bsen818-4-1997起重用短扁节链条安全性第4部分8质量等级止档链

bsen818-4-1997起重用短扁节链条安全性第4部分8质量等级止档链内容摘要：

grade of sling For the purpose of designation in accordance with annex C, the same as the grade of the short link chain used in the manufacture of the sling, . 8. master link A link forming the upper terminal of a chain by means of which the sling is attached to the hook of a crane of other lifting machine (see figures 1 to 4). length of a leg For a finished sling, the length from the lower bearing point of the lower terminal to the upper bearing point of the upper terminal (see figures 1 to 4 as examples). intermedi ate master link A link used to connect one or two legs of a sling to a master link. lower terminal A link, hook or other device fitted at the end of a leg of a sling, remote from the master link or upper terminal. mechanical joining device A means of connection which does not depend on welding. It may be integral with a ponent or a separate ponent (see figure 5). joining link A welded link fitted to the end of a chain to connect it either directly or through an intermediate link to an upper or lower terminal or intermediate master link, or in the case of an endless sling to the other end of the chain (see figures 1 to 4). intermediate link A welded link used to form a connection between the terminal and the joining link fitted to the chain (see figures 1 to 4). manufacturing proof force (MPF) of a chain sling A force applied during manufacture as a test to the whole sling or a force applied as a test to a section of a sling. working load limit (WLL) of a chain sling The maximum mass which a sling is authorized to sustain in general lifting service. petent person A designated person, suitably trained (see of EN ISO 9001 : 1994) qualified by knowledge and practical experience, and with the necessary instructions to enable the required tests and examination to be carried out. 4 Hazards The release of a load due to failure of lifting accessories such as slings or their ponent parts puts at risk either directly or indirectly the life or health of those persons within the danger zone of lifting equipment. In order to provide the necessary strength and durability of lifting accessories, this Part of EN 818 lays down requirements for the design, selection of materials of construction and testing to ensure that specified levels of performance are met. Fatigue failure has not been identified as a hazard when chain slings having the specified levels of performance given in this Part of EN 818 are used in general lifting service. Since failure can be caused by the incorrect choice of grade and specification of lifting accessory this Part of EN 818 also gives the requirements for marking and the manufacturer39。 s certificate. Errors in fitting together of assemblies can also lead to premature failure and this Part of EN 818 contains dimensional requirements to allow correct fit. Those aspects of safe use associated with good practice are given in prEN 8186. Table 1 contains all the hazards which require action to reduce risk, identified by risk assessment as being specific and significant for chain slings grade 8. 5 Safety requirements Components of a chain sling Chain The chain shall ply with prEN 8182. Fed steel ponents Fed steel ponents, including mechanical joining devices, for use with grade 8 chain in the manufacture of chain slings shall conform to prEN 16771. Table 1. Hazards and associated requirements Hazards identified in annex A of prEN 1050 Relevan t clause of annex A of EN 2922 : 1991/A1 : 1995 Relevant clause/s ubclaus e of this Part of EN 818 Mechanical hazard due to inadequacy of strength 5 6 7 8 15 Errors of fitting hazard Page 5 EN 8184 : 1996 Links Master links and intermediate master links shall ply with prEN 16774. Lower terminal links shall ply with prEN 16774 except for those clauses relating to link dimensions. Joining links and intermediate links shall conform with prEN 16774 except for those clauses related to link dimensions. Lower terminal links, joining links and intermediate links shall satisfy the appropriate requirements of . Hooks Fed steel lifting hooks with latch shall ply with prEN 16772. Hooks not covered by these standards shall ply with . NOTE. The details of fed steel selflocking hooks are contained in prEN 16773, which is in the course of preparation. Design and construction Slings assembled with mechanical joining devices The assembly of the sling shall be undertaken in accordance with the chain manufacturer39。 s instructions. Slings shall be so designed and manufactured that when assembled in accordance with the manufacturer39。 s instructions, the unintentional disconnection of any ponent part cannot occur. Pearshaped links shall only be used if they have an integral joining device. Assembled mechanical joining devices shall have a working load limit not less than that of the chain(s) to which they are connected in a chain sling. The ponent parts of the chain sling shall ply with the requirements of except in respect of joining and intermediate links. Slings assembled by welding Pearshaped links shall not be used as terminals. Joining links and intermediate links shall have a working load limit not less than that of the chain(s) to which they are connected in a chain sling. The dimensions of joining links and intermediate links shall be such as to ensure adequate articulation with parts of the chain sling which they connect. The ponent parts of the sling shall ply with the requirements of . Endless slings The manufacture of an endless sling shall be either by the。