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 (mm)	L (mm)	Weight (Kg)	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