Product Overview
Graphite electrode nipples are key components used to connect graphite electrodes in metallurgical furnaces (such as electric arc furnaces and ladle furnaces). They ensure stable current conduction and mechanical strength under high-temperature and high-current conditions. Standard nipples are typically made from high-quality needle coke and precision-machined to meet international specifications (e.g., UHP, HP, RP grades).
Key Features
High Conductivity: Low resistivity (typically ≤6.5 μΩ·m) for efficient current transfer.
High-Temperature Resistance: Withstands temperatures above 1500°C (optional anti-oxidation coating available).
Mechanical Strength: High flexural strength (≥15 MPa) and precise threading to prevent breakage or loosening.
Low Thermal Expansion: Minimizes thermal stress deformation, extending service life.
Precision Threading: Complies with ISO/ANSI standards (e.g., NPT threads, 3/4 taper threads) for seamless connection.
Main Types & Specifications
By Material Grade:
Regular Power (RP): For small-to-medium furnaces.
High Power (HP): Suitable for high-load furnaces.
Ultra-High Power (UHP): For large electric arc furnaces with ultra-high current density.
Size Range: Diameter 75–700 mm, length 200–1200 mm (customizable).
Thread Standards: 3/4 taper, 1/5 taper, parallel nipples, etc.
Applications
Steelmaking: Electric arc furnaces, ladle refining.
Industrial Silicon/Phosphorus: Submerged arc furnace conductive systems.
Others: Calcium carbide, corundum production, and other high-temperature electric furnaces.
Quality Certifications
Complies with ISO 9001, ASTM D5602, and other international standards.
Third-party tested for resistivity, bulk density, thermal shock resistance, etc.
Usage & Maintenance Tips
Installation: Use a torque wrench for proper tightening (e.g., UHP nipples typically require 300–500 N·m).
Storage: Keep dry and avoid impact to prevent thread damage.
Lifespan: Regular thread inspection; anti-oxidation coatings can extend lifespan by 20%+.
Competitive Advantages
|
Feature |
Graphite Nipple |
Metal Nipple |
|
High-Temp Resistance |
★★★★★ |
★★☆☆☆ |
|
Conductivity |
★★★★☆ |
★★★☆☆ |
|
Thermal Shock Resistance |
★★★★☆ |
★★☆☆☆ |
Supplier Services
OEM customization, technical support, and after-sales service.
Packaging: Wooden crates/foam, labeled with batch numbers and specifications.
For detailed technical parameters (e.g., resistivity, strength data) or application cases, please specify your requirements.
Types of Graphite Electrode Nipples
1. By Material & Power Grade
|
Type |
Properties |
Applications |
|
RP (Regular Power) |
Higher resistivity (8–12 μΩ·m), lower mechanical strength, cost-effective. |
Small arc furnaces, FeSi/CaC₂ production. |
|
HP (High Power) |
Moderate resistivity (6–8 μΩ·m), good thermal shock resistance. |
Medium steelmaking/ladle furnaces. |
|
UHP (Ultra-High Power) |
Ultra-low resistivity (≤6 μΩ·m), high strength (flexural ≥18 MPa), oxidation-resistant. |
Large arc furnaces, ultra-high current density. |
2. By Thread Type
|
Type |
Features |
Standards |
|
3/4 Taper Thread |
Universal use, 3/4 inch per foot taper (~62 mm/m), easy alignment. |
U.S. standards (e.g., UC/UD). |
|
1/5 Taper Thread |
Flatter taper (1/5 inch per foot), tighter fit, anti-loosening. |
Europe/Japan (e.g., NPT). |
|
Parallel Nipple |
For large electrodes (≥600 mm), uses bolts for enhanced stability. |
Custom designs. |
|
Straight Thread |
Non-tapered, requires nuts; used in special equipment. |
Niche applications. |
3. By Function & Structure
|
Type |
Purpose |
|
Standard Nipple |
Basic connection, no coating. |
|
Anti-Oxidation Coated |
Surface-treated (e.g., Al-Si coating) for extended high-temperature life. |
|
Composite Nipple |
Metal-reinforced core (e.g., carbon fiber) for extreme conditions. |
|
Quick-Change Nipple |
Optimized threading for rapid replacement, reducing downtime. |
4. By Size
Diameter: 75–700 mm (e.g., Φ300 mm, Φ450 mm).
Length: 200–1200 mm (custom lengths available).
Selection Guide
Steelmaking Arc Furnaces: Prioritize UHP + 3/4 taper threads.
Submerged Arc Furnaces (Si/P): HP + anti-oxidation coating for cost efficiency.
High-Current Applications: Verify resistivity and current capacity compatibility.
Products Parameters
|
Item |
Unit |
Diameter 550(556-562)Mm |
|||
|
UHP Graphite Electrode |
Nipple |
||||
|
Guaranteed |
Typical |
Guaranteed |
Typical |
||
|
Resistivity ≤ |
UΩ*M |
6.3 |
5.0-6.0 |
5.3 |
3.8-4.5 |
|
Flexural Strength≥ |
MPA |
10.5 |
11.0-13.0 |
20 |
20-25 |
|
Young's Modulus≤ |
GPA |
14 |
8-12 |
20 |
12-16 |
|
Bulk Density≥ |
G/CM3 |
1.66 |
1.68-1.73 |
1.75 |
1.76-1.82 |
|
CTE(100 ℃-600℃) ≤ |
10-6/℃ |
1.5 |
1.3-1.5 |
1.4 |
1.0-1.3 |
|
ASH ≤ |
% |
0.5 |
0.2-0.4 |
0.5 |
0.2-0.4 |
Note：We can provide lengths of 2000/2200/2400mm for UHP500 graphite electrodes. Of course, we can also customize the length according to customer requirements.
Recommended Current Load Of Electrode
|
Grade |
Inch |
Nominal Dia |
Allowable current |
Current density |
||
|
AC |
DC |
AC |
DC |
|||
|
UHP Graphite Electrode |
10 |
250 |
10000-13000 |
- |
14-18 |
- |
|
12 |
300 |
13500-20000 |
- |
14-18 |
- |
|
|
14 |
350 |
20000-32000 |
- |
20-32 |
- |
|
|
16 |
400 |
25000-41000 |
- |
20-32 |
- |
|
|
18 |
450 |
32000-49000 |
- |
20-30 |
- |
|
|
20 |
500 |
40000-60000 |
- |
20-30 |
- |
|
|
22 |
550 |
45000-68000 |
49000-78000 |
18-28 |
20-32 |
|
|
24 |
600 |
52000-81000 |
58000-93000 |
18-28 |
20-32 |
|
|
26 |
650 |
60000-85000 |
64000-100000 |
18-28 |
20-32 |
|
|
28 |
700 |
71000-100000 |
79000-120000 |
18-27 |
20-30 |
|
|
30 |
750 |
82000-123000 |
91000-135000 |
18-27 |
20-30 |
|