STANDARD. ISO. First edition. Petroleum and natural gas industries —. Cathodic protection of pipeline transportation systems —. Part 1. Purchase your copy of BS EN ISO as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards. STANDARD. ܚ. ISO. First edition. an Petroleum and natural gas industries -. Cathodic protection of pipeline transportation systems
|Published (Last):||25 March 2010|
|PDF File Size:||18.34 Mb|
|ePub File Size:||8.55 Mb|
|Price:||Free* [*Free Regsitration Required]|
ISO – Standards Australia
The current output from anodes should be independently adjustable. A panel-mounted meter should be provided to enable the pipe-to-soil potential to be read. If the isolating device is bonded across, such that the pipeline is electrically continuous with a plant earthing grid, then 15589-11 the resistance-to-earth of the grid shall be estimated or the grid itself shall be part of the study.
Significant positive shifts in pipeline potential, such as those due to stray-current interaction, shall be corrected within 30 days Annex B. Although we endeavour to is an up-to-date catalogue, on occasion we may not have the latest version of a document, including where it has not yet been provided through an international feed. Adobe is a trademark of Adobe Systems Incorporated.
Coupon instant-off potentials are more accurate if measured against a permanent reference electrode buried alongside the coupon or permanently built in as a facility polarization probe. The requirements for detection and control of electrical interference are contained in 155891- B. They walk either in-line directly over the pipeline or side-by-side with one operator over the pipeline. For such metals, the potential shall not be more negative than a limiting critical potential El.
Each negative drain shall be provided with a shunt and diode preventing mutual influence of pipelines during on-potential and off-potential measurements see Annex A. Results provided by the remote monitoring system should be periodically checked against manually recorded data to ensure that the remote monitoring system is functioning correctly.
A number of specialized survey techniques exist which provide additional detailed information on the status of the pipeline corrosion prevention system. Cathodic protection of the carrier pipe within the casing can be improved by earthing the casing using steel earthing rod s. For dated references, only the edition cited applies.
When the CP system is energized, the drainage current should also be recorded. A current interrupter should be installed at the nearest transformer-rectifier or a temporary current source to achieve a significant potential change approximately mV on the pipeline.
NOTE 2 Possible effects associated with a. A further objective can be to collect data for optimization of future CP designs. Cables shall be sized such that no excessive voltage drops occur which reduce the capacity of the system. This will normally require the transformer-rectifier output voltage to be increased at these times to satisfy the current demand. In selecting the location and type of groundbeds to be installed, the following local conditions shall be taken into account: Possible sources of detrimental d.
This part of ISO is also applicable to retrofits, modifications and repairs made to existing pipeline systems. Typical examples where this could occur include excessively negative potentials 5. Where the protective coating is in good condition, the current will attenuate at a constant rate, which depends upon coating properties. For high strength steels specified minimum yield strength greater than MPa and corrosion-resistant alloys such as martensitic and duplex stainless steels, the limiting critical potential shall be determined with respect to the detrimental effects in the material due to hydrogen formation at the metal surface.
Already Subscribed to this document. Measurements of corrosion potentials should be carried out at the monitoring stations prior to energizing the CP system. We recommend that you check the website of the publishers of the international document before making a purchase.
Where multiple negative connections are installed, separate shunts and blocking diodes shall be provided. Specific methods to be considered, individually or in combination, are as follows: The metallic casing shall be electrically isolated from any structures on the surface. The entire content of this part of ISO is applicable to pipelines on land and piping systems in other industries used and transporting other media, such as industrial gases, water or sludge.
Galvanic anodes shall be marked with the type of material e. NOTE If the a.
Proceed to Checkout Continue Shopping. The criterion for CP is therefore E u Ep The protection potential of a metal depends on the corrosive environment electrolyte and on the type of metal used. Permanent monitoring facilities connected to the pipeline should be installed simultaneously with the pipeline lso allow monitoring of the performance of the temporary system. Your Alert Profile lists the documents that will be monitored. Monobloc isolating joints should be used wherever possible.
A simulation on a computer might be required to optimize the number, location and resistance-to-earth of the earthing systems. The design, materials, dimensions and construction of the isolating joints shall meet the design requirements of ISO After installation of the cable-to-pipe connection, the coating shall be repaired using a suitable coating material. NOTE Other direct current sources, equalizing currents, telluric currents and interference currents can influence the measurement and therefore give results which are not the true polarized 155891.
A partly defective isolating device may not be readily identifiable by this method, since the current in the bond may not be zero if the leakage resistance and the bond resistance have similar magnitudes.
Cables should be made of copper and shall be insulated and sheathed to oso the prevailing chemical and mechanical soil conditions.