Ring Pair Corrosion Monitor : RPCM RPCM is an in-line, piggable, monitor for pipelines, flow lines and process pipework giving true corrosion rate measurement in all service conditions due to full inner diameter, with flow through geometry. The exceptional resolution of the embedded CEION metal loss measurement technology makes RPCM a unique effective tool for flow assurance applications. Main features: Pro-active tool - for management of pipeline corrosion in real time. Confirms corrosion inhibition performance and allows optimization. Targetable on key risks such as preferential weld or localized corrosion. Provides complete information due to 360º coverage and sector discrimination. Enhances pipeline management information with measurements of other key process variables. Unrestricted application in subsea, buried or process plant conditions.
Low cost of operation maintenance free. Clear information data output is in engineering units. The service design life of RPCM exceeds asset design life and pressure integrity is assured by the double barrier built into the device, allowing RPCM to be installed subsea, buried or in remote locations. The standard operating envelope is up to 2500# and 180ºC with design options for High Pressure/High Temperature deepwater operations. Installation can be by flanged connector, hub or welding. The instrumentation features low power electronics with an intrinsically safe data logger option or hyperbaric pods capable of up to 2000m seawater service. The Ring Pair concept The Ring-pair design consists of co-axially spaced closed rings pairing a corrosion-sensing ring with a ceramic coated electrically isolated reference ring. The process flow is unimpeded through the rings. The arrangement provides the optimum compensation for temperature and stress, while it closely simulates the corrosion interface at the internal wall of the pipeline. Precise monitoring of metal loss from thick rings is possible by virtue of the high resolution of CEION measurement system. RPCM Measures and Reports Temperature Experience in this field has demonstrated that there may be temperature variations either localized or general within the process, especially in multiphase process courses.
The unique features of CEION technology allow to derive temperature from ring measurement. This not only allows a temperature compensation, but also provides a valuable additional output of the process information for corrosion management. A better representation from analysis of sectors Pipeline corrosion is rarely uniform so it is important to detect localization of the corrosion attack. RPCM theory provides model of analysis by sectors. Optional dispositions of co-axially spaced logging points around the external surface of the rings allow us to obtain a radius segment resolution of metal and temperature loss. This feature provides better representation, and therefore better control.
A faster response through ring pairs When response speed is really important, a Ring Pair configuration is used. A ring sensitive that is sensitive to corrosion is thinner, usually as thick as the pipeline corrosion tolerance, it is supported by a second electrically insulated ring that provides the necessary mechanical strength. On average, response time to corrosion rate change can be typically 4 or 5 times faster than a ring of complete wall thickness, ideal for a fine adjustment of the inhibitor dosage. Does it affect temperature measurements? No, the measured response will change with temperature, but CEION also manages a temperature measurement from the sensor therefore, if the temperature changes, or the rate of change is significant, correction algorithms are applied. Does it affect stress measurements or liquid-gas flow? No, any kind of tension can create minor effects, but these are eliminated through compensation built into the design. Do intelligent pigging or cathodic protection affect the measurements? No, the high flow created buy intelligent pigging might create a temporary noise blip in the results, but there is no sensitivity to residual magnetism in the pipe. CEION is not affected by cathodic protection. Multiple Materials The unique RPCM concept allows various pairs of rings in one device. Diverse materials can be studied, including welding and hazardous material if preferential corrosion of the welding is a concern.
A safe construction of the Spool RPCM spools are constructed using the double-block principle. An inner spool, consisting of pairs of rings, spacings and seals, is capable of withstanding design pressure and is the primary contention.. The inner spool is sealed into an outer envelope capable of equalling the pressure, providing a secondary contention. Outer spool construction can be welded or an RTJ type joint can be used. Electrical connections to the rings pass through high integrity glass penetrators welded into the outer envelope.
About CEION Technology Cross-section schematic of Spool CEION is state-of-the-art technology for metal loss measurement. It can detect amounts of material loss in minutes, while these are being corroded or eroded by the effects of gas and oil production in pipelines, containers and flowline. CEION applications include: Corrosion management and inhibitor optimization of onshore facilities. Subsea systems such as flowline, subsea manifolds and wellheads. Long life monitoring of baseline localizations and safe access to problematic localizations. Each application group has its own thought out solutions, tailored to meet the needs of application engineering to be really cost-effective. Complying with pipeline and pressure container design codes ensures that each design can be totally certified. Completely welded design has been awarded by DNV for subsea service according to the BS8010 Pt3 y BS4515. The spool can be coupled to the pipeline with flanges, hubs, or welding.
Low power electronics. RPCM spool electronics is constructed into a separate instrument connected to the penetrators by coupling subsea connectors and connection or bridge cables. Portable subsea containers can be repaired through divers or (Remotely Operated Vehicles) for easy repair in case of damage. Power consumption is low, about 100 ma to 24 V per ring pair. Battery use and data logging are available options. Flexible Communications. Communications have been designed with a considerable flexibility, allowing RPCM to be easily connected with other telemetry and control packages. Apart from conventional telemetry by cable, data can be recovered by acoustic transmission, using data transmission system or in harware memory modules. Solutions to Incrustations and Pitting RPCM platform can be used in personalized Incrustation and Pitting solutions. These options are developed with the customer and the Cormon s FAO group (Flow Assurance & Optimization Group) to achieve the specific goals of each project. With options ranging from 4 to 40 and instrumentation packages for onshore, buried or subsea facilities, RPCM is the flexible high resolution solution for corrosion management in pipelines.
Photo: Onshore application of a gas receptor platform of a 4 RPCM unity of 2500# nominal internal diameter. Support Although RPCM output data are in easy-to-understand engineering units, corrosion data must be related to the key operative parameters and plant history to be used with better results. Cormon s Flow Assurance & Optimization Group provides a wide range of services that add value into the support to products such as RPCM including: data interpretation health care support integrated system design total system management
Comparison of typical Resolutions -------------------------------------------------------------------------------------------------------------------- Measurement Thickness resolution [microns] ------------------------------------------------------------------------------------------------------------------------- General corrosion of a 16 CEION, RPCM stool of 17.5 mm wall thickness. ± 1,0 Sector of 60 of a 16 CEION, RPCM stool of 17.5 mm wall thickness. ± 3,0 General corrosion of a 16 CEION, RPCM ring pair of 17.5 mm wall thickness. ± 0,2 Sector of 60 of a 16 CEION, RPCM ring pair of 17.5 mm wall thickness. ± 0,75 CEION F80, 3 NB Corrosion or Erosion subsea probe. ± 0,3 CEION F80, (2 NB surface probe). ± 0,018 Conventional F20 ER (electrical resistance) probe under stable temperature conditions. ± 0,5 Non-intrusive NDT in 16 of 17.5 mm pipe wall. ± 17,5 Technical Data Sheet (GLO 6.Catalogue)