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
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Where an alternative is offered, any variations from this part of ISO should be identified. Significant positive shifts in pipeline potential, such as those due to stray-current interaction, shall be corrected within 30 days Annex B. Alternatively, connections between the positive cable to the transformer-rectifier and the individual anode cables may be made below ground using fully encapsulated line taps.
Every care has been taken to ensure that the file is suitable for use by ISO member bodies. Impressed-current anode cables should be connected to the positive feeder cable inside an above-ground distribution box to enable current monitoring. Annex D provides information on various types of specialized survey. Annex A gives details of the measurements. Generally, voltages higher than 50 V rectifier output should be avoided. A simulation on a computer might be required to optimize the number, location and resistance-to-earth of the earthing systems.
On-land pipelines 1 Scope This part of ISO specifies requirements and gives recommendations for the pre-installation surveys, design, materials, equipment, fabrication, installation, commissioning, operation, inspection and maintenance of cathodic protection systems for on-land pipelines, as defined in ISOfor the petroleum and natural gas industries.
ISO – Standards Australia
External corrosion control in general is covered by Jso Monitoring stations and distribution boxes shall be accessible during all seasons and shall be designed and located to minimize vandalism or accidental damage.
A panel-mounted meter should be provided to enable the pipe-to-soil potential to be read.
If there are changes in soil characteristics, more measurements shall be taken. Care shall be taken to ensure that isolating devices are not unintentionally electrically by-passed after installation. These surveys are normally conducted by trained personnel using purpose-built equipment and instrumentation.
Results provided by the remote monitoring system should be periodically checked against manually recorded data to ensure kso the remote monitoring system is functioning correctly.
As the voice of the U. If the area to be surveyed is affected by seasonal changes, these shall be taken into account and the most severe conditions with respect to the soil conditions shall be used for the design. Coupon 1558-1 potentials are more accurate if measured against a permanent reference electrode buried alongside the coupon or permanently built in as a facility polarization probe.
Alternative materials isi be used if their performance relevant to the specific operating conditions are reliable and documented. NOTE Other direct 1589-1 sources, equalizing currents, telluric currents and interference currents can influence the measurement and therefore give results which are not the true polarized potential.
The requirements for detection 155891- control of electrical interference are contained in Annex B. Measurements of corrosion potentials should be carried out at the monitoring stations prior to energizing the CP system.
They walk either in-line directly over the pipeline or side-by-side with one operator over the pipeline. They shall be io for use as a baseline for future verifications of CP effectiveness. EN Valves for natural gas transportation in pipelines – Performance requirements and tests.
This will normally require the transformer-rectifier output voltage to be increased at these times to satisfy the current demand. Annex B shall apply with respect to the detection and control of ieo currents. In urban or industrial areas, the intervals should not be greater than 1 km. Conduites terrestres ww w. Transformer-rectifier units and current drainage stations shall be visually checked for serviceability and damage at least annually see Because a large amount of data is produced, a field computer or data logger is normally used and the information later downloaded to produce plots of pipeline potential versus distance from the fixed reference point.
A typical composition of magnesium anodes is given in Table 3. The chosen technique should be selected on the basis of local conditions in the field, e.