[Standard Analysis] anti-twist wire rope for tension stringing of transmission line (dl/t 1079-2016 traction rope and guide rope)

1. Preface

This standard is drafted according to the rules of GB/t1.1-2009. This standard is a revision of dl/t1079-2007 anti-twist steel wire rope for tension stringing of transmission lines. Compared with the original standard, the main contents of this revision are as follows:

1. a) The standard name is changed to anti-twist steel wire rope for tension setting out of transmission line;
2. b) In the chapter on classification and marking code, delete the contents classified according to the number of shares in the same series in the classification of anti-torsion steel wire rope;
3. c) In the chapter on classification and marking code, the comparison table of square diameter and strand diameter is modified, and the strand diameter as the standard series in the original standard is modified to the nominal square diameter as the standard series;
4. d) In the chapter on technical requirements, 1570mpa, 1670mpa, and 2060mpa of nominal tensile strength of steel wire are deleted;
5. e) In the technical requirements section, the conversion factor K of the minimum breaking force is taken as 0.85.

This standard is proposed by and under the jurisdiction of the China Electricity Council. This standard is drafted by: China Electric Power Research Institute, Henan Lanxing Power Machinery Co., Ltd., Jiangsu Xinhua metal products Co., Ltd., Yangzhou Qianyuan Electric Equipment Manufacturing & Trade Co., Ltd., Yangzhou Zhendong Power Equipment Co., Ltd. and Jiangsu Changhong Machinery Co., Ltd. Drafters of this standard: Lizheng, wanjiancheng, housing, Jiangming, Pengfei, tangguangrui, Xia Yongjun, Liu Kai, jiaoguojie, Gong Xiaobo, Liang Wei, xuzhongren, wanchangjun. This standard replaces dl/t1079-2007 after implementation. This standard is the first revision. The opinions and suggestions during the implementation of this standard shall be fed back to the standardization management center of the China Electricity Council (No. 1, 2nd Baiguang Road, Beijing, 100761).

1. scope

This standard specifies the classification, marking code, technical requirements, test methods, inspection rules, packaging marks, quality certificates, and other requirements of anti-twist steel wire ropes. This standard applies to the guide rope, traction rope used in the tension setting out the construction of transmission lines, and the anti-twist steel wire rope required to be non-rotating in other applications.

2. normative references

The following documents are essential for the application of this standard. For dated references, only the dated version applies to this standard. For undated references, the latest edition (including all amendments) applies to this standard. GB / T 2104 general provisions for packaging, marking, and quality certificate of steel wire rope GB / T 8358 determination of actual breaking force of steel wire rope GB / T 8706 terminology, marking and classification of steel wire rope GB / T 20118 general purpose steel wire rope Nb / SH / T 0387 grease for steel wire rope Yb / T 5343 round steel wire for rope

3. terms and definitions

The following terms and definitions apply to this standard.

3.1 anti twisting steel wire rope is also known as braided anti-twisting steel wire rope, also known as nontwisting steel wire rope, or non-rotating steel wire rope. A group of left twist and a group of right twist round strand ropes are regularly braided (crossed spiral tracks), in which the number of left twist strands and right twist strands are equal and symmetrically braided, and the two groups of spiral torques are balanced due to the opposite directions so that the steel rope has the characteristics of no rotation under stress. This standard refers to the torsion-proof steel wire rope with a square and hexagonal structure.

3.2 strand diameter refers to the diameter of round strand wire rope used to weave anti-twist wire rope, unit: mm.

3.3 dimension of the distance between two symmetrical planes of the anti-torsion steel wire rope, unit: mm.

3.4 nominal square diameter nominal dimension of the distance between two symmetrical planes of the anti-torsion steel wire rope, unit: mm. 3.5 mass per meter the net mass of the anti-twist steel wire rope under the condition of no oil is divided by the measured length of the steel wire rope, and the unit is kg / m.

3.6 pitch lay pitch strand rope rotates around the axis for one circle (360) The distance between the corresponding two points, in mm.

3.7 pitch diameter ratio is the ratio of the pitch to the nominal square diameter of the anti-twist steel wire rope.

3.8 cross-sectional area is the sum of the nominal cross-sectional area of steel wire in steel wire rope, including filler wire, in mm.

3.9 minimum rated breaking force (F0) the minimum force to be reached when the anti-torsion steel wire rope is broken, unit: kn.

3.10 the product of the total sectional area of the steel wire in the steel wire rope and the nominal tensile strength of the steel wire, unit: kn.

4. classification and mark code

4.1 classification of anti-twist steel wire rope

The anti-twist steel wire rope can be divided into squares and hexagonal according to the section shape. As shown in Figure 1 and Figure 2, it can be divided into 8 shares, 12 shares, and 18 shares according to the number of shares. See Table 1 for the specific classification and table 2 for the comparison between square diameter and stock diameter.

Analysis of minor composition: the guide rope and traction rope are divided into two categories: square and hexagonal. If they are subdivided, they are divided into three types: 8-strand, 12-strand, and 18 strands. They should be distinguished before use on the construction site. The specific type of traction rope should also be specified in the construction scheme or stringing calculation. It cannot be expressed in square diameter only. In fact, according to the tensile strength of the steel wire, it should be noted whether it is 1770mpa, 1870, or 1960mpa. The square diameter is the same, but the shape, several strands, and strength grade of the steel wire are different, so the mechanical properties also differ greatly.

4.2 marking 4.2.1 marking code

4.2.2 the first bit of code meaning: y refers to anti-twist steel wire rope (see GB/t 8706). Bit 2: indicates the appearance shape, the square is represented by s, and the hexagonal is represented by L. Bit 3: indicates nominal square diameter, standard series, such as 11mm, 13mm, 18mm, 32mm, etc. The fourth digit indicates the number of shares, such as 8 shares, 12 shares, 18 shares, etc. Bit 5: indicates the number of steel wires in the strand and the structural type in the strand, such as 19W (Warrington type), 19S (Xilu type), 25fi (filled type), 29fi (filled type), and 31sw (Xiwa type) (see Appendix A). Bit 6: represents the minimum breaking force of steel wire rope (integer), in an. Example 1:ys13-8 × 19W 105。 Meaning: anti-twist steel wire rope, square, nominal square diameter 13, 8 strands, 19 wires in strands, structural Wallington type, minimum breaking force of steel wire rope 105kn. Example 2:yl30-12 × 25Fi 520。 Meaning: twisted steel wire rope, hexagonal, nominal square diameter 30, 12 strands, 25 wires, structural filling type, minimum breaking force of steel wire rope 520kn.

5. technical requirements

5.1 nominal square diameter

The nominal square diameter of anti-torsion steel wire rope shall comply with the provisions in Table 2; It is calculated according to the diameter and number of shares and rounded. The nominal diameter not listed in Table 2 shall be negotiated by the supplier and the demander and indicated in the order contract.

5.2 unit mass weight

Unit mass = (total cross-sectional area of steel wire in steel wire rope × 10-6 × seven thousand eight hundred and fifty × 1.06), in kg/m. The actual mass of the anti-twist steel wire rope (excluding the oil coating mass) shall not exceed ± 5% of its unit mass. 5.3 materials

5.3.1 steel wire for rope 5.3.1.1 steel wire for strand rope shall meet the requirements of yb/t 5343, and the nominal tensile strength of steel wire is 1770, 1870, and 1960mpa.

5.3.1.2 the joints of steel wires in the anti-torsion steel wire rope shall be as few as possible. The steel wires with a diameter greater than 0.6mm shall be connected by butt welding, and the steel wires with a diameter less than 0.6mm can be connected by butt welding or plug connection. In the same twisting of strands, the distance between each connection point in the strand shall not be less than 5m.

5.3.1.3 all steel wires in the galvanized anti-torsion steel wire rope shall be galvanized, and the galvanizing quality shall comply with the provisions of GB/t 20118.

5.3.2 the strand rope (sub rope) for rope making shall be supplied by a professional steel wire rope factory and shall comply with the relevant provisions of YB/t5343 and GB/t20118.

5.3.3 the core of anti-twist steel wire rope generally adopts natural fiber.

5.3.4 oil the anti-torsion steel wire rope. The grease used for the anti-torsion steel wire rope shall comply with the provisions of nb/sh/t 0387 and other standards. It shall be noted when it is required not to apply oil.

5.4 weaving method of anti-twist steel wire rope

The strands of the braided steel wire rope are twisted left or right, and the braiding method is that the left and right strands account for half respectively, showing a regular spiral cross braiding state.

5.5 weaving quality

5.5.1 during the weaving of anti-twist steel wire rope, every single strand of steel wire shall maintain a certain tension, to ensure that each strand of steel wire can be stressed evenly. No joint of any kind is allowed for each strand of rope, and no joint is allowed for the outer steel wire of the finished rope.

5.5.2 the pitch diameter ratio of the anti-twist steel wire rope shall be kept between 10~14; The pitch of each rope shall be uniform, and the pitch fluctuation shall be within ± 10%.

5.5.3 both ends of the anti-twist steel wire rope shall be inserted with rope sleeves. The pitch shall ensure that the inserted strand rope cannot be pulled out. The insertion length of the rope sleeve shall not be less than 4 times the pitch and not less than 300mm. The plug shall be gradually changed evenly, the end of the strand rope shall be welded, and the cut-off end shall be buried in the rope. If the user requires not to insert the rope sleeve, both ends shall be tied tightly.

5.5.4 the ridge line of the outward contour of the anti-torsion steel wire rope axis shall be parallel to the steel wire rope axis, and shall not be a diagonal or spiral line. The appearance shape shall be regular quadrilateral and regular hexagon, and no skew quadrilateral or skew hexagon is allowed.

5.5.5 the twisted steel wire rope shall be free from such defects as broken wires, missing wires, staggered wires, loose wires, bent wires and wires, poor joints, uneven pitch, wavy, lantern-shaped, kink, flattening, poor oiling, corrosion, etc. (see GB/t 8706 for the definition of defects).

5.6 mechanical properties and section structure of anti-torsion steel wire rope

5.6.1 mechanical properties of anti-torsion steel wire rope after multiplying the total calculated breaking force of anti-torsion steel wire rope by the conversion coefficient K of minimum breaking force, its value is equal to the minimum breaking force of anti-torsion steel wire rope in Table 3 ~ Table 8. The minimum breaking force of anti-twist steel wire rope is calculated according to the following formula:

Where: f0- minimum breaking force of anti-torsion steel wire rope, kn; Fn- total calculated breaking force of steel wire, kn; A-cross sectional area of steel wire in steel wire rope (see Table 3 to table 8), mm ²；σ- Nominal tensile strength of steel wire, MPa; K-conversion coefficient of minimum breaking force, taken as 0.85.

6. inspection and test methods

6.1 appearance quality inspection

The weaving quality and appearance quality of the anti-twist steel wire rope shall be inspected by hand feeling and visual inspection. The anti-twist steel wire rope shall not have the following defects: broken wire, staggered steel wire, poor insertion of rope sleeve, loose strand, loose strand, uneven pitch, loose strand, wavy, lantern-shaped, kink, poor oiling, surface damage, wear deformation, mechanical wear, diameter thinning, corrosion, etc.

6.2 measurement of the square diameter

6.2.1 measure when 10%f is applied to the anti-twist steel wire rope.

6.2.2 the square diameter of anti-twist steel wire rope shall be measured with a vernier caliper with a wide jaw, which shall be wide enough to span two adjacent strands.

6.2.3 the measurement shall be carried out at a straight line 5m away from the end of the anti-torsion steel wire rope, on two adjacent sections of at least 1m, and in different directions of the same section. The average value of the measurement results shall be taken as the measured square diameter of the anti-torsion steel wire rope, and the allowable deviation of the measured square diameter shall not exceed ± 10% of its nominal square diameter.

6.3 measurement of pitch

Under the condition of applying 10%f, measure any strand at any three straight positions 3M away from the end of the anti-twist steel wire rope, and take the average value as the pitch. The allowable pitch deviation shall be 0 ~ +5%.

6.4 measurement of unit mass

Under the condition of no oil, apply 10%f, measure 1m length of anti-torsion steel wire rope, and make marks on both ends. After unloading, cut 1m samples according to the marks, and measure the sample mass with a balance. The measured unit mass of anti-twist steel wire rope is expressed in kg/m.

6.5 measurement of strand diameter

Disassemble the anti-twist steel wire rope into a single strand, and measure the diameter of the strand rope with a vernier caliper. The diameter shall be the average value of two readings at the position at right angles to each other on the same circumference, rounded to one decimal place in mm; Measure 3 times at different positions and take the average value. Allowable deviation of strand diameter: 0 ~ +8% for 3.0mm and below; 0 ～ +7% for 3.5mm ～ 5.0mm; 0 ～ +6% for 5.5mm and above.

6.6 breaking force test of anti-torsion steel wire rope

6.6.1 the braking force of the anti-twist steel wire rope is divided into the measured braking force F of the whole rope and the sum of the measured braking force FJ of the steel wire.

6.6.2 the method for measuring the braking force of the whole rope of anti-twist steel wire rope shall be carried out according to the provisions of GB/t 8358, and the measured breaking force of the whole rope f ≥ F0.

6.6.3 the total measured breaking force FJ of anti-torsion steel wire rope shall meet FJ ≥ FN.

Where: fj- total measured breaking force of steel wire, kn; F’- measured breaking force of any strand, kn; N- number of strands of anti-twist steel wire rope. The test strand shall not be less than 50% of the total strands of the anti-twist steel wire rope.

7.1 inspection items

The product inspection is divided into delivery inspection and type test, and the inspection items are shown in Table 9. The type test report shall be issued by a third-party testing institution with steel wire rope testing qualification.

7.2 acceptance method and sampling

7.2.1 the acceptance of the demander can be entrusted to the testing department qualified for testing the anti-torsion steel wire rope. The acceptance is based on this standard and the order contract (in case of any dispute between the supplier and the demander over any test result, the arbitration test shall be conducted in a third-party inspection institution agreed by both parties. The arrived ropes for the arbitration test can be sampled one by one or randomly).

7.2.2 during acceptance, the breaking force of anti-torsion steel wire rope shall be carried out according to the test method specified in 6.6.2 of this standard. The acceptance test items of anti-twist steel wire rope shall be determined according to the agreement between the supplier and the buyer.

7.2.3 for the anti-twist steel wire ropes produced in the same batch, of the same structure, of the same nominal square diameter, of the same nominal tensile strength, and the same surface state, samples shall be taken from any three discs, and the breaking force of the whole rope shall be measured according to the method specified in GB/t 8358. If the order quantity is less than three sets, samples shall be taken according to the agreement between the supplier and the buyer. 7.2.4 the anti-twist steel wire rope manufacturer shall provide the user with all the data of the steel wire test of the strand rope manufacturer, such as the measured diameter of the steel wire, tensile strength, repeated bending times, torsion, knotting tension, zinc coating quality, etc.

7.3 re-inspection and judgment rules

7.3.1 if all tests meet the requirements, the batch (or piece) of anti-twist steel wire rope is qualified.

7.3.2 if one or more test items do not meet the specified requirements, the steel wire rope is unqualified, and other steel wire ropes are double sampled for re-inspection. If the re-inspection results meet the specified requirements, the batch (or pieces) of steel wire rope is still qualified. If the re-inspection does not meet the specified requirements, the batch of steel wire rope is unqualified.

7.3.3 when a twisted steel wire rope is cut into several sections for delivery, one of them shall be sampled for test. If it is qualified, the other sections shall be exempted from the test. Otherwise, samples shall be taken one by one for the test.

7.4 the arbitration test shall be carried out by the provisions of this standard and the purchase contract.

8. packaging, marking, and quality certificate

8.1 the packaging, marking, and quality certificate of anti-twist steel wire rope shall be by the provisions of GB/t 2104. 8.2 the supply length deviation of anti-twist steel wire rope shall not exceed 0 ~ +20m.

8.3 when the anti-twist steel wire rope is delivered from the factory, steel identification rings shall be set on the rope sleeves at both ends, and the identification rings shall include the following contents: a) date of delivery; b) Name of the manufacturer; c) Specification and model.

Analysis: for newly purchased steel wire rope, relevant quality certificates shall be kept, including manufacturer qualification, production license, quality certification, product type report, certificate of conformity, test report, etc., and the steel wire rope shall be submitted to the supervisor for review before mobilization.

Precautions for use of anti-twist steel wire rope

1. the safety factor of guide rope and traction rope shall not be less than 3. The safety factor of guide rope and traction rope for special crossing and stringing shall not be less than 3.5.
2. the connecting parts of the ends of the guide rope and the traction rope shall be inspected by a specially assigned person before use, and shall not be used in case of damage to the steel wire rope.
3. the anti-twist steel wire rope shall be regularly inspected according to relevant regulations, and great attention shall be paid to maintenance.
4. the use of anti-twist steel wire rope shall be subject to special inspection before stringing construction.
5. the anti-twisted steel wire rope shall not pass through the lifting pulley, and shall not be used by splicing. It is also not allowed to go through the winch drum. After the test, if the winch drum is ground and the force is 3 tons, the braking force of the primary anti-twist steel wire rope (traction rope or guide rope) under the force is lost by 30%. At the same time, it is forbidden to anchor directly to the angle iron pile. After the test, when the anchor is anchored to the angle iron pile and the force is 2 tons, the braking force is reduced to 50%.