technical of TENSION CLAMPS(DEAD END CLAMPS)
1. Ultimate Tensile Strength (UTS)
1. UTS is the maximum axial load the clamp can withstand before mechanical failure.
2. Clamps are designed to equal or exceed the conductor’s rated tensile strength.
2. Working Load / Safe Working Load (SWL)
1. SWL is generally 1/2.5 to 1/3 of the UTS, ensuring safe long-term operation.
2. Typical SWL Range:
I. 20 kN to 60 kN, depending on the clamp and conductor size.
3. Designed to sustain full conductor tension under extreme wind, ice, or load imbalance conditions.
3. Conductor Diameter Compatibility
1 Clamps are conductor-specific to ensure full grip without damage.
2. Typical Range:
I. 16 mm to 35+ mm for various ACSR and AAAC conductors.
3. Customized liners or inserts are used to match the clamp to the exact conductor size.
4. Slip Strength:
1. The clamp must prevent slippage of the conductor under tension.
2. Minimum slip strength:
I. ≥ 95% of the conductor's UTS.
3. Verified by applying tension in type testing as per IEC 61284 / IS 2486.
5. Temperature Withstanding Capacity:
1. Should operate reliably across varying ambient and fault conditions.
2. Operating Range:
I. -40°C to +120°C (normal)
II. Short-term tolerance up to 250°C during overloads or faults.
3. Materials and coatings are selected for thermal durability.
6. Corrosion Resistance:
1. Designed for harsh outdoor, coastal, and polluted environments.
2. Material & Coating:
I. Clamp Body: Ductile iron / High-strength aluminum alloy
II. Bolts & Nuts: Hot-dip galvanized or stainless steel
III. Galvanizing as per ASTM A153 / IS 2629
3. Minimum zinc coating thickness: 80–100 µm (HDG)
7. Impact & Fatigue Strength:
1. Must endure:
I. Wind-induced vibration
II. Galloping from ice/snow
III. Mechanical impact during installation or tensioning
2. Tested to survive >10⁷ vibration cycles without cracking, loosening, or fatigue.
8. Mechanical Endurance:
1. Expected mechanical life: 25–30 years under normal service conditions.
2. Must retain:
I. Grip strength
II. Structural integrity
III. Corrosion protection
3. Long-term performance proven through type testing and accelerated aging.
9. Design Safety Factors:
1. UTS vs Working Load:
2.5 to 3.0×
2. Slippage Threshold:
≥ 95% of conductor UTS
3. Thermal Safety Margin:
~2× continuous rating
4. Mechanical Fatigue:
>10⁷ cycles (high endurance)
Top 5 Quality Assurance
1. Compliance with Relevant Standards
Manufactured as per applicable national and international standards such as IS 2486 (Part 1 & 2), IEC 61284, ASTM, or ANSI, ensuring mechanical integrity, performance, and safety under tension load.
2. Material Quality and Certification
I. Raw materials (e.g., aluminum alloy, galvanized malleable/ductile iron, steel) are tested for:
II. Accompanied by Material Test Certificates (MTCs) to ensure input quality.
3. Mechanical Load and Slip Resistance Testing
I. Ultimate Tensile Strength (UTS) test
II. Slip strength test
III. Safe Working Load (SWL) test
IV. Ensures the clamp can hold the conductor firmly without slippage or deformation under load.
4. Corrosion Resistance & Surface Treatment
I. All metallic parts are hot-dip galvanized or coated with anti-corrosive material as per IS 2629/ISO 1461.
II. Zinc coating thickness is checked (typically ≥85 microns) for long-term outdoor performance.
5. Final Inspection, Marking & Documentation
I. Each clamp undergoes visual, dimensional, and fitment checks before packing.
II. Products are marked with manufacturer’s logo, batch number, and conductor range.