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Slickline wire sizes

Slickline Lengths* Wire size, (in.) Maximum length, ft (approx..) Maximum length, m (approx..) 0.082 70000 27000 0.092 55000 17000 0.108 40000 12000 0.125 35000 11000 0.140 30000 9000 0.150 30000 9000 0.160 25000 7600 * Zapp's materials for slickline wire is supplied in lengths according to the table 55 PRODUCED PER API 9A SPECIFICATIONS Slickline Well measuring lines CARBON STEEL WELL MEASURING WIRE 0.072 0.082 0.092 0.108 0.125 Diameter 13.9 18.0 22.6 31.2 41.8 Approximat Slickline Guidelines. To maximize the life of your CWI GD™-SUPA® slickline follow these guidelines: Confirm the wire is suitable for the expected well conditions. CWI experts can help you determine that. Use a Vernier Calliper to check the wire OD. Use new packing in the stuffing box and change the wire guides if they show signs of excessive. Sizes range from 0.072 to >0.125. Braided Line - multiple strand wire braided to form a single cable that is also non-Conducting. Electric Line (E-Line) - this is a multiple stand wire armor cable around a single insulated electrical conductor wire

Global Slickline Manufacturer GD-SUPA Slicklines CW

Wrapped around a drum on the back of a truck, the slickline is raised and lowered in the well by reeling in and out the wire hydraulically. Wireline Truck Source: IEC Corp. Wireline The rated safe working load (SWL) for a WTI 16 or 20 slickline sheave is 6,000 lbs. (2,720 kg.). The allowable line pull will depend upon the angle the line is deflected. If the sheave is used as a top sheave, it deflects the line 180°, see figure 2. If the sheave is used as a bottom sheave, it deflects the line 90°, see figure 3 slickline; drill line; wire rope; how to read a product code; certificate. api especification q1; certificate of authority to use the official api monogram; iso 9001:2015; warranty; service centers; safety guidelines; contac GD22™ Slickline for Medium Sour Wells. Material grade UNS S32205/UNS S31803 GD22™ Slicklines combine high strength with excellent resistance to corrosion, pitting and stress corrosion in wells with medium concentrations of CO 2, H 2 S and Low Chlorides. Chemical Composition Range Element Min Max Ni 4.5 6.5 Cr 21.1 23.0 Mo 2.5 3.

Slickline, Braided Line, and E- Line - Webster Horsfal

Well Measuring Line. Referred to as well measuring line, wire line, or slickline, this product is a single end wire used for measuring well depths and for lowering measuring devices into a well. At Loos and Company, we produce weld free stainless steel and exotic high nickel/chrome alloy well measuring wire for use in a wide range of environments Hunting manufactures a full range of slickline downhole tools that include rope sockets, stems, jars, running and pulling tools. Basic tool string components are manufacturing to highest quality standards while running and pulling tools are manufactured to the original designs as per OEM agreements with major service companies The Wire line is passed over the sheave wheel and down through a series of packings in the body of the stuffing box. Upper and lower bushings are provided to guide the Wire line through the stack. To contain well pressure, the packing is tightened against the Wire line by means of a manually operated packing nut Hunting Pear Drop Rope Sockets are used to attach wireline to the toolstring and are predominately used with wireline sizes from 0.092 to 0.160* dependant on size

Slickline Global Manufacturer - Central Wir

While spooling slickline wire we have to counting the lenght of wire and record it in a wire record form. In this form contain the all information about slickline wire, i.e : manufactured, type of wire, size of wire, material, lenght of wire, wire testing result, etc Sidewall Cutter. The Sidewall Cutter is used to cut slickline wire against the tubing wall. This may be required to clear the well past the Tubing Retrievable Subsurface Safety Valve (TRSSSV) or to clear down to ball of wire. The device is activated by simple manipulation of the running string or by sitting down on an obstruction 3 Slickline Capabilities.pptx - Slickline Strengths and Capabilities Minimum Breaking Strengths Wireline \u2013 Breaking Strengths(lbs Carbon Steel \u2013 API. S T E M Force D 2 x .7854 = Area Area x Pressure = FORCE Wire Size Area.092.0066.108.0092.125.0123 3/16.0276 D 2 x 8 ÷ 3 = Wt/Ft Stem Size Wt/Ft. Central Wire Industries SUPA 40® Slickline size:0.140 Evaluate this Device. Download Catalog. SUPA 40® is a duplex stainless steel suitable for well conditions with medium concentrations of CO₂, up to 35% with no H₂S present and up to 30% chlorides where H₂S partial pressure is 3% max. The duplex structure of SUPA 40® improves the. Dual Drum Wireline Trucks. WWS custom built dual drum trucks are tailored to deal with extreme conditions. Slick Line sizes range from 0.108- 0.125 - 0.160 Cables, Braided Line and Swab Line 7/32nd cable (High Strength) E-Line 5/16 simultaneous rig ups. Data Acquisition System for Pressure Tests, Line pull, Wellhead Pressure.

Slickline - Patco Completion Service

  1. Slickline Cable/Wireline Cable. A slickline cable used for logging an oil&gas well that has a smooth, round outer surface that allows for a seal to be used to separate the pressure from the well from atmosphere. This contrasts with a wireline cable which typically has two layers of wires stranded around a core which, due to this structure, has.
  2. Slickline looks like a long, smooth, unbraided wire, often shiny, silver/chrome in appearance. It comes in varying lengths, according to the depth of wells in the area it is used (it can be ordered to specification) up to 35,000 feet in length. It is used to lower and raise downhole tools used in oil and gas well maintenance to the appropriate.
  3. Basic Description. Used in slickline operations to confine well fluids and gases to a well. The stuffing box wipes the wire clean. It is available in manual and hydraulic configurations. Available in pressure ratings of up to 15,000 PSI and sizes up to 7. Steps to take if stuffing box is not working. For the manual stuffing box, an.
  4. The BT Wire Retriever may be used when there is a desire to locate and potentially retrieve a broken (parted) slickline or wire. Different size fingered skirts may be interchanged depending on the tubing size

Central Wire Industries GD22™ Slickline size:0

perature, buoyancy, slickline and toolstring fric-tion against the wellbore wall, lift and measuring wheel precision. The variety of sizes and materi-als used for slickline wire may also impact mea-surement readings. The most common slickline wire diameters are 0.092, 0.108 and 0.125 in. [2.34, 2.74 and 3.18 mm]. The materials fro When working in H2S wells, inhibit the wire. When coming out of hole, use the winch relief valve. Always write down the length, OD's and size of fishing necks of the different components you are running in the hole. When cutting wire at surface (rig down) make sure that neither end can fly. Always work in sight of each other TTC have developed a Slickline Operations Training Manual which is now in its 5th reprint. It is used as courses support and has been widely accepted as a reference book for slickline. Based on the successful 3 editions of the original TTC Wireline Operations Training Manual this rewritten and updated manual is an essential slickline. Mobile Units. We have 7 slickline truck units with wire sizes ranging from .125 to .160

WSG Slickline Services are based on using a wide range of line sizes, which includes 0.108 /0.125/0.140/0.160 wire always resistant as standard for Co2/H2S; Each Unit is supplied with a fully stocked standard tool container ensuring we have all of the required tools for a successful operation, the container includes The Slick-E-Line® system combines the versatility and efficiency of traditional slickline with the real-time digital data streaming capability of electric line. Leveraging decades of experience, the cutting-edge Slick-E-Line® technology is bridging the gap between cased-hole electric line and slickline services and supports all parties with.

Taylormade TC, Technical Referance | Wireline, Slickline

How Do Wirelines and Slicklines Work? Rigzon

Slickline and Braided Cable Spooling Tensions (appendix A) Scenarios Considered This Best Practice covers the following spooling scenarios 1) Spooling off an out of service Slickline wire from a Slickline unit onto a transport drum (wire for storage or disposal due too many in service hours, failure in service or too short for operations Available in single- or double-drum configurations and for wire sizes from 0.092 to ¼ in. (including .160-in. slickline), this wireline winch unit model comes standard with 72-HP or optional 109-HP heavy-duty power pack

Primary well control system for wireline operations is depended on type and size of line and is located above the secondary well control system. The following systems are used: • Slickline operations - Stuffing box for solid wireline • 3/16, 7/32 and 5/16 cable - Grease injection head with relevant sized flowtube The cable comes in different sizes such as 0.092, 0.108, 0.125'', 3 /16 for different forms of operation. A drum is made to rotate at a time by the control of the levers from the control cabin. The wire is stored on a drum located in front of the operator on the winch unit Slickline and Wireline Interventions. While slickline is a well-accepted technique for maintaining production on target and keeping opex within budget, the LIVE digital slickline and OPTICall thermal profile and investigation services significantly expand the scope of work that can be efficiently and economically conducted on slickline 1-5 Slickline Training Manual / Introduction 1-5 wellbores increased in depth, a winding handle with a gear ratio was added to pull up the greater weight. By this time, a brake hand was added to the other side of the drum to control the speed of the line going in the hole. The principal power source at this time was steam and a steam operated engine was used to pull the line out of the hole

AnaLog's Cable (Electric Wireline) Properties Table

EMC CABLES, SLICKLINES, Wirelines Cable

  1. The slickline is a high quality length of wire which can be made from a variety of materials, (from mild steel to alloy steel) and typically comes in three sizes: 0.092; 0.108; and 0.125 inches in diameter. For larger sizes, a braided wire construction is utilized which is typically 3/16 or 7/32
  2. um and stainless steel structural components, and a simple side loading system that provides easy line placement. Incorporation of cable shrouds above the wheel prevents the line from jumping sheave.
  3. WIRELINE TOOLS. Relentless customer focus is at the forefront of our service support philosophy. We understand the operational constraints of our customers. We understand the wells our clients develop, the wells they service and the sometimes harsh conditions they impose. We understand the deployment mediums and their limitations
  4. Spool type D mm d mm d1 mm L mm I mm Wire size mm Ø Normal net weight, kg; DIN 50: 50: 32: 11: 50: 38: 0.015 - 0.04: 0.10: DIN 63: 63: 40: 11: 63: 49: 0.015 - 0.04.

Slicklines Made for Harsh Well Conditions, Weld-Free CW

Calculations OD2 x 8 3 SIZE AND CROSS SECTION AREA Cross Section Area 0.0037 0.0053 0.0066 0.0092 0.0123 0.027 0.037 0.049 0.077 Wire Size 0.072 0.082 0.092 0.108 0.125 3/16 7/32 1/4 5/16 WirelineOperations-SlicklineCalculations WIRELINE OPERATIONS: SLICKLINE CALCULATION The information calculated by this software is purely advisory in nature. in this document. Enter old cable diameter and length of full drum in yellow cells. Enter diameter of new cable in red cell. length of a full drum of new cable size is diaplayed in white cell. Enter appropriate data into white blocks The main torque body comes in 1 1/2-in, 1 7/8-in and, 2 1/2-in sizes and has several different show sizes that can be easily changed on the main body of the tool as the scale is broken down. The debris is recovered by subsequent bailer runs. Applications . To break up persistent sand/scale concretions which have resisted recovery by other methods

offering for Slickline includes the full suite of down hole tools and sizes to perform all standard and special project operations. We offer 5,000# - 10,000# psi rated pressure control equipment with a complete line of standard Slickline line/cables to the exotic alloy line/cables for working in high concentrations of Co2 and H2 - Finding the top of the wire, selecting the correct wireline grab size and type. - Running the grab to 'pick up' the wire without 'balling' the wire, bringing the wire to the surface. Day 2 - Safe handling of potentially multiple strands of wire above the BOP. - Recovering strands until a single strand is left The DOLPHIN Slickline Measuring Device is a heavy duty two wheeled device which accurately measures both wireline depth and tension. It minimizes wire abrasion and fatigue by Changes in wire size are accounted for by the panel software. Wire stretch can also be automatically calculated by the panel. The panel operates on 12v and. The ACT Releasable Rope Socket is designed to release in the event when a wirline / slickline toolstring cannot be recovered from the wellbore. The trigger device is activated by a drop bar, which is dropped down the wire in a similar manner to a Go-Devil or wireline snipper. When the drop bar contacts the release trigger, the collet releases.

Wireline Equipment & Slickline Tool

  1. um and stainless steel structural components, and a patented top loading system that allows for easy line placement and prevents the line from jumping sheave
  2. 1. n. [Well Workover and Intervention] A type of multistrand wireline used for slickline applications in which higher tension or weight-carrying ability is required. The most common size of braided line is 3/16-in diameter, although special heavy applications use 1/4-in and 5/16-in sizes
  3. The Slickline Measuring Head : The Slickline measuring head is a heavy duty wrap around device used for measuring Slickline depth (Feet / Metric). Measuring head supports Slickline Wireline sizes from 0.092 to 0.125 & 3/16 by changing wheel type. 8″ & 16 Measuring wheel comes in metric or imperial measuring units
  4. slickline rope socket The LiMAR Slickline Rope Socket is devised to effectively attach the end of the slickline to a wireline toolstring. A pear drop & sleeve assembly provides and maintains a reliable grip to the wire especially when under load during heavy jarring operations
  5. slickline tools. The disc and spring rope socket is one of the wireline basic tools for the oilfield wireline and slickline operation, the rope socket in disc and spring type is used to attach wireline to the tools string. In the wireline operation, the disc and spring rope socket is firmly connected to the steel wire and the tool string by the.
  6. um and stainless steel structural components, and a simple side loading system that provides easy line placement. Incorporation of cable shrouds above the wheel prevents the line from jumping sheave. (2) units available

This article is about measuring device for slickline operation in oil and gas industry. Measuring device placed on slickline winch unit. One of important accessories that should be used when performing any type of wireline / slickline work, whether it is a simple depth measurement, a delicate logging, survey or the setting or retrieving of a special tool, is the measuring device Slickline looks like a long, smooth, unbraided wire, often shiny, silver/chrome in appearance. It comes in varying lengths, according to the depth of wells in the area it is used up to 35,000 feet in length. It is used to lower and raise downhole tools used in oil and gas well maintenance to the appropriate depth of the drilled well

Well Measuring Line - Loos & Co

Available for all slickline wire sizes Available in 5,000, 10,000 & 15,000 psi working pressure. Available with any Combination of Quick Unions. Available in H2S & Standard service. Customizable to meet customer requirement. Technical details for equipment ordering: Bottom Connection, wire size, Sheave Wheel size details Brookfield Wire is a leading supplier of cold drawn stainless steel, nickel, and nickel alloy wire. Our stainless steel and nickel alloy products are manufactured to the highest industry standards in a broad range of chemistries, sizes, tempers, and finishes. In addition to the standard products outlined below, we produce special products. Jun 18, 2021 (The Expresswire) -- Global Slickline Services Market Report organizes across the globe into distinct portion based on industry standards. It.. The key factor in slickline is that it can be performed under 'live' well conditions. Equipment required to conduct slickline operations normally consist of: Alloy or Stainless Steel wireline (piano wire) normally sized 108 diameter or 0.125 diameter; Winch unit capable of holding 25000ft of wire; Diesel or Electric power pack; Well Control Pane

Hunting Energy Services Slickline Tool

  1. Hydraulic Slickline Trucks. Full size units. Quick-Rig units. Full suite of tools for each unit. Gauge rings, bailers, fishing tools, broaching tools, etc. Slickline: 0.092 to 0.160 OD. Braided-Line: 3/16, 7/32 and 5/16 OD. Grease Injection equipment. Special alloy wire for H2S/corrosive environments
  2. Size (inch) Diameter (mm) . Min Breaking Strength (lbf ) Min Tensile Strength (N/mm2) WT/ft (lbs) Pren. 0.092 2.34 1421 1470 0.02
  3. Available in a range of sizes and with all major types of connection, these our jars are an essential addition to any slickline operation. The Blockbuster is designed to provide extra-high impact for ultra-demanding slickline operations, including heavy duty fishing, with solid or braided wirelines; delivering over 25,000 lb of impact force

Wireline Product

16/20 Composite Slickline Floor Sheave. The Wireline Technologies, Inc. 16 and 20 Slickline Sheave feature a lightweight composite wheel, high strength aluminum and stainless steel structural components, and a simple side loading system that provides easy line placement. Incorporation of cable shrouds above the wheel prevents the line from. Slickline refers to a single strand wire which is used to run tools into wellbore for several purposes. It is used in the oil and gas industry, but also describes that niche of the industry that involves using a slickline truck or doing a slickline job. Slickline looks like a long, smooth, unbraided wire, often shiny, silver/chrome in appearance 1-800-338-0308 A-3 B MANDREL ASSEMBLY 1 1/2 1 3/4 2 2 1/2 Part Number 10BM0150 10BM0175 10BM0200 10BM0250 COMPONENTS Mandrel 10B00196 10B00196 10B00204 10B0022 Two chassis sizes (2.200 and 3.600 OD) Gauge hanger can be set in a range of tubing sizes (4 1/2 - 9 5/8) Slickline deployed. Allows one Hi-Ex assembly to be used in various tubing/casing sizes. Run using the Bonnetts QC Trigger. Recoverable with industry standard pulling tools. Simple, robust design Integrity Slickline offers various types of wire and capabilities for your fishing and swabbing needs depending on the location. Now available in the Northeast region. . SPECIALIZED FISHING OPERATIONS. Perforator Guns. Plungers, Bottom-hole assemblies, Rabbits, and broken plunger-lift related items. Request Info

The ACT Wire Finder is used during wireline fishing operations to locate the top of a broken wireline and retrieve it from the well bore. The fingers of the wireline retriever press against the tubing wall and locate the top of the broken wireline, and direct it up inside the finder The nickel alloy slickline in .108 inch and .125 inch are ideal for hydrogen sulfide and carbon dioxide environments. When additional strength is needed for larger heavy-duty fishing operations, the Dycam® braided lines, available in 0.1875 inch and 0.25 inch provide the required weight and durability for the job. Bailing Sand and Debris would determine that you need to choose an alloy wire or seek to protect/inhibit your wire. (Alloy wire is by far the safest option.) To determine the Partial Pressure for CO 2: pC0 2 = CO 2 % X BHP/100 Example: In a well with 3% CO 2 and a BHP of 2,000psi pCO 2 = 3(%) x 2000/100 pCO 2 = 3(%) x 20 pCO 2 = 60psi Under NACE regulations a pCO2 of. Wireline Product In addition, our slickline is manufactured from alloys designed to provide a continuous 30,000 feet (9,144 m) weld-free, bright-finish wireline. • Confirm the wire is suitable for the expected well conditions. CWI experts can help you determine that. • Use a Vernier Caliper to check the wire OD

Timmy joined the Cardinal Slickline team in 2013 and is responsible for equipment maintenance, job loadouts, and managing the support staff. Cardinal Services, based in New Iberia, LA, is a leading oilfield service company specializing in land and offshore well intervention services ZIL carries out Slickline Services with the following equipment; 55HP Hydraulic-driven single unit with 22,000 ft. of .108 regular Slickline plus complete set of wire-line tools. 70HP Hydraulic-driven double drum unit with 22,000 ft. of 0.108 Slickline and 20,000 ft. of 3/16 cable plus complete set of wirelin

Slickline, Braided Line, and E- Line - Webster Horsfall

Hunting Energy Services Rope Socket Pear Drop Typ

The global slickline services (SLS) market was valued at USD 8.71 billion in 2020 and is predicted to grow at a compound annual rate of 2.4% from 2020 to 2025. Escalating oil production and aging reservoirs are important factors in the industry for slickline services. Slickline refers to a single stranded wire or cable that is thrown down a. The Slickline measuring head is a heavy duty wrap around device used for measuring Slickline depth (Feet / Metric). Measuring head supports Slickline Wireline sizes from 0.092 to 0.125 & braided line 3/16 by changing wheel type according to type of Wireline. It is mounted to the heavy duty spooler assembly with, screw down adjustable. Wireline is a general term used to describe the use of a multi-conductor, single conductor or slickline cable, or wireline for intervention in oil or gas wells. Wireline cabling is used to aid in pipe recovery duties, well intervention, and evaluation tasks. As a way to bring effective action, wire-line services are used in a multitude of.

Slickline - Wikipedi

WIRELINE EQUIPMENT ADDITIONAL WIRELINE EQUIPMENT SOLUTIONS 2' & 3' Measure Head Frame Assemblies Rim and Hub Center Section Assemblies: E-Line (3/16, 7/32, 1/4, 9. Geo-Log Slickline Head The Geo-Log Slickline Measure Head is a state of the art device designed for measuring slickline wire in ranges of .092 to .187. The device opens, or separates by releasing 4 positive locking tabs to allow for quick loading of the line, therefore making it possible to change line sizes in a matter of minutes. The three wheels are each dedicated to the individual. Integrated mast, tandem axle, large unit with two drum packages one of which is a split drum which means the truck has three wire intervention options; 2 slick lines varying in size for different applications and a braided line for swabbing & fishing services. These units are a rolling shop with all tools on board and the versatility to cover. Slickline is a smooth single strand of wireline with diameters ranging form 0.082 to 1.25. Slickline has no conductor (although there are specialized polymer coated slicklines and tubing encapsulated (TEC) slicklines). They are used for light well construction and well maintenance activities as well as memory reliant subsurface data gathering

Petropedia - What is Slickline? - Definition from Petropedi

Slickline Rope Socket. Designed to attach the wireline to the toolstring, the Slickline Rope Socket incorporates a robust Sleeve feature which is designed to maintain form and ensure continuous performance. Should the Rope Socket and toolstring be left in the well due to any unforeseen circumstances and the wire has been recovered, the HD FRC. On the Double Drum Frame cables for slickline and braided services can be combined in several ways. All popular cable sizes can be used. With our optional lower split drum, the Double Drum Frame holds 10,000 m of each 0.160″ and 7/32″ on lower drum with 5/16″ Dyform on upper drum Download. Slickline. Alan Goodridge. costly 'fishing' job. Due to downhole tools getting stuck because of malfunctions or 'downhole conditions' including sand, scale, salt, asphaltenes, and other well byproducts settling or loosening off the pipe walls because of agitation either by the downhole tools or a change in downhole inflow, sometimes.

Wire Rope Clips | Assembly Specialty Products

Precision steel for the oil & gas industry Zap

The iWinch Skid System for international markets is packaged in an 6.5ft wide container. This is ideal for compact offshore wireline systems, for onshore wireline systems that are hauled to site on a flatbed trailer or similar. The system is divided in a winch area and an operator area divided by in internal window LONDON--(BUSINESS WIRE)--The global slickline services market is poised to grow by USD 943.28 million during 2020-2024, progressing at a CAGR of over 5% during the forecast period.Request free. bare wire .082 thru .188. Line Wiper Assembly. 2131-A00. For .066 thru .108 Slickline. Weight Indicator. Pounds Kilograms. 0 to 2000 0 to 1000 . 0 to 4000 0 to 2000. 0 to 6000 0 to 3000. 0 to 10000 0 to 5000. Load Cells. Tension-type Compression-type. Millennium Wireline.

How to Spooling Slickline Wire - IndustriMigas #1 Oil

Does any one know the calculation to determine a fallback per 1000' for Slickline wires - example 0.125 wire - 2.875 Pipe size- fall back ? Please note i have the charts, three actually with different results in each, but the calculation is missing for each chart, not sure which to go by here so i figured best to find a formula Other Wire Products. In addition to the above, PEIME also supply Braided Cables, Carbon Steel Slickline Wires and Flat and Shaped Wires. Local Stock. For convenience of our regional customers, we keep fast moving sizes and grades of wire in stock in Jebel Ali Free Zone. Kindly find more information about available grades, sizes and lengths here Global Slickline Services Market. The slickline is defined as single strand wire or cable which launched into a well to deliver or retrieve downhole hardware. The slickline services include various operations such as Well Completion, Well Intervention, and Logging

EMC CABLES, Certificate, Wirelines CablesHow to Spooling Slickline Wire | Seputar KerjaWireline drill rods, diamond drill rods, drill rods BQ NQWire Retriever – PetroSAC

A cable (10) for use in the deployment of services in a wellbore as described which comprises a conductive core (12) which is insulated from at least one layer (18, 20) of armour wires by an insulating layer (16). To control the migration of well fluids through the pressure control equipment, the voids (24) between the armour wires (22) are filled with a resilient material to prevent well. Our subsurface flow control equipment is well suited for all applications, including high-pressure, high-volume large bore completions and extreme temperature environments. SRH Plug. Uses the top no-go location and holds pressure from above and below by key/nipple engagement. V0-qualified for high-pressure and high-temperature environments WOM has developed 7-3/8-10K Wireline Cutting Valve based on gate valve concept to cut and seal wireline/Slickline. The wireline cutting valve is equipment with hydraulically actuated gate made to shear and seal wireline/slickline of a given specification in the wellbore Abstract. A Slickline wire failed after nearly 400 h of service. In order to find out the main causes and the sequence of this failure, a detailed analysis was carried out on a fracture fragment of this component. This analysis revealed that the operation of the wire produced a series of superficial discontinuities, comprising corrosion pits.