What Is The National Standard For Tension Clamps?
1 Scope of application
This standard applies to tension clamps for fixing small and medium-section aluminum stranded wires and steel-core aluminum stranded wires on tension towers for overhead power lines and substations.
2 Types and dimensions
2.1 Suspension Clamp are NLD and ND types.
2.2 The main dimensions of the tension clamps shall comply with the provisions of Figures 1, 2 and Tables 1 and 2:
The meanings of the letters and numbers in the models in the table are:
N——tension; L——bolt; D——inverted; number——applicable conductor combination number.
3 Technical requirements
3.1 The general technical conditions of the tension clamps shall comply with the provisions of GB2314-85 "General Technical Conditions for Power Fittings".
3.2 Materials and fasteners
a. The body of the tension clamp shall be made of steel with a tensile strength of not less than 372.5N/mm2 (372.5MPa) in accordance with GB700-79 "Technical Conditions for Ordinary Carbon Structural Steel" or forged iron with a grade of not less than KT33-8 in accordance with GB978-67 "Classification and Technical Conditions for Forged Cast Iron Parts";
b. The U-shaped screw shall be made of steel with a tensile strength of not less than 372.5N/mm2 (372.5MPa) in accordance with GB700-79 "Technical Conditions for Ordinary Carbon Structural Steel";
c. The nut shall be made of GB 41-76 "Hexagonal Nut (Rough)";
d. The washer shall be made of GB 95-76 "Washer (Rough)";
e. The spring washer shall be made of GB 93-76 "Spring Washer";
f. The pin shall be made of SD 29-82 "Flat Head Pin";
g. The closed pin shall be made of SD 26-82 "Closed Pin".
3.3 The breaking load of the tension clamp shall not be less than the following values:
NLD-1, ND-201 type 18.4kN;
NLD-2, ND-202 type 41.0kN;
NLD-3, ND-203 type 71.0kN;
NLD-4, ND-204 type 91.0kN.
4 Acceptance rules and test methods
The acceptance and test of the tension clamp shall be carried out in accordance with GB2317-85 "Acceptance rules, test methods, marking and packaging of power fittings".
5 Marking and packaging
The marking and packaging of the tension clamp shall be carried out in accordance with GB 2317-85.
Additional notes:
This standard is proposed by the Ministry of Water Resources and Electric Power of the People's Republic of China.
This standard is drafted by the Nanjing Electric Power Fitting Design Institute of the Ministry of Water Resources and Electric Power.
The main drafters of this standard are Dong Ji'e, Zhou Mingze, Yi Jianxing, Luo Yizu, Yu Tianqu and Bo Tong.
