Casing pipe used for crossing of roads and rivers may represent a problem to cathodically protected pipelines. To ensure that the complete functionality and protection is maintained over time, casing pipe crossing should be carried out according all the applicable good practice standards. The internal pipeline (“carrier pipe”) shall be mechanically and electrically isolated by the casing pipe using specially designed spacers. Proper sealing on both ends shall be ensured by the use of suitable and durable rubber end-seals. Casing pipes should have no coating to allow cathodic current to be discharged to the carrier pipe in case of failure of the sealing. Additional Zinc ribbon anodes can be used as additional protection. Ventilation pipes should be used on both sides of the carrier pipe to prevent the formation of condensation.
Product list:
- Pipeline insulating collars;
- Rubber end seals;
- Zinc ribbon;