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2012_OL1_1.7_U

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LEEA -L2
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  1 © Lifting Equipment Engineers Association 2012 – Unit 1.7 UNIT 1.7 - VERIFICATION OF LIFTING EQUIPMENT (TESTING AND EXAMINATION) Contents Introduction 1. Preparing for an examination 2. Conducting an examination 2.1 Chain slings 2.2 Hooks 2.3 Shackles 2.4 Eyebolts 2.5 Wire ropes 2.6 Fabricated items 2.7 Lifting machines 2.8 Marking or re-marking 3. Test and examination equipment 3.1 Test machines and force/load measuring equipment 3.2 Dimensional measuring equipment 3.3 Non-destructive test equipment 4. Types of test and what they might tell us 4.1 Dimensional verification 4.2 Operational test 4.3 Light load test 4.4 SWL and deflection measurement 4.5 Proof load test 4.6 Breaking load test/minimum breaking load test 4.7 Hardness test 4.8 Liquid penetration crack detection 4.9 Magnetic particle crack detection 4.10 Radiography (X-ray) crack detection 4.11 Eddy current crack detection 4.12 Ultrasonic crack detection 4.13 Electromagnetic wire rope examination 5. Actions following an examination  2 © Lifting Equipment Engineers Association 2012 – Unit 1.7 Introduction  All lifting equipment must be verified: (a) to ensure it is safe before first use, and (b) periodically once it is in service to ensure it remains safe to use. Until the end of the twentieth century, all of the various UK regulations, and therefore the standards, called for lifting equipment to be proof load tested and examined to ensure this was the case. This was irrespective of the logic or need for such a test. Users were then required to retain the ‘test certificate and examination reports’. Modern legislation, standards and codes of practice take a more sensible approach. For certain products, proof load testing remains valid. However, for many common items, this is not the case and other tests are more meaningful. Standards give the verification methods for new products, although it is no longer necessary for the user to be given the results. For in-service equipment, LOLER places the duty for deciding if, and what, tests are necessary on the ‘competent person’ making a thorough examination. It requires the details of any tests made to be included on the examination report. Note the words ‘any test’. The report needs to include any functional, light load, non-destructive tests etc, not just a proof load test. This unit considers the thorough examination, the general requirements for test equipment used in the examination, and the tests available to the examiner.  As noted in unit 1.1, LOLER does not use the word ‘test’ but instead refers to a ‘thorough examination’. The purpose of the examination is to determine if the item being examined is safe to use or otherwise. For many items, the examination will be limited to a full visual examination. For others it will need to be supplemented by any one of a number of tests if the correct conclusion is to be reached.  3 © Lifting Equipment Engineers Association 2012 – Unit 1.7 1. Preparing for an examination In all but a few cases, lifting accessories and manually operated machines will be readily accessible for examination. In contrast, for a runway or crane, the examination must be made in situ and special procedures are necessary. Study is therefore confined to the more basic types of examination that can be made at the bench or, in some cases, on the floor. However, the general principles are the same for all examinations. The area in which the examination is to be made must be clean and clear of any debris that may hinder the examination or harm the item under examination. It must be well lit, either by natural or artificial light, and free from shadows or tinting, which may impede the visual detection of faults. If it is necessary to suspend an item (e.g. chain block), the suspension point should be at the correct height to allow relevant parts to be examined easily. In some cases, additional lighting such as a pencil torch or lead light may be necessary. This is particularly the case with suspended machines. Most examinations are made by the naked eye. However, for some items, the use of a magnifying glass, dental mirror or similar visual aid may be necessary. The item(s) under examination must be clean and free from rust, grease, paint etc, which might obscure defects. Where items require cleaning, an appropriate method should be used which will not harm the item. In the case of composite items (for example, a spreader with top and bottom slings shackled to the beam) and machines, these should be stripped down as may be necessary for the examination, prior to cleaning. The parts must be clearly identified and kept together. Examples of cleaning methods: ã  Brushing or wire brushing to remove light rust and debris. ã  The use of proprietary solutions to remove stronger rust penetrations. Great care must be exercised here. Many of these products are acid-based and, whilst dilute acid preparation may be used on some items of lifting gear, this is not generally the case. In particular, alloy steels are prone to hydrogen embrittlement when they have been in contact with acid or caustic conditions. ã  Shot blasting or rumbling to remove scale. ã  Degreasing to remove oils and fats.  Although it is not part of the competent person’s duty to strip down and rebuild equipment, in practice the examiner may find it is necessary to do this to some extent. Much will depend on the employer, or the conditions that prevail on the site where the examination is being undertaken. The requirements will also vary with the complexity of the item(s) under examination. As part of the preparation, the examiner should ensure that all the necessary tools are to hand. Dimensional checks form part of any examination. The examiner should therefore also have all the appropriate measuring instruments (e.g. rule, micrometer etc) and gauges for the items under examination. For reference purposes, copies of the relevant British or other Standards, drawings or work specifications should be  4 © Lifting Equipment Engineers Association 2012 – Unit 1.7 available. Finally, the examiner should have the necessary stamps or other appropriate marking devices to mark, or re-mark, the item with its distinguishing number, SWL and any other necessary information. 2. Conducting an examination The examination should start with correct identification of the item. In the case of a newly manufactured item, where the examination is made following the initial test, the details should be checked against the test record. In the case of an item that has been in service, if there is any doubt as to its identity and/or history, the previous examination reports and maintenance records should be checked as appropriate. Remember that LOLER leaves it to the discretion of the competent person in deciding if a test is necessary and, if so, the nature and form of any such test, in reaching a conclusion as to whether or not the item is safe. The onus as to whether or not the equipment may enter, or return to service is on the user, not the examiner. The duty of the competent person is only to determine if the equipment is safe to use or not - and to report the fact. The examination must be conducted systematically to ensure all parts are thoroughly examined. In the case of slings or long lengths of chain, rope or wire rope, the examination should start at one end and proceed along the length ensuring all parts are observed. For example, remember to turn a chain fully – it has four sides not two. If the examination is interrupted, it should be started again from the beginning to ensure no part is missed. It is important to remember that the permissible amounts of wear, elongation, broken wires etc given in this course, standards, manufacturer’s instructions and similar sources are maximums . A judgement has to be made as to whether the item is fit to continue for a period of service – that is, it will be safe to operate until the next examination is due - in the prevailing service conditions. Carry out dimensional checks against the standard, specification or drawing. Carry out any other checks necessary to ensure the item is in compliance with the standard and/or specification. Carry out a full visual examination. Below are some examples of some typical items and a list of the points to be considered during their examination following a period of service. In later units, when specific items are discussed, these matters are considered in greater detail. 2.1 Chain Slings Examine and check for: 1. Sizes of chain, links and hooks for loads required. 2. Stretch due to wear and loading (5% maximum), variation in the lengths of the legs; (compare with past records). 3. Hooks for openings and distortion (see below). 4. Links and rings for distortion or roundness. 5. Chain for bent and twisted links. The links should articulate freely. 6. All parts for wear, (8% reduction in diameter), corrosion, nicks and chemical attack. 7. Cracks, weld faults and marks in weld areas.
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