:2015-03 6 1 Scope This standard applies to level controllers in heat transfer instal
14、lations working with organic heat transfer fluids according to DIN 4754-1 and specifies minimum requirements in respect to the technical desing and testing of level controllers. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are i
15、ndispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. DIN 4754-1:2015-03, Heat transfer installations working with organic heat transfer fluids Part 1: Safety r
16、equirements, test E DIN EN 50156-1 (VDE 0116-1):2013-05, Electrical equipment for furnaces and ancillary equipment Part 1: Requirements for application design and installation DIN EN 61010-1 (VDE 0411-1):2011-07, Safety requirements for electrical equipment for measurement, control and laboratory us
17、e Part 1: General requirements DIN EN 60529 (VDE 0470-1), Degrees of protection provided by enclosures (IP-Code) 3 Terms and definitions For the purposes of this document, the terms and definitions given in DIN 4754-1:2015-03 and the following apply. 3.1 level controller device that automatically sw
18、itches off and locks the heating if the lowest permissible filling level is not maintained in the heat transfer installation Note 1 to entry: It may contain and/or actuate signal devices. Note 2 to entry: In the following, level controllers are also referred to as “devices”. 3.2 internal level contr
19、oller level controller where the measuring element is located within the heat transfer installation 3.3 external level controller level controller in which the measuring element is located in a separate measuring vessel, which is connected to the heat transfer installation via connecting pipes that
20、are capable or incapable of being shut off 3.4 measuring element part of the level controller that generates a measured value equivalent to the filling level 3.5 measured value transmission device that transfers the measured value to the evaluation unit DIN 4754-3:2015-03 7 3.6 evaluation unit assem
21、bly that converts the measured value corresponding to the volume flow rate generated by the measuring element into an electrical output signal 3.7 switching point fluid level at which the heating is required to be switched off 4 Safety requirements 4.1 Materials, design The quality of the materials
22、and the form and design of the components shall ensure that the level controller is permanently safe and operational for a reasonable period when correctly installed and used under the conditions indicated by the manufacturer for operation, maintenance and adjustment and the associated mechanical, c
23、hemical and thermal loads. The parts of the measuring element through which the heat transfer fluid flows during operation, including the associated enclosure, shall be in accordance with the material requirements of DIN 4754-1 and shall be designed for at least PN 16. Materials that cause chemical
24、reactions with the heat transfer fluid shall not be used. If metal bellows or a similar component are used as a sealing element, this is permissible if a signal shift to the safe side occurs if the element breaks. Hermetically-sealing moving parts (e.g. metal bellows or similar components) shall be
25、calculated and designed for a minimum of 10 000 work cycles with the greatest range of motion. Testing shall be according to 5.3. 4.2 Leak-tightness 4.2.1 The enclosure and the sealing parts shall be leak-tight outwards so that, at most, an oil film results on the outer surface which does not cause
26、any drop formation within 24 h under the allowable pressure and temperature loads nor when cold. Testing shall be according to 5.4. 4.2.2 The level controllers shall not exhibit any openings that can form a direct connection between the atmosphere and heat transfer fluid. The aeration and ventilatio
27、n of the external measuring vessels shall be via the installation system. Testing shall be according to 5.3. 4.3 Measuring elements 4.3.1 Mechanical measuring elements Any mechanically moving or guided parts shall be prevented from jamming. If the measuring element consists of immersion bodies (floa
28、ters or displacers), these shall be adequately guided so as to prevent jamming. If the immersion body is led via the enclosure or a tube, there shall be a DIN 4754-3:2015-03 8 free movement allowance of at least 5 mm on all sides between the immersion body and guide (i.e. diameter free movement allo
29、wance 10 mm). The immersion body shall move far enough downwards to ensure that it moves over the switching point. Constructive measures shall be implemented to ensure that the immersion body cannot slide out of its guide. Testing shall be according to 5.5.1 and 5.6. 4.3.2 Non-mechanical measuring e
30、lements In the case of non-metallic measuring elements, it shall be ensured that deposits from the heat transfer fluid on the measuring element do not impair its function or cause the heating to shut down. Testing shall be according to 5.5.2 and 5.5.3. 4.4 Measuring vessels 4.4.1 Internal measuring
31、vessels Internal measuring vessels or internal immersion body guides shall be designed to enable unimpeded communication. Openings for replenishing the filling level shall have a diameter of at least 20 mm. The openings shall be located both at the lowest point as well as at the upper end of the mea
32、suring vessel. Testing shall be according to 5.1.2 and 5.3. 4.4.2 External measuring vessels 4.4.2.1 The connecting pipes for replenishing the filling level shall be located at the top and bottom of the measuring vessel and have a corresponding clear diameter of minimum 20 mm. Testing shall be accor
33、ding to 5.1.2 and 5.3. 4.4.2.2 Shut-off devices in the connecting pipes that are to be assigned to the measuring vessels shall have a nominal size of at least DN 20 at their narrowest point and may only permit operation of the heat transfer installation in a completely opened position. Testing shall
34、 be according to 5.1.2 and 5.3. 4.5 Evaluation units 4.5.1 Electrical components Electrical components are subject to the requirements according to DIN EN 61010-1 (VDE 0411-1); the fault exclusions according to E DIN EN 50156-1 (VDE 0116-1):2013-05, 10.5.5.3.1 to 10.5.5.3.6 have overriding applicati
35、on. Safety-relevant requirements for electrical devices are specified in Table 1 as references to clauses of DIN EN 61010-1 (VDE 0411-1):2011-07 for devices that are only used in industrial applications. DIN 4754-3:2015-03 9 Table 1 Safety-relevant requirements for electrical devices Requirement Ref
36、erence to clauses of DIN EN 61010 (VDE 0411-1):2011-07 for devices that are only used in industrial applications Protection against electric shock 6 Protective earth connection 6 Terminals and connections 6.10 Setup 6.9 Resistance to moisture and dust 11.6 Dielectric strength and insulation resistan
37、ce 6.8 Heating 10 Environmental loads 10.5 Mechanical strength 8 Threaded parts and joints - Creepage distances and air gaps, insulation gaps 6.7 Heat and fire resistance, tracking resistance 9, 10 Individual parts 14 Improper use 6.5 The following electrical circuits shall not impair the function o
38、f the level controllers. The evaluation unit shall satisfy at least degree of protection IP 44 according to DIN EN 60529 (VDE 0470-1) and withstand the resulting 70 C ambient temperature and the allowable working temperature TBin the enclosure of the evaluation unit. The mechanical parts of the swit
39、ching elements shall be mounted with low-friction bearings. The evaluation unit shall exhibit contacts with transient characteristics. Mercury switching tubes, Reed relays and Reed contacts are not permissible. Testing shall be according to 5.5.2. 4.5.2 Adjustment of switching points It shall only b
40、e possible to adjust the switching points using tools. The fluid level shall not fall below the fluid level at the set switching point during any operating condition of the device. Testing shall be according to 5.6. DIN 4754-3:2015-03 10 4.5.3 Locking and unlocking device The level controller shall
41、be equipped with a locking device. It can be either mounted on the device itself or embedded in the downstream electric circuit. If locking occurs in the downstream circuit or unlocking occurs by remote means, the location and type of fault shall be displayed. Remote unlocking is permissible if the
42、level controller specified according to DIN 4754-1:2015-03 can be viewed from the unlocking point. Testing shall be according to 5.6. 4.6 Measured value transmission 4.6.1 Mechanical transmission The mechanical transmission shall work with as little friction as possible. Devices with a manually read
43、justable stuffing box do not fulfil this requirement. Moving bushings and sealing elements shall be calculated and designed for at least 5 000 work cycles at the greatest measured value difference, (e.g. stroke) maximum allowable working pressure pBand maximum allowable working temperature TB. The f
44、unctional sequence shall be designed to ensure safety if the transmission elements fail. It shall not be possible to block the transmission elements and rotary point bearings shall not be prone to faults. Testing shall be according to 5.5.1. 4.6.2 Electric and photoelectric transmission The transmis
45、sion shall be such that a drop below the switching point is simulated both upon failure of the measuring signal as well as in the event of a short-circuit or an interruption in the evaluation unit. The evaluation unit shall be protected against the effects of electrical extraneous fields and against
46、 light effects from outside that can simulate a measuring signal. Testing shall be according to 5.5.2. 4.6.3 Magnetic transmission The magnetic transmission shall be such that a field strength diminution at the magnet of the evaluation unit and/or the measuring element results in an automatic signal
47、 shift in the direction of the lower limit filling level. If this is not the case, both the magnetic materials and the installation conditions shall be selected with respect to the ambient temperature influences so that the minimum field strength does not drop below the field strength required for t
48、he interaction of all components of the magnetic transmission unit over longer time periods. This is to be expected if the field strength is not reduced by more than 3 % over a duration of 10 years. Appropriate verification shall be provided. The measured value transmission shall be protected agains
49、t deposits, in particular those of magnetizable parts from the heat transfer fluid. The magnets shall also be protected against the effect of extraneous fields. The magnetic switches shall be mounted at the required distances. Testing shall be according to 5.3 and 5.5.3. The associated mechanical transmission parts shall be tested according to 5.5.1. 4.6.4 Sound and ultrasound transmission The response time until the signal is triggered shall be shorter than 10 s; the requirements of Clause 4 apply by analogy. Testing shall be according to 5.3 and 5.4. D
