To aid location fixing of specific features, dents or weld ingress etc. which can stop a pig, PBS offer pulse transponders, which can be tracked on land or sub-sea, with ROV equipment. Additionally, magnetic units are used in hazardous environments requiring the maximum safety credentials. Existing Pipelines When a pipeline is in operation, the inner surface of the line may be subject to scale formation, wax / paraffin formation, surface corrosion due to the type of product in the line, and the operating conditions. In addition, there may be situations where repairs or modifications have been carried out and it becomes necessary to revalidate the line for service in a safe and effective manner.