In the world news as well as generally throughout the public domain we commonly find large, transnational pipeline projects – Northstream, Southstream, Bluestream, etc. – that are planned and discussed over years and therefore the object of widespread attention. But the major part of pipelines transporting the various types of liquids and gasses is far from the global spotlight, buried in the ground and methodically fulfilling its purpose for more than 50 years. The risk of an explosion caused by external damage or simply by corrosion is much higher at these installations than at newly built pipelines, which are usually equipped with modern control and monitoring technology. For more aged pipelines comprehensive oversight should be a top priority. An ideal combination for retrofitting pipelines without reconstruction is a periodical inspection using intelligent PIGs – preventive and sensitive but with reaction periods of years – together with computational pipeline monitoring – quick reaction, robust and easy installation. The ad-vanced version “LEO-Pipe Compliance Kit” of MAGNUM’s monitoring solution was especially designed for retrofitting existing pipelines to meet compliance with TRFL and API-1130. The presentation briefly describes the principles of model-based pipeline monitoring. In practical applications at old and existing pipeline systems several obstacles will be found that stem from the broad range of involved technologies: installed sensors, control solutions, weak or missing data links, operation modes, etc. To prevent huge engineering costs caused by special solutions a set of standard components is defined and described. Main units besides the central monitoring station are specialized remote stations (RT-Stations) providing modularized sensor interfaces, robust communication, and GPS based synchronization. Pre-processing and buffering of measured data is the solution to cope with weak, slow, and unreliable communication links. The presentation also shows some practical applications of LEO-Pipe and demonstrates the achievable improvements by a pre-configured kit. Finally some experimental results are shown that demonstrate high precision leak location designated for a special anti-theft application.