阴保程序文件(英文版)_免费下载.docx

阴保程序文件1. PURPOSE. 22. SCOPE. 23. DEFINITIONS. 24. RESPONSIBILITIES 25. DEVELOPMENT 26. DOCUMENTS 27. HEALTH, SAFETY AND ENVIRONMENT1. PURPOSE.The purpose of this procedure is to establish Ldta YPFB activities, for installation of cathodic protection at the bottom of storage tanks and pipes buried or submerged.2. SCOPE.This procedure applies to installing the cathodic protection storage tanks and pipes buried or submerged by the methods of sacrificial anodes and impressed current.3. DEFINITIONS.- 8535-EZ-014-C_SIGNED MEMORIA ESTUDIO DE SISTEMA DE PROTECCIN CATDICA- NACE TM 0497 Measurementes to related techniques to Criteria for Cathodic Protection on Underground or Submerged Metallic Piping System- NACE TM 0101 Measurementes to related techniques to Criteria for Cathodic Protection on Underground or Submerged Metallic Tank Systems- API RP 1632 Cathodic Protection for Underground petroleum storage Tank and Piping Systems- Sacrificial anode: generally specific Metal Magnesium, Aluminum, and Zinc, for the protection of storage tanks and buried or submerged pipelines, metals forming a galvanic couple with iron (Mg-Fe) which will protect from corrosion .- Anode Cathodic Protection Impressed Current: generally specific Metal Fe-Si, graphite, titanium, and other metals used MMO to drain current to the electrolyte in order to protect from corrosion buried or submerged structure.- Reference electrode: A half cell is usually copper or silver copper sulphate silver chloride, calomel, zinc, etc. Used to measure the cathodic protection potential-floor structure.- Electric Potential: Measure voltage between two points, a reference point or zero point and the point to be measured, interface of positive and negative charges.- Thermal welding using metal powder: exothermic welding type consists of metallic powders ignition properties to perform a desired electrical connection between wire to wire or wire-blade4. RESPONSIBILITIES4.1. Manager workProvide the necessary resources to implement the provisions of this procedure.4.2. Electrical and instrumentation Super IntendantDirect and monitor the activities.Implement activities under Policies and Procedures.Review and comply with the provisions of this procedure.Evaluate and verify specific welding procedures.Approve and monitor the activities related to these proceedings.Will be responsible for the inspection, verification, monitor and record the activities related to the activity.4.3. Quality Inspector.Monitor compliance with the provisions of this procedure.Control inspections and checks required by this procedure.To Implement the Quality Plan and Inspection and Test Plan4.4. Cathodic Protection Inspector.The subcontractor will designate a person trained and qualified, which is the one that you track all activities relating to cathodic protection.5. DEVELOPMENT5.1. Technical criteriaThe cathodic protection system must be both impressed current and galvanic current as independent of the existing cathodic protection systems both underground pipes as the inside of the tanks or storage tanks.Cathodic protection systems to be installed metal structures protect the following:- Internal surface of tank storage- Corresponding outer buried surface to the bottom of storage tanks- External surface for buried piping be cathodically protected are those for general planimetry underground networks, storm water and oily water and Firefighting System - Ground.5.1.1. After all equipment has arrived at the field site, according to the package list check the various parts fittings, auxiliary tools, and equipment document shall be complete. When checking the direct current equipment e.g. transformer-rectifier etc., the wire connection of inner section must be firm and reliable. 5.1.2. Before construction, the cathodic protection test posts shall be prepared according to the requirement of the design drawing; the outside size and inner-structure shall be up to standard; the line connection shall be fixed. Before construction, the construction team shall get familiar with the types of test post for different areas based on the design drawing specification and install the post accurately section by section.5.1.3. The posts testing wire is connected with pipeline, using the copper thermal welding method，The color marking of the test conducting wire will be divided according to its function, and shall be uniformed through whole line.5.1.4. The bottom of the storage tanks is usually protected with impressed current system where soil resistivity is high.5.2. Installation of cathodic protection sacrificial anodes.5.2.1. On receiving packaged anodes its integrity is verified, checking the envelopes are not broken and which are free of moisture, additionally checks the electrical continuity between the anode and the conductor cable without compromising the integrity of the package.5.2.2. The galvanic anodes type packaged native soil are filled with compacted at the bottom. 5.2.3. When the anodes and special filler are provided separately, the anodes are centered in the special filler, which filler is compacted prior to native soil and lower inflation.5.2.4. When the sacrificial anodes are used to protect the internal surfaces of the tank bottom, the anodes may be bolted or welded to the bottom of the tanks. The connections are covered, but not the anode surfaces.5.2.5. When using tape type anode at the bottom of the tanks, these are generally installed in clean, dry sand without special padding. The tape is carefully placed so that the anode is not in contact with the bottom of steel.5.2.6. During filling operations cares lead wires and connections are not broken or separated from the anode body for it is not allowed to be taken by the anode wires during transportation and installation.5.2.7. While supplies last cathodic protection facilities, the electrical supervisor in coordination with Quality inspector performs the inspection of the facility to verify their execution according to the designs and subsequently documented in the records.5.3. Installation of impressed current cathodic protection.5.3.1. Prior to installation of impressed current cathodic protection ensures that the structures present protect electrical continuity. For discontinuous structures with metal joints ensures when required.5.3.2. Impressed current anodes are inspected for defects, in accordance with the material specification, size and length of the leads, we review the anode cover is secure and that is not cracked, equal care is maintained while moving and installs the anodes. Cracked anodes are not used.5.3.3. The lead wires are inspected to prevent them from being installed with insulation defects, it is checked that each anode wire is attached to the anode, to avoid failure of the seal between the cable and the anode.5.3.4. Impressed current anodes can be buried vertically, or horizontally with padding and depth according to the design. The padding is installed such that there are no gaps around the anode to ensure electrical contact between the anode and the fill, thus promoting the consumption of filler instead of the anode consumption effectively extending the life of the anode. The carbonaceous filler also tends to reduce the total resistance of the circuit through the resistance drop from anode to ground, the coke filler can also be installed properly shredded and compacted.5.3.5. When installed anodes with negligible wear, requiring no low strength filler, and are installed directly underneath the tank bottom at depths detailed designs.5.3.6. The placement, separation, distance and output current of the anodes and soil resistivity should be considered when calculating the ground voltage gradient necessary to achieve the required soil structural potential according to the criteria of protection. 5.4. Installation anode surface.5.4.1 Before construction, the materials to be used shall be prepared. The specifications and types of all the materials and the equipment shall be in accordance with the engineering specifications and drawing requirement. And any change shall be submitted to the Owners representative for approval.5.4.2. The anodes can be installed vertically or horizontally, to avoid obstacles of rocks, in these cases of high resistance is practical digging a trench for any depth and deposit a shredded Coke horizontal column, usually square in cross section. The anode is placed horizontally in the center of this column.5.4.3. Check the auxiliary anodes material, size, lead length and safety fitting according to the design requirement. The anode shall be taken care of not to be broken or cause damage during shipping and installation.5.4.4. When required to install a mesh anode bed type, the mesh is installed with a minimum depth of 30 cm below the bottom of the tank, in this case the tape type anodes are welded to the bus bars by welding point. 5.4.5. The mesh anode is fed with DC power from the rectifier via cables with insulating covering specified according to design and size.5.4.6. Reference cells are installed and located under the tank according to the design details for a proper functioning cells are placed in a filling layer of low resistivity.5.4.7. Anodes when installed under the tank vent pipes are installed to remove gases electro-chemical reactions that may occur during operation of the anodes.5.4.8. During installation of cathodic protection, the Supervisor of the task along with the quality inspector performs the inspection of the facility to verify their execution according to the designs and documented in the records.5.5. Installing the rectifier.5.5.1. Check that the manufacture of rectifiers classification meets design practices.5.5.2. Check that the power cable connections to the rectifier are mechanically safe and have electrical continuity. Before energizing the power source, it is verified that the negative cable is connected to the structure to be protected and that the positive lead is connected to the anodes.NOTE Caution: If the wires are connected in reverse, with the positive cable incorrectly connected to the tank, the tank bottom will become anode and undergo rapid corrosion.5.5.3. The preferred means for connecting the negative lead of the rectifier to the structure to be protected is through the exothermic welding (eg Cadweld, Thermoweld, or equivalent), however mechanical connections accepted solidly compression fitting. All connections and positive cable joints are waterproofed with resins or insulating tapes.5.5.4.When connecting the wire, based upon the wire connection drawing, check the relation of the alternate and direct current voltage; the electrode of the output power shall be correct and marked the “+” or “” on the wiring terminal.5.5.5. All the equipments earthing system installation shall comply with the related electric equipment specifications. All the equipments side of AC supplying section, a disconnection switch shall be provided, the case shall be ground connected. 5.5.6. When installing underground cable from the positive terminal of the rectifier is reviewed it is completely isolated to prevent the cable acts as an anode and corrode quickly giving rise to the failure of the installation of cathodic protection. Therefore, all of the anode wires, cables and any upper cable splice are carefully inspected before filling.5.5.7. Stuffing free installs sharp stones or other material that could damage the cable insulation. 5.5.8. Before the power will be transferred, the power equipment shall be inspected thoroughly, various plug fitting shall be complete with good and correct wire connection. Each bolt of the main return circuit shall be fixed and firm, the equipment with ground connection shall be reliable.5.6. Equipment, tools and supplies for installation.- Transport of anodes, cables and accessories.- Personal safety equipment.- Metal brushes, tape measure.- Pliers, CADWELD molds, charges, bristle brushes.- Spot welding equipment.- Cold galvanizing, Lubricants, galvanized wire, Paints.- Safety gates and warnings for Exca