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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As such, these potentials should not be used to determine the effectiveness of the CP on the pipeline. As a general guide a potential difference of less than mV may be regarded as inconclusive. Consideration should be given to the risk of the coating becoming disbonded during its service life and the resulting possibility for corrosion due to shielding of CP current.
The transformer-rectifier shall be left at this setting until the pipeline is polarized. For an effective instant-off potential measurement, all sources of CP current to the pipeline shall be switched off simultaneously. CP potentials measured on thermally-insulated pipelines are usually not indicative of the potentials which exist at the metal-to-electrolyte interface beneath the coating.
The potential gradients caused by coating defects will then be the mean values of the potentials between the reference electrodes at locations 2 and 3 and at points 2 and 4arranged symmetrically with the distance, L, in Figure D.
NOTE 1 It can be assumed that the coupon metal will adopt a potential, with respect to the adjacent soil that is similar to the pipe-to-soil potential at a coating defect iao the same size on the pipe. Significant positive shifts in pipeline potential, such as those due to stray-current interaction, shall be corrected within 30 days Annex B. The electrodes at positions 1, 2, 3 and 4 are used to measure structure-to-electrolyte potentials and potential gradients using the intensive measurement technique.
Use of continuous conductive polymer anodes should be considered, particularly for very lso resistivity soils 15598-1 the pipeline. It shall consist of two separate cables attached to each individual pipeline, terminating in a monitoring station with facilities to install direct or resistive bonds if required. Full documentation 15589- number, types, mass, dimensions, chemical analysis and performance data of the anodes shall be provided. From each monitoring station, at least two separate cables shall be attached to the pipeline.
Performance of the CP monitoring equipment, e. For non-metallic casings and coated steel casings, if usedCP should be provided to the pipeline inside the casing by installing galvanic anodes or impressed-current polymer anodes along the bottom of the pipe, together with a reference electrode inside the casing.
BS EN ISO 15589-1:2017
The ratio of the on- to off-periods shall be chosen to avoid significant depolarization. Drainage stations Measure drain-point potential and the current at least monthly Connections to foreign pipelines Measure current flow at least annually Bonding devices and grounding systems Measure electrical continuity at least annually Safety and protection devices Measure settings and function at least annually At monitoring stations Measure instant-off potentials annually a Less frequent measurements may be considered based on results of specialized surveys see Standards Subsctiption may be the perfect solution.
In these cases, alternative criteria shall be verified and applied. At the drain point, a monitoring station should be installed using a separate test cable connected to the pipeline, for the measurement of the drain point potential. ISO consists of the following parts, under the general title Petroleum and natural gas industries — Cathodic protection of pipeline transportation systems: Other practical reference electrodes to CSE may be used for the various criteria provided that their properties are reliable and documented.
Adobe is a trademark of Adobe Systems Incorporated. In the event of interference resulting in the CP criteria not being met, remedial action shall be taken to eliminate the interference. Vent pipe material shall be manufactured from a non-metallic chlorine-resistant material. NOTE Metallic casings only provide temporary borehole stabilization, as the metal will be consumed by the d.
Protection measures against a. The probes are normally held parallel to and directly above the pipeline, enabling the direction of current flow to the defect to be determined.
The formation or decay of polarization shall be measured in accordance with A. Any protective barrier coating applied to prevent the ingress of dirt, or the absorption of water by insulating materials shall be kept in good condition.
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. Normally, all large coating defects can be identified if measurements are made at intervals of 5 m along the pipeline. In the presence of currents from remote foreign sources, the potential gradients will be no longer symmetrical.
The basic design shall include a calculation of the groundbed resistance based upon the most accurate soil resistivity data available. This standard is also available to be included in Standards Subscriptions. We recommend that you check the website of the publishers of the international document before making a purchase. In case of low soil resistivity, high a.
In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. Before specifying the d. The minimum conductor size for measurement cables should be 4 mm2.
This corrosion rate is sufficiently low so that corrosion will be within acceptable limits for the design life. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
Please first log in with a verified email before subscribing to alerts. The metallic casing shall be electrically isolated from any structures on the is. The following information should be considered in the design of the pipeline CP system: In urban or industrial areas, the intervals should not be greater than 1 km.
ISO – Standards Australia
ISO shall not be izo responsible for identifying any or all such patent rights. The measurements should be carried out for a period of at least 24 h, or a period which is typical for the suspected interference phenomenon being investigated, to assess the time dependence of the interference level. In areas where there could be an unacceptable risk of high voltages on the pipeline exceeding the joint’s electrical capacity, e.
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.
NOTE High voltage gradients in the soil in the vicinity of groundbeds can be a hazard to animals and persons. The calculation shall be carried out for the unused anode bed.
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. Add ios Alert PDF.