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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The design, materials, dimensions and construction of the isolating joints shall meet the design requirements of ISO Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. In the event of interference resulting in the CP criteria not being met, remedial action shall be taken to eliminate the interference.
Current density requirements also depend upon the oxygen content and resistivity of the soil. When carrying out potential measurements in coastal areas where the soil contains high amounts of chloride salts, CSE shall not be used. Cable routes should be marked using cable markers installed jso approximately m intervals and at every isso of direction.
The requirements for detection and control of electrical interference are contained in Annex B. The cables of galvanic anodes should be connected to the pipeline in an above-ground distribution box to allow current monitoring and disconnection of each individual anode. The actual resistance measured can therefore be a combination of these three and the measurement of a low resistance value is not always a reliable indication that the isolating device is defective.
Annex D provides information on various types of specialized survey. This can be a dedicated layer iao addition to a corrosion-protection layer or it can be a layer such as polyurethane or rubber which 15859-1 both corrosion protection and thermal insulation. If the isolating device is bonded across, such that the pipeline is electrically continuous with a plant earthing grid, then either the resistance-to-earth of the grid shall be estimated or the grid itself shall be part of the study.
Thus, the potential measurement with the 155891- electrode at the ground surface will include a contribution from the IR ios. Annex 1558-91 shall apply with respect to the detection and control of interference currents. A carbonaceous or other conductive backfill material shall be used unless the soil conditions give a satisfactory groundbed resistance, the soil is homogeneous and uniform consumption of anodes is expected.
BS EN ISO 15589-1:2017
A panel-mounted meter should be provided to enable the pipe-to-soil potential to be read. However, when there is a series of defects close together, and specific information on a particular defect is required, the side-by-side method is preferred.
For cables to galvanic anodes, the minimum cross-section should be 4 mm2. Whenever the effectiveness of an isolating device is tested on site, the integrity of any accompanying high-voltage protection device shall also be checked in accordance with the manufacturer’s instructions. Generally, the larger the defect, the greater the current flow and voltage gradient. Groundbeds can suffer from drying out at certain times of the year, evidenced by an increase in the groundbed electrical resistance.
For dated references, only the edition cited applies. Ieo both cases, the pipe-to-soil potential shall be recorded lso at least 24 h. Making transverse readings with one electrode located at the epicentre of the coating defect, anodic and cathodic characteristics can be determined. NOTE Special conditions sometimes exist where cathodic protection is ineffective or only partially effective. Alternatively, the CP may be accomplished by the use of galvanic anodes, the limitations of which are given in Clause 7.
Conduites terrestres ww w. If the potential on the other side of the isolating device does not change, or changes in value in the opposite direction due to an interference effectthe isolating device may be considered to be effective. Further guidance on methods for mitigating d. Remedial actions shall be taken if periodic tests and inspections indicate that protection is no longer adequate.
This corrosion rate is sufficiently low so that corrosion will be within acceptable limits for the design life. Two operators walk along the route, making the necessary contacts with the soil, usually via cleated boots. A monitoring station is not required if the drain point is installed on an above-ground section of the pipeline.
All sealing, coating and insulation materials shall be resistant to the fluid transported. Alternatively, the space between the casing and the pipeline should be filled with a material with adequate long-term corrosion protection properties. The removal of the protective coating from the pipe should be kept to a minimum. Users of this part of ISO should be aware that further or differing requirements may be needed for individual applications.
Performance of the CP monitoring equipment, e. Usually, the interfering current from a foreign source, not electrically continuous with the affected pipeline, is drained from the soil by the affected pipeline. To avoid isso effects on the CP, the earthing systems should be connected to the pipeline via appropriate devices, e.
ISO – Standards Australia
Vent pipe material shall be manufactured from a non-metallic chlorine-resistant material. Follow these links to find other Standards similar to the one you are viewing. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
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. This part of ISO is applicable to buried carbon steel and stainless steel pipelines on land. Using a sensitive millivoltmeter, 1558-1 potential difference is measured between two reference electrodes probes placed at the surface level in the soil within the voltage gradient.
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. The monitoring plan shall include at least the following: If their use 15589-11 unavoidable, the casing shall be designed to cause minimal interference with, or shielding of, the CP.
From each monitoring station, at least two separate cables shall be attached to the pipeline. The number of measurements should be based on local soil conditions.
In sections where a. In case of low soil resistivity, high a. In carrying out the survey, the operator walks the pipeline route taking measurements at typically 2 m intervals with the probes one in front of the io, 1 m to 2 m apart. There are complementary techniques which can be used to give a more accurate assessment of the effectiveness of the CP.
Pipeline attenuation calculations can be carried out to define the spacing between drain points and anodes. For thermite welding on live pipelines, a safety procedure shall first be developed, addressing the following: