Graphite Electrodes Nipples-Used in conjunction with graphite electrodes
Graphite electrode nipples are essential components used in electric arc furnace (EAF) steelmaking processes. These nipples are attached to the ends of graphite electrodes and serve as connectors between the electrodes and the power supply system of the EAF.
Function of Graphite Electrode Nipples
Graphite electrode nipples play a critical role in transferring electrical current from the power supply to the graphite electrodes, which then generates the high temperatures needed for melting scrap steel or other raw materials in the EAFs.
Material of Graphite Electrode Nipples
Graphite electrode nipples are typically made from high-quality graphite materials that exhibit excellent electrical conductivity, thermal stability, and mechanical strength. The choice of material ensures efficient energy transfer and prolongs the lifespan of the electrodes.
Design of Graphite Electrode Nipples
Graphite electrode nipples are designed to withstand the extreme conditions within the EAF, including high temperatures, corrosive environments, and mechanical stresses. They are engineered to provide a secure and reliable connection between the electrodes and the power supply, minimizing the risk of electrical arcing or breakage.
Types of Graphite Electrode Nipples
There are several types of graphite electrode nipples available, including regular power (RP), high power (HP), and ultra-high power (UHP) nipples. The selection of nipple type depends on the specific requirements of the steelmaking process, such as current intensity and furnace size.
Maintenance of Graphite Electrode Nipples
Proper maintenance of graphite electrode nipples is essential to ensure optimal performance and prolong their service life. This includes regular inspection for signs of wear, damage, or oxidation, as well as cleaning and lubrication as needed.
In summary, graphite electrode nipples are critical components in EAF steelmaking operations, facilitating the efficient transfer of electrical energy to the electrodes. Their high-quality construction and reliable performance contribute to the overall efficiency and productivity of the steelmaking process.
Graphite Electrode Nipple Specification
Technical Specification Of Graphite Electrode Nipple
| Item | Resistance (≤, µΩ·m) | Density (≥, g/cm3) | Flexure Strength (≥, MPa) | Elastic Modulus (≤, GPa) | Ash Content (≤, %) | CTE (100 °C – 600 °C) (≤, 10-6/°C) |
|---|---|---|---|---|---|---|
| Regular power | 6.5 | 1.69 | 15.0 | 14.0 | 0.5 | 2.8 |
| High Power | 5.5 | 1.73 | 16.0 | 16.0 | 0.3 | 2.2 |
| Ultra High Power | 4.5 | 1.75 | 20.0 | 18.0 | 0.3 | 1.4 |
Dimensions Of Nipple & Sockets (TPI 3)
| Electrode Dia. | Nipple Designation | Nipple | Socket | ||||
|---|---|---|---|---|---|---|---|
| Major Dia. (mm) | Length (mm) | Pitch Dia. (mm) | Depth (mm) | Thread Length (mm) | |||
| (inch) | (mm) | d1 | l1 | d4 | l2 | l3 | |
| 9 | 225 | 139T3N | 139.7 | 203.20 | 135.49 | 107.60 | 103.60 |
| 10 | 250 | 155T3N | 155.57 | 220.00 | 151.36 | 116.00 | 112.00 |
| 12 | 300 | 177T3N | 177.16 | 270.90 | 172.95 | 141.50 | 137.50 |
| 14/16 | 350/400 | 215T3N | 215.90 | 304.80 | 211.69 | 158.40 | 154.40 |
| 14/16 | 350/400 | 215T3L | 215.90 | 355.60 | 211.69 | 183.80 | 179.80 |
| 16/18 | 400/450 | 241T3N | 241.30 | 338.70 | 237.09 | 175.30 | 171.30 |
| 16/18 | 400/450 | 241T3L | 241.30 | 355.60 | 237.09 | 183.80 | 179.80 |
| 20 | 500 | 273T3N | 273.05 | 355.60 | 268.84 | 183.80 | 179.80 |
| 20 | 500 | 273T3L | 273.05 | 457.20 | 268.84 | 234.60 | 230.60 |
| 22 | 550 | 298T3L | 298.45 | 457.20 | 294.24 | 234.60 | 230.60 |
* The socket minor diameter (d3) is calculated as the pitch diameter (d4) minus 3.16 mm.
* Any alternative combinations of nominal diameter and joint specifications require mutual agreement between the supplier and user.
Dimensions Of Nipple & Sockets (TPI 4)
| Electrode Dia. | Nipple Designation | Nipple | Socket | ||||
|---|---|---|---|---|---|---|---|
| Major Dia. (mm) | Length (mm) | Pitch Dia. (mm) | Depth (mm) | Thread Length (mm) | |||
| (inch) | (mm) | d1 | l1 | d4 | l2 | l3 | |
| 9 | 225 | 139T4N | 139.70 | 177.80 | 136.54 | 94.90 | 90.90 |
| 10 | 250 | 152T4N | 152.40 | 190.50 | 149.24 | 101.30 | 97.30 |
| 12 | 300 | 177T4N | 177.80 | 215.90 | 174.64 | 114.00 | 110.00 |
| 14 | 350 | 203T4N | 203.20 | 254.00 | 200.04 | 133.00 | 129.00 |
| 14 | 350 | 203T4L | 203.20 | 304.80 | 200.04 | 158.40 | 154.40 |
| 16 | 400 | 222T4N | 222.25 | 304.80 | 219.09 | 158.40 | 154.40 |
| 16 | 400 | 222T4L | 222.25 | 355.60 | 219.09 | 183.80 | 179.80 |
| 18 | 450 | 241T4N | 241.30 | 304.80 | 238.14 | 158.40 | 230.60 |
| 18 | 450 | 241T4L | 241.30 | 355.60 | 238.14 | 183.80 | 179.80 |
| 20 | 500 | 269T4N | 269.88 | 355.60 | 266.72 | 183.80 | 179.80 |
| 20 | 500 | 269T4L | 269.88 | 457.20 | 266.72 | 234.60 | 230.60 |
| 22 | 550 | 298T4N | 298.45 | 355.60 | 295.29 | 183.80 | 179.80 |
| 22 | 550 | 298T4L | 298.45 | 457.20 | 295.29 | 234.60 | 230.60 |
| 24 | 600 | 317T4N | 317.50 | 355.60 | 314.34 | 183.80 | 179.80 |
| 24 | 600 | 317T4L | 317.50 | 457.20 | 314.34 | 234.60 | 230.60 |
* Socket minor diameter d3 is equal to pitch diameter d4 minus 3.16 mm.
* Other combinations of nominal diameter and joint are to be agreed upon between the supplier and user.
Standard Electrode Sizes & Nipple Weights
| Electrode | Standard Weight of Nipples | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Nominal Electrode Size | TPI 3 | TPI 4 | |||||||
| Dia. × L | T3N | T3L | T4N | T4L | |||||
| inch | mm | lbs | kg | lbs | kg | lbs | kg | lbs | kg |
| 14 × 72 | 350 × 1800 | 32.0 | 14.5 | – | – | 24.3 | 11.0 | – | – |
| 16 × 72 | 400 × 1800 | 45.2 | 20.5 | 46.3 | 21.0 | 35.3 | 16.0 | 39.7 | 18.0 |
| 16 × 96 | 400 × 2400 | 45.2 | 20.5 | 46.3 | 21.0 | 35.3 | 16.0 | 39.7 | 18.0 |
| 18 × 72 | 450 × 1800 | 62.8 | 28.5 | 75.0 | 34.0 | 41.9 | 19.0 | 48.5 | 22.0 |
| 18 × 96 | 450 × 2400 | 62.8 | 28.5 | 75.0 | 34.0 | 41.9 | 19.0 | 48.5 | 22.0 |
| 20 × 72 | 500 × 1800 | 79.4 | 36.0 | 93.7 | 42.5 | 61.7 | 28.0 | 75.0 | 34.0 |
| 20 × 84 | 500 × 2100 | 79.4 | 36.0 | 93.7 | 42.5 | 61.7 | 28.0 | 75.0 | 34.0 |
| 20 × 96 | 500 × 2400 | 79.4 | 36.0 | 93.7 | 42.5 | 61.7 | 28.0 | 75.0 | 34.0 |
| 20 × 110 | 500 × 2700 | 79.4 | 36.0 | 93.7 | 42.5 | 61.7 | 28.0 | 75.0 | 34.0 |
| 22 × 84 | 550 × 2100 | – | – | – | – | 73.4 | 33.3 | 94.8 | 43.0 |
| 22 × 96 | 550 × 2400 | – | – | – | – | 73.4 | 33.3 | 94.8 | 43.0 |
| 24 × 84 | 600 × 2100 | – | – | – | – | 88.2 | 40.0 | 110.2 | 50.0 |
| 24 × 96 | 600 × 2400 | – | – | – | – | 88.2 | 40.0 | 110.2 | 50.0 |
| 24 × 110 | 600 × 2700 | – | – | – | – | 88.2 | 40.0 | 110.2 | 50.0 |
Coupling Torque Reference For Nipple & Electrode
| Electrode Diameter | inch | 8 | 9 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| mm | 200 | 225 | 250 | 300 | 350 | 400 | 450 | 500 | 550 | 600 | |
| Easing Moment | N.m | 200–260 | 300–340 | 400–450 | 550–650 | 800–950 | 900–1100 | 1100–1400 | 1500–2000 | 1900–2500 | 2400–3000 |
