GB/T 12753-2020Steel wire ropes for conveyer belts (English PDF)

Foreword

This Standard was drafted in accordance with the rules given in GB/T 1.1-2009. This Standard replaces GB/T 12753-2008 "Steel wire ropes for conveyer belts". Compared with GB/T 12753-2008, in addition to editorial modifications, the main technical changes in this Standard are as follows: - modified the provisions on wire rod; added the provisions on technology agreement (see

5.1.1 of this Edition,

7.1.1 of Edition 2008); - added the provisions on zinc ingot material (see

5.1.2 of this Edition); - modified "steel wire in wire rope" to "stranded steel wire" (see

5.2 of this Edition,

7.1 of Edition 2008); - modified the provisions on the allowable deviation and out-of-roundness of stranded steel wire (see

5.2.1 of this Edition,

6.1 of Edition 2008); - added and adjusted the level of steel wire ropes; modified to level I, level II, level III and level IV (see

5.2.2 of this Edition,

5.2 of Edition 2008); - adjusted the nominal tensile strength of steel wire to 2260MPa, 2360MPa, 2460MPa and 2560MPa (see

5.2.2 of this Edition,

7.1.2 of Edition 2008); - deleted level H of zinc layer weight; changed the symbol of the minimum zinc layer heavyweight to 30delta as level M, 60delta as level N (see

5.2.5 of this Edition,

5.3 of Edition 2008); - modified the requirements for appearance quality (see 5.2.6,

1 Scope

GB/T 12753-2020 is the Chinese national standard on steel wire ropes for conveyer belts, in the field of metallurgy. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 21 July 2020 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 February 2021. Classification: ICS 77.140.65, CCS H49. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This Standard specifies order content, requirements, test methods, inspection rules, packaging, quality guarantee period, transportation, storage, marks and quality certificate of steel wire ropes for conveyer belts. This Standard is applicable to galvanized steel wire ropes for steel wire rope core conveyor belt skeleton reinforcement material (hereinafter referred to as "steel wire ropes".

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 228.1, Metallic materials - Tensile testing - Part 1: Method of test at room temperature

GB/T 239.1, Metallic materials - Wire - Part 1: Simple torsion test GB/T 470, Zinc ingots

GB/T 1839, Test method for gravimetric determination of mass per unit area of galvanized coatings steel products

GB/T 2104, Steel wire ropes - Packing, marking and certificate - General requirements

GB/T 8358, Steel wire ropes - Determination of measured breaking force

GB/T 8706, Steel wire ropes - Vocabulary, designation and classification

GB/T 24242.2, Non-alloy steel wire rod for conversion to wire - Part 2: Specific requirements for general purpose wire rod YB/T 081, Rule for rounding off of numerical values and judgement of testing values for technical standards of metallurgy The surface of steel wire rope shall be free of oil, water, dirt and other impurities.

5.3.2 Steel wire connector Single-strand connectors are not allowed in the steel wire rope. The steel wire connectors shall also be minimized. When steel wires have to be connected during twisting, steel wires with a nominal diameter of less than 0.40mm shall have plug-in connectors; steel wires with a nominal diameter greater than or equal to 0.40mm may use butt welding connectors or plug-in connectors. The plugged wire ends shall be sealed inside the strands. They shall not be exposed. The wire at the splice is allowed to have partial crossing. The distance between steel wire connectors in the same steel wire strand shall be greater than 100m.

5.3.3 Pre-deformation Steel wire ropes shall be pre-deformed, without looseness, with small residual torsion, and no spring loops, waves, hard bends and other defects.

5.3.4 Structure The steel wire rope shall be an open structure. According to its structure, it is divided into three types: 6×7-WSC, 6×19-WSC and 6×19W-WSC, as shown in Annex A. After negotiation between the supplier and the purchaser, steel wire ropes of other structures can also be supplied.

5.3.5 Level of steel wire ropes The steel wire ropes are divided into level I, level II, level III and level IV, as shown in Table 2.

5.3.6 Twisting direction and type of steel wire ropes Steel wire ropes are divided into right twist (Z) and left twist (S) according to the twist direction. In general, the left twist and right twist shall be half and half at the time of delivery. It can also be adjusted according to user order requirements. The twisting method of steel wire rope is alternating twist.

5.4 Marks and classification of steel wire ropes The marks and classification of steel wire ropes shall meet the requirements of GB/T 8706.

5 Requirements...

6 Test methods...

7 Inspection rules...