GB/T 12753-2020 (GB/T12753-2020, GBT 12753-2020, GBT12753-2020) & related versions
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GB/T 12753-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.65
H 49
Replacing GB/T 12753-2008
Steel wire ropes for conveyer belts
ISSUED ON: JULY 21, 2020
IMPLEMENTED ON: FEBRUARY 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 6
4 Order content ... 6
5 Requirements ... 6
6 Test methods ... 10
7 Inspection rules ... 12
8 Packaging, quality guarantee period, transportation, storage, marks and
quality certificate ... 13
Annex A (normative) Minimum breaking force of steel wire rope structure, size
and level ... 15
Annex B (informative) Spool for winding steel wire rope for conveyor belt ... 18
Bibliography ... 19
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 30δ as level M, 60δ 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, 5.3.1 of this
Edition, 7.1.6, 7.2.3 of Edition 2008);
- deleted the provisions on diameter increase of center steel wire (see 7.2.1.2
of Edition 2008);
- modified the requirements for steel wire connector; specified that steel
wires with a nominal diameter less than 0.40mm shall use plug-in
connector, steel wires with a nominal diameter greater than or equal to
0.40mm may use butt welding connector or plug-in connector (see 5.3.2
of this Edition, 7.2.1.3 of Edition 2008);
- adjusted and added nominal diameter of steel wire ropes; changed 6×19-
WSC range to 6.0mm~15.0mm, 6×19W-WSC range to 6.0mm~15.0mm;
added some intermediate specifications (see 5.5.1, Annex A of this Edition,
6.3 of Edition 2008);
- modified the minimum breaking force and reference weight of steel wire
Steel wire ropes for conveyer belts
1 Scope
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.
5.5 Size of steel wire ropes
5.5.1 Diameter
The nominal diameter D and allowable deviation of steel wire ropes shall
twist speed during the arbitration test is 1r/s.
6.1.4 The knotted tensile test is carried out in accordance with the provisions of
GB/T 228.1.
6.1.5 The zinc layer weight test shall be carried out according to the provisions
of GB/T 1839.
6.1.6 Use hand feeling and visual inspection to check the appearance quality.
6.2 Tests of steel wire ropes
6.2.1 Use hand feeling and visual inspection to check the appearance quality
of steel wire ropes.
6.2.2 Untie the two opposite strands at either end of the steel wire rope, about
two lay lengths. When the two strands are restored to their original positions
and all constraints are lifted, the steel wires and strands in the steel wire rope
remain in their original positions. When they do not unravel on their own, the
steel wire ropes are not loose.
6.2.3 After removing the rope end by 1m~2m, bend into an angle of about 90°
at about 50mm from the rope end. Pinch this elbow tightly to avoid the steel
wire rope spinning when pulling out a 6m long sample (not cut from the coil).
Then, release the free section of the steel wire rope. Let it spin freely without
tension. The number of rotations shall not exceed 3 revolutions (r), which
means that the residual torsion of the wire rope is small.
6.2.4 The diameter of the steel wire rope shall be measured with a wide jaw
Vernier caliper. The width of the jaw shall be sufficient to span two adjacent
strands, as shown in Figure 1. The minimum resolution value of the Vernier
caliper shall not exceed 0.02mm. The measurement shall be performed on a
straight line 1m away from the end of the steel wire rope without tension.
Measure a diameter on two cross-sections at least 1m apart and in the direction
perpendicular to each other on the same cross-section. The average of the four
measurements is used as the measured diameter of the steel wire rope. The
measured diameter should comply with the allowable deviation specified in
Annex A.
Figure 1 -- Measurement method for steel wire rope diameter
a) A sample is used for the actual breaking tensile test of the steel wire rope;
b) Remove any 3 strands from another sample. 1 strand is for measurement
of stranded steel wire diameter and tensile test. 1 strand is for twist test or
knotted tensile test. 1 strand is for zinc layer weight test. The center steel
wire and outer strand center wire are not tested for mechanical properties.
7.3.4 When a wire rope is cut into several pieces for delivery, several of them
are also tested according to 7.3.1 and 7.3.3 as a coil.
7.4 Determination and reinspection rules
7.4.1 If all the tests meet the requirements, the batch (or strip) of steel wire
ropes is accepted.
7.4.2 If one or more test items do not meet the specified requirements, then re-
sample on the same steel wire rope for re-inspection of failed items. If the re-
inspection result meets the specified requirements, the batch (or) of steel wire
ropes is still accepted.
If one or more re-inspection results do not meet the specified requirements, this
coil of steel wire ropes shall be rejected. The remaining wire ropes of this batch
shall be sampled one by one for testing.
7.4.3 When a steel wire rope is cut into several pieces for delivery, choose one
of them to sample and test. If conforming, the remaining items shall be exempt
from the test, otherwise, samples shall be taken for the test one by one.
8 Packaging, quality guarantee period, transportation,
storage, marks and quality certificate
8.1 Packaging
8.1.1 Spool for winding steel wire rope
The spool for winding steel wire rope is made of high-quality and durable
plywood. The model shall be indicated in the contract. The coil surface shall
have an arrow sign for the direction of the line. Please refer to Annex B for the
spool size of main models.
8.1.2 Rope winding steps
Before winding the rope, the wheel core and the inner side shall be lined with a
layer of neutral moisture-proof paper or plastic film. When winding the rope, the
steel wire rope shall be evenly and flatly wound on the spool. After winding the
......
| Standard ID | GB/T 12753-2020 (GB/T12753-2020) | | Description (Translated English) | Steel wire ropes for conveyer belts | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | H49 | | Classification of International Standard | 77.140.65 | | Word Count Estimation | 14,119 | | Date of Issue | 2020-07-21 | | Date of Implementation | 2021-02-01 | | Older Standard (superseded by this standard) | GB/T 12753-2008 | | Drafting Organization | Fasten Hongsheng Group Co., Ltd., Jiangsu Fasten Special Steel Products Co., Ltd., Jiangsu Shenwang Group Steel Cable Co., Ltd., Metallurgical Industry Information Standards Research Institute | | Administrative Organization | National Steel Standardization Technical Committee (SAC/TC 183) | | Proposing organization | China Iron and Steel Association | | Issuing agency(ies) | State Administration for Market Regulation, National Standardization Administration |
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