Zinc Earthing Cell
Monday, 14 May 2018 00:00
Zinc earthing cells
Creation of high potential difference between two parts of the flange is possible due to the induction or occurrence of flashover , which results destruction of flange insulation. This event happens in part of pipelines which is used for insulating two parts of pipeline from insulating kit at the flange position. So, zinc anodes are used as earthing electrode in order to prevent these problems. The chemical composition of these electrodes is similar to buried zinc anodes in soil which are produced according to ASTM B418 (Type 2) standard. Zinc earthing cells can be binary or quaternary. Also, their collections stay on like earthy zinc anodes in backfill (usually containing 75% Gibson, 20% bentonite and 5% sodium sulfate). Details of this equipment is as following figure:
1.Unprotected pipeline
2.Insulated flange
3.Cathodic protection pipeline
4.Connection of zinc earthing cell to pipeline
5.binary zinc earthing cell
6.Special backfill with low resistance
Copper cable is used as a resistant material for connection with a cross-section of 10 mm2 or 16 mm2. Also, this cable is welded to steel core inside the electrode. The connection point between the copper cable and steel rod is coated with epoxy resin.
Also, Dimension and Weight of zinc earthing cells are as follows:
W |
L |
Weight |
Code NO. |
40 | 914 | 22/11 | 110 EBC |
30 | 1525 | 20/10 | 100 EBC |
36 | 1525 | 26/13 | 130 EBC |
40 | 1525 | 34/17 | 170 EBC |
45 | 1525 | 44/22 | 220 EBC |