Veriforce TG CCT 412OP. Training Guide

Transcription

1 Training Guide Directions: This training guide is to be used by a Veriforce Authorized Evaluator/Trainer and Trainee during on-thejob training (OJT) or prior to an evaluation as a resource. (S) Indicates a demonstration or skill task; (K) indicates a knowledge task. OJT Reminder: OJT is an active hands-on process. Practice should be as similar to the actual job task as possible. However, if the training is being provided on an actual job site while a covered task is actually being performed, the Evaluator either needs to be qualified on that covered task or be assisted by someone who is qualified on the covered task. The Evaluator should closely monitor the Trainee's practices to ensure safe and correct task performance. At no time should a non-qualified individual perform, or train for, a covered task unless directed and observed by a qualified individual. However, if the span of control for that particular covered task is 1:0 (requiring only qualified individuals to perform the covered task), the training must be simulated. Training is simulated by "walking through" the task and simulating all actual manipulations (valves, switches, tools, etc.) an individual would use during the performance of a covered task. Simulating includes the use of safety and administrative requirements as if the task were being performed live. Refer to the Veriforce Evaluator Training Program for more on how to conduct formal OJT. Disclaimer: This training resource is offered in good faith. Anyone choosing to utilize or rely on this training resource is doing so at their own discretion, risk and choice. Although every attempt has been made by Veriforce, LLC (the Company ) to ensure the correctness and suitability of this document and to correct any errors brought to the attention of the Company, the Company makes no representation or warranty regarding correctness or suitability (either directly or indirectly) of information referenced or implied within this training resource. In no event shall the Company be liable for any damages (including, but not limited to, special, incidental or consequential damages) whatsoever (including, but not limited to, death, personal injury, damage to person or property, loss of use, and/or loss of revenues), whether in an action of contract, negligence, or other action, arising out of or in any way associated with the use or misuse of this document. All critical information should be independently verified by the user and the user shall not rely on the contents provided herein without such independent verification. The subject matter included in this training has been compiled from a variety of sources and is subject to change without notice. The Company reserves the right to add, remove and alter information contained in this document without notice. The Company may provide links to other sites for your convenience; however, the Company takes no responsibility and makes no representation or warranty regarding the accuracy or currency of information contained within such sites. The Company does not endorse any information, goods, or services referred to within such sites, and the provision of links by the Company shall not be interpreted to be an endorsement of such information, goods or services. The content of this training resource is provided for personal use only, and all other use, copying or reproduction of this training or website or any part of it is prohibited. CCT: 412OP Install CP Leads on Pipeline Using Exothermic Weld Page 1 of 8 Copyright 2018 Veriforce, LLC. All rights reserved. 08/02/2018

2 Recommended Student Training or Resources: Recommended Student Training or Resources: DOT 49 CFR DOT 49 CFR Install CP Leads on Pipeline Using Exothermic Weld Knowledge Explain what is required prior to performing this task. Pipeline Operator-Approved Procedures and Appropriate Equipment/Material Prior to performing this task, you will need to have the pipeline operator-approved procedures as well as the appropriate equipment and materials. The procedures will outline requirements for performing this task that are specific to the pipeline operator. Operators may also have specific requirements regarding the type of equipment that can be used to perform this task. Therefore, it s important to follow the specific requirements of the procedures and only use operator-approved equipment. Doing so can ensure the task is performed correctly and according to the pipeline operator s standards. Knowledge Describe how to verify pipeline wall thickness and location. Cathodic protection cables (CP leads) are an important component of cathodic protection (CP) systems. Generally, CP leads are constructed of stranded copper and are insulated with a polyethylene or other plastic compounds that provide excellent chemical and moisture resistance. These cables are designed to act as direct current feeders to electrically charged metallic structures, such as pipelines. CP leads are connected to the pipeline through exothermic welding (among other methods) at various intervals and as specified by each pipeline operator. Exothermic welding (also referred to as thermite welding) is a welding process for joining two electrical conductors, in this case, a pipeline and a copper lead. This process uses a high temperature reaction charge of powdered copper oxide and aluminum, which when ignited, produces aluminum oxide and super-heated copper. Exothermic welding requires no external power or heat source. As a result, its portability makes it a preferred method for connecting CP leads to pipelines in the field. High quality CP leads are essential for a CP system to prevent corrosion. Equally important is knowing how to install them properly. The following is a basic example of how to install CP leads through exothermic welding. Refer to your pipeline operator s requirements for applicable and specific procedures. The first step in installing CP leads through exothermic welding is to verify the location and thickness of the pipe. The location of where the weld will be performed is defined by the specific operator requirements. Consult with the pipeline operator to verify the proper product, line number, station number, and wall thickness. The wall thickness must be determined before removing the coating from the area to be welded. Page 2 of 8 Copyright 2018 Veriforce, LLC. All rights reserved. 08/02/2018

3 The purpose of verifying the wall thickness is to ensure the pipe wall meets the operator specifications in order to perform the exothermic procedure. Some pipeline operators require wall thickness to be measured through the use of an ultrasonic (UT) device. (Refer to your specific operator for wall thickness verification.) Skill Demonstrate how to prepare pipe surface. After the pipe wall thickness has been determined, the next step is to prepare the surface. The surface of the pipe should be sanded or filed to bare metal and must have a bright, shiny, clean, and dry surface before welding the cable connection. Be careful not to gouge the parent metal. You should file only what is necessary to clean the pipe. Consult with your pipeline operator s specifications for applicable instructions. However, a good practice is to remove an area the size of the bottom of a typical mold in order to minimize the amount of coating to repair. Proceed and remove the coating and any dirt, mill scale, oxide, grease, moisture, or other foreign matter from the weld area. It s important to double check the pipe wall thickness regularly throughout the preparation process in order to ensure the wall thickness remains within the pipeline operator s specifications. Once the coating has been removed and bare metal is visible, remove any existing film on the pipe with an approved solvent cleaner. Wipe the solution off with clean rags or brushes and rinse well with detergent and water to clean away any residue of contaminant or solvent. Take precautionary measures to ensure that no liquid or moisture is left after using the solvent solution. The surface area must be clean and dry. Knowledge Describe how to select location of exothermic weld, exothermic weld size and appropriate furnace/mold. Once the area has been cleaned, verify and select the exothermic weld location. Ensure that the weld is at a reasonable distance from any existing welds. If more than one connection is required at a location, the connections should be staggered along a line in a longitudinal direction and spaced out accordingly. Refer to your specific operator s requirements for applicable procedures. After the location of the exothermic weld has been established, the appropriate mold needs to be determined. Semi-permanent graphite molds are used to create accurate exothermic connections. These molds control the direction and speed of the molten weld metal, flow, and final shape. Most molds last an average of 50 to 100 welds. When selecting the appropriate mold, you must first determine the wire gauge as well as the pipeline diameter. Generally, American Wire Gauge (AWG) #10 or 12 is used for test stations, but heavier wire (AWG) #4 can also be used. Most molds created and designed for pipeline use can accommodate any size wire/cable. If the cable is of a smaller size, copper adapter sleeves are available. Manufacturers of exothermic welding supplies provide charts and catalogs that can assist with the selection of proper mold and cable sleeves. The type of mold is also determined by the diameter of the pipe. For example, a smaller diameter pipe may require a mold that has a bottom curvature in order for the mold to sit tight on top of the pipe. In addition, a mold can also be determined by pipeline shape, wire position of attachment, and other specified criteria. Just as there are many different types of molds, there are also many types of weld powder charges. Weld metal is packaged in moisture-resistant plastic cartridges (tube shaped). The charge size and weight of the cartridge are marked on each individual tube casing. The size of the welding charge is determined by the wall thickness, type of mold, and by the type of pipe the leads will be attached to. Page 3 of 8 Copyright 2018 Veriforce, LLC. All rights reserved. 08/02/2018

4 Usually, a 15 gram charge size is sufficient enough for attaching (AWG) #4 wire/cable or smaller. However, there is a multitude of different charge sizes for different types of connections and scenarios. It is vitally important that the correct charge be used; it is possible to damage the pipe, creating an extreme safety hazard if you burn through a loaded line. For example, different charge sizes are required for each of the following types of connections: Copper-to-copper Copper-to-steel Copper-to-copper clad steel Copper-to-cast iron Copper-to-rail Furthermore, within each type of connection there is a variety of different charge sizes. Manufacturers of weld material supply catalogs and charts as references that determine the appropriate charge sizes based on various factors, such as wall thickness and pipeline composition. Lastly, it s important to mention that improper selection of exothermic weld material along with poor pipe preparation are perhaps two of the leading causes of unsuccessful exothermic connections. It is fundamental that you follow all preparation procedures set forth by the manufacturer and pipeline operator. Doing so will greatly reduce the possibility of a poor connection. Skill Demonstrate installation of CP leads using exothermic procedure and test integrity of weld/adhesion. The following is a basic demonstration and simulation of how to install CP leads using an exothermic procedure. There are significant hazards associated with exothermic welding. The welding material is an exothermic mixture and reacts to produce hot molten material with temperatures in excess of 2500ºF and a localized release of smoke. Refer to your pipeline operator s requirements for specific instructions. When performing this procedure, remember to wear personal protective equipment (PPE) and avoid performing this procedure in areas of flammable gas. Use detection equipment to ensure the atmosphere is safe. Ensure that you comply with all safety conditions during the process. Before installing CP leads through exothermic welding, ensure that all necessary equipment is available and ready to use. The equipment typically consists of the following: Test leads (cables) Exothermic graphite mold Mold handle clamp Welding material Steel disc Weld caps Flint igniter Page 4 of 8 Copyright 2018 Veriforce, LLC. All rights reserved. 08/02/2018

5 Wire brush Wire cutters Blow torch (if necessary) Copper adapter sleeves (if necessary) Once all equipment is accounted for, prepare the exothermic mold. Remove and clean slag, dirt, and other foreign matter from the mold. A graphite mold tends to absorb moisture, so make sure to remove any moisture and dry out the inside of the mold thoroughly. Often a blow torch is used to dry out the mold by heating it up. Warning: Do not ignite welding material with blow torch; use the flint igniter. Remove the insulation on the CP leads as required to fit the mold, avoiding damage to exposed copper wire. It is recommended to cut the cable with a wire cutter to prevent deforming the cable ends. Remove only enough insulation from the cable to allow the weld connection to be made. If the wire is cut or nicked, cut off the damaged part and strip a new end. In addition, if the manufacturer requires the use of a copper adapter sleeve, crimp it securely to the wire and remove any excess wire protruding from the end of the sleeve. CP leads should also be cleaned and dried. Scrape the outer surface to remove dirt and oxidation from the leads. Note: It is necessary to separate wire strands into two or more bundles when attaching large (AWG) size cables. In such cases, make sure that each strand is welded separately in order to prevent the leads from causing stress concentration on the pipeline. Insert the CP leads into the graphite mold and position the mold at the selected area to be welded as specified by the pipeline operator s requirements. Next, use the steel disc found inside the packaging box of the welding material. Insert the disc (concave side up) into the mold. Ensure the disc is properly seated. Load the mold. Take a tube of welding material (cartridge) and remove the lid over the mold. Pour the loose welding material powder into the mold. The bottom of the tube contains compressed starting material. Tap the bottom of the tube a couple of times to loosen this material and pour some of it on top of the welding material inside the mold. Close the lid of the mold and pour the remaining starting material into the slot on the mold cover. Aim the flint igniter at an angle and ignite the starting material on the mold cover. Make sure you have all of your safety equipment on before ignition of starting material. The welding material will react to weld the CP lead to the specified area of the pipe. Allow approximately 30 seconds for completion of reaction; then remove the mold. Once you remove the mold, you must test the weld to make sure it is secured to the pipeline. Strike the top and sides of the weld with a welder s hammer (or appropriate tool) to secure the weld and to test the strength of connection. When using the hammer, some debris might come off; remove the weld slag from the welded area with a wire brush. Give the CP lead a firm tug. If it doesn t come off, the structure is secure. If weld does not hold, remove the scrap weld material, clean, and repeat the weld process. Lastly, test for soundness and electrical continuity. Knowledge Describe final steps associated with CP lead installation. Page 5 of 8 Copyright 2018 Veriforce, LLC. All rights reserved. 08/02/2018

6 Once the weld is secured, some pipeline operators may require the use of weld caps. Weld caps are applied by removing the backing from the cap and firmly placing the cap on top of the weld. Refer to your specific pipeline operator for applicable procedures. Next, repair coating in welded area with a protective coating material, such as petrolatum-based mastic or wax. This material must be compatible with the pipe s coating and the insulation on the wire. Next, ensure CP leads are not damaged during backfill. Make sure to provide enough looping or slack so backfilling will not overly stress or break the lead. Install a cathodic protection test station. Cathodically protected pipelines are equipped with these stations where pipe-to soil potential readings are taken. The type and location of the test station will be specified by the pipeline operator s requirements. Terminate the test lead wires inside the test station using proper sized crimp type connectors on the wire ends. Connect each wire to the terminal, maintaining some slack in each wire at the test station. Coil any slack wire inside the test station. Lastly, take a pipe-to-soil reading using a reference cell (electrode) along with proper testing equipment, if qualified to do so. Such readings are analyzed to determine if the proper amount of protection is being provided. As mentioned previously, the procedure of installing CP leads using exothermic welding demonstrated in this module is only a basic example. When performing this task in the field, be sure to wear appropriate PPE and follow your specific pipeline operator s requirements at all times. Abnormal Operating Conditions (AOCs) Candidates are required to possess the ability to RECOGNIZE and REACT to the listed AOCs for each task. Be prepared to answer questions concerning additional AOCs that may be relevant. Evaluators may ask questions about AOCs throughout the evaluation. An AOC is defined in 49 CFR and as: A condition identified by the pipeline operator that may indicate a malfunction of a component or deviation from normal operations that may: Indicate a condition exceeding design limits; or Result in a hazard(s) to persons, property, or the environment. Recognize: AOC An unintentional release, vapors, or hazardous atmosphere are abnormal operating conditions. Examples could include, but are not limited to: Blowing gas Puddles Dead vegetation Vapors from casing vents Page 6 of 8 Copyright 2018 Veriforce, LLC. All rights reserved. 08/02/2018

7 React/Respond: Proper reactions/responses to take in the event of an unintentional release, vapors, or hazardous atmosphere include the following: Eliminate potential ignition sources. Move to a safe location. Notify emergency response personnel, as appropriate. Limit access to location, as necessary. Follow appropriate procedures for notification, documentation, and remedial action. Recognize: Material defects, anomalies, or physical damage of pipe or a component that have impaired or are likely to impair the serviceability of the pipeline are abnormal operating conditions. Examples could include, but are not limited to: AOC Corrosion/pitting Dents Gouges React/Respond: Proper reactions/responses to take in the event of material defects, anomalies, or physical damage of pipe or a component that have impaired or are likely to impair the serviceability of the pipeline include the following: Determine extent, cause, and potential hazard(s) of defect, anomaly, and/or damage. Mark the location so it may be easily located, as appropriate. Follow appropriate procedures for notification, documentation, and remedial action. Recognize: An unintended fire and/or explosion on or near the pipeline is an abnormal operating condition. AOC React/Respond: Proper reactions/responses to take in the event of an unintended fire and/or explosion on or near the pipeline include the following: Move to a safe location. Notify emergency response personnel, as appropriate. Limit access to location, as necessary. Follow appropriate procedures for notification, documentation, and remedial action. Recognize: AOC A failure or malfunction of pipeline component(s) is an abnormal operating condition. Examples could include, but are not limited to: Test lead is moved/breaks loose during backfill Page 7 of 8 Copyright 2018 Veriforce, LLC. All rights reserved. 08/02/2018

8 React/Respond: Proper reactions/responses to take in the event of a failure or malfunction of pipeline component(s) include the following: Determine extent, cause, and potential hazard(s) of failure and/or malfunction. Follow appropriate procedures for notification, documentation, and remedial action. Glossary Cathodic Protection Systems Ultrasonic Devices A system that helps maintain the integrity of the pipeline and other structures. There are two types of CP systems: galvanic and impressed current. Impressed current is generally the most used in the pipeline industry. Devices that measure the remaining pipe wall thickness. They are accurate and reliable, requiring no cutting or sectioning of pipe and/or components. Measurements usually take only a few seconds per point and are displayed as a digital readout. Note: A person must be qualified in order to perform wall thickness measurements. Page 8 of 8 Copyright 2018 Veriforce, LLC. All rights reserved. 08/02/2018