Pipeline Process Corrosivity Measurement Using Mechanical Diaphragm Sensors

Traditional corrosion monitoring techniques tend toward those which are suited for cumulative loss measurement (e.g. Electrical Resistance) or rapid corrosion rate measurement (e.g. Linear Polarization Resistance), but generally not both in the same package.  Furthermore, electrochemical techniques can be confounded by variations in process conductivity and multiphase flows.   A newly developed process corrosivity sensor bridges the gap between traditional ER and LPR sensors by monitoring cumulative mass loss with sufficiently high resolution to permit very rapid corrosion rate assessment.   The primary sensing element is mechanical in nature, not relying on process conductivity, and is suited to a wide range of processes, such as potable water, oil and gas, chemical, and electric power applications.

The corrosion sensing system operates on a diaphragm-based principle, where the diaphragm is a surrogate element that corrodes similarly to the pipeline.  Small changes in diaphragm thickness can be detected by monitoring the diaphragm response to the applied pressure intrinsic to the pipeline process.  In addition to laboratory data obtained under representative environmental conditions, this paper presents the real-world experience gained from the recent field prototype demonstration of the sensor technology in an Army potable water distribution system.

This material is based upon work supported by the Small Business Innovation Research (SBIR) Program and the Engineer Research and Development Center-Construction Engineering Research Laboratory under contract W9132T-06-C-0017.