API 6A Standard Pdf : Specification for Wellhead and Christmas Tree Equipment

In the oil and gas industry, standards play a crucial role in ensuring equipment safety, reliability, and efficiency. Among these, the API 6A standard, developed by the American Petroleum Institute, stands as a foundational guideline specifically focused on wellhead and Christmas tree equipment. Wellheads and Christmas trees are critical components in oil and gas extraction, as they provide the necessary control over high-pressure zones and fluid flow from oil wells.

API 6A outlines stringent requirements for the design, material selection, manufacturing, and testing of wellhead and Christmas tree equipment, aiming to prevent operational failures and enhance safety. Compliance with API 6A ensures that equipment can withstand the extreme conditions often encountered in oil and gas exploration and production. This article delves into the essential aspects of API 6A, covering its specifications, updates, certification processes, and the benefits of adherence to this vital industry standard. Whether you’re in manufacturing, operations, or regulatory compliance, understanding API 6A is key to maintaining the highest standards in oil and gas operations.

API 6A standards are a set of guidelines developed by the American Petroleum Institute (API) specifically for the design, material selection, manufacture, and testing of wellhead and Christmas tree equipment used in the oil and gas industry. These standards ensure that such equipment can handle the high pressures, temperatures, and challenging conditions found in drilling and production operations. The primary aim of API 6A is to maintain safety, reliability, and efficiency in oil and gas extraction by setting stringent requirements for essential components that control and manage well pressure and flow.

Key Aspects of API 6A Standards:

1. Equipment Specifications
   API 6A covers specifications for wellhead and Christmas tree components, including casing heads, tubing heads, spools, adapters, connectors, and valve assemblies. Each of these components must meet defined quality and performance standards to ensure operational safety and efficiency.
2. Material Requirements
   The standard dictates strict requirements for material properties to ensure durability and corrosion resistance. Materials must meet minimum thresholds for strength and withstand harsh environmental conditions, such as corrosive gases and extreme pressures and temperatures.
3. Pressure and Temperature Ratings
   API 6A classifies equipment according to pressure and temperature ranges, which helps operators select equipment suitable for various drilling and production conditions. Ratings ensure that equipment can withstand the pressures encountered in deep wells or high-temperature drilling environments.
4. Testing and Quality Control
   API 6A mandates rigorous testing procedures to verify the integrity of each component. Testing includes pressure testing, thermal cycling, and material verification to confirm equipment performance under operational stress. Manufacturers must maintain quality control systems to ensure consistent compliance with API 6A.
5. Design and Manufacturing Standards
   API 6A provides detailed guidelines on the design and manufacturing processes for wellhead and Christmas tree equipment. These standards cover design tolerances, welding specifications, and assembly methods to ensure robust construction and fit.
6. Traceability and Documentation
   The standard requires complete traceability of materials and components used in manufacturing, including documentation that certifies compliance with API 6A specifications. This traceability is critical for audits and ensuring that each part of the equipment meets required standards.
7. Certification and Compliance
   Compliance with API 6A is often verified by third-party inspection and certification bodies. Certification signifies that equipment meets the API’s high standards for safety and performance, which is crucial for its acceptance in international oil and gas operations.

By setting these comprehensive standards, API 6A helps prevent equipment failure and accidents, minimizing environmental risks and improving operational reliability.

Here’s a detailed look at the key components and specifications of API 6A, which cover the critical aspects of wellhead and Christmas tree equipment used in oil and gas operations:

1. Wellhead Equipment

• Casing Heads: The casing head is the first component installed on the surface casing of the well. It provides support for subsequent casing strings and houses the primary seal against external pressure. API 6A specifies the minimum design requirements and pressure ratings for casing heads to ensure secure connections and durability.
• Tubing Heads and Hangers: Tubing heads support the tubing string and maintain a pressure-tight connection. API 6A outlines specifications for tubing heads, including pressure ratings, sealing mechanisms, and load-bearing capabilities, to ensure they withstand operational stresses.
• Spools: Spools connect different sections of casing or tubing, allowing for flexible pressure control and fluid flow management. The standard dictates pressure and temperature ratings for spools to match the conditions they will encounter in the well.

2. Christmas Trees

• Valves: API 6A includes specifications for various types of valves used in Christmas tree assemblies, including gate, check, and choke valves. These valves control the flow of oil and gas, and API 6A standards ensure they are designed to handle high pressures and provide leak-proof operation.
• Spools and Fittings: These components connect the Christmas tree equipment with the wellhead. They must meet the required pressure ratings and material standards to prevent leakage and ensure stable connections.
• Chokes: Chokes regulate the flow rate of oil or gas from the well. API 6A outlines requirements for both adjustable and fixed chokes, specifying material standards, pressure tolerances, and wear resistance to ensure reliability.

3. Connectors and Flanges

• Connectors: Connectors link various wellhead and Christmas tree components, ensuring a secure and pressure-tight fit. API 6A provides standards for connector design, such as bolt patterns, dimensions, and sealing capabilities, to maintain integrity in high-pressure environments.
• Flanges: Flanges are standardized in API 6A to ensure compatibility across different components. The standard specifies dimensions, pressure ratings, and materials for flanges used in wellhead assemblies to ensure a uniform connection system that is both durable and easy to install.

4. Material Requirements

• API 6A specifies the materials used in wellhead and Christmas tree equipment to ensure they can withstand corrosive substances, high pressure, and extreme temperatures. Requirements cover minimum yield strength, impact resistance, and corrosion resistance, often mandating stainless steel or specialized alloys for these applications.
• The standard also includes provisions for material traceability, requiring manufacturers to document the material origin and certification to ensure compliance with API 6A specifications.

5. Pressure and Temperature Ratings

• API 6A classifies equipment into pressure classes ranging from low-pressure to ultra-high-pressure ratings. These classes ensure equipment compatibility with well conditions, preventing failures that could occur if the equipment were misclassified.
• Similarly, API 6A defines temperature ranges that equipment must be able to handle, such as the “K” (-75 to 250°F) or “X” (-20 to 650°F) ranges, ensuring they can withstand conditions from freezing to extreme heat.

6. Testing and Quality Assurance

• Pressure Testing: API 6A requires equipment to undergo pressure testing at specific intervals and conditions to verify their integrity under high-pressure scenarios. Testing often includes hydrostatic and pneumatic pressure tests.
• Material Verification: Each component must undergo rigorous material testing, including chemical composition and mechanical property verification, to ensure compliance with API 6A material standards.
• Non-Destructive Testing (NDT): NDT methods such as ultrasonic testing or radiography are often required to detect internal flaws in the components, preventing undetected faults that could lead to failure.

7. Design and Manufacturing Standards

• Design Specifications: API 6A dictates detailed design parameters, including dimensional tolerances, allowable stress, and load requirements, to ensure consistent quality and fit.
• Welding and Assembly: API 6A provides specific guidelines for welding procedures and assembly methods, ensuring that manufacturing processes do not compromise equipment integrity.
• Corrosion and Surface Treatments: Requirements for coatings or treatments to resist corrosion and abrasion are included in API 6A, prolonging equipment life and performance in harsh environments.

8. Traceability and Documentation

• API 6A mandates traceability for all components, requiring manufacturers to document material sources, batch numbers, and production details. This documentation aids in quality control and facilitates audits, helping operators confirm that all equipment meets API standards.

By adhering to these comprehensive specifications, API 6A ensures that wellhead and Christmas tree equipment can safely and effectively handle the challenging conditions of oil and gas operations, minimizing the risk of failure and enhancing operational efficiency.

The design and manufacturing standards outlined in API 6A provide a detailed framework to ensure that wellhead and Christmas tree equipment are built to withstand the demanding conditions of oil and gas operations. These standards help maintain equipment reliability, safety, and longevity under high-pressure, high-temperature (HPHT) environments. Here are the main aspects of the design and manufacturing standards in API 6A:

1. Design Specifications

• Dimensional Tolerances: API 6A sets precise tolerances for each component’s dimensions, ensuring that parts fit together seamlessly and are compatible with other equipment in the wellhead and Christmas tree assemblies.
• Stress and Load Requirements: The standard provides guidelines for allowable stress and load limits based on the operational conditions. This ensures that equipment can withstand the pressures and stresses encountered in real-world applications without failure.
• Pressure Ratings and Classifications: API 6A assigns pressure ratings to equipment based on design criteria, ensuring that components can safely contain well pressures, especially in deep and ultra-deep wells.
• Temperature Ratings: API 6A includes temperature classifications, requiring equipment to be designed for specific temperature ranges to prevent material degradation in extreme hot or cold environments.

2. Welding and Assembly Requirements

• Welding Specifications: API 6A includes stringent requirements for welding procedures, including the types of welding materials, techniques, and heat treatments allowed. Welding operators must be certified, and all welding processes are closely monitored to ensure strong, defect-free joints.
• Post-Weld Heat Treatment (PWHT): For certain high-stress components, API 6A mandates post-weld heat treatment to relieve stresses and improve material toughness, especially for high-pressure applications.
• Non-Destructive Testing of Welds: All welds undergo non-destructive testing (NDT) methods, such as ultrasonic testing, radiography, or magnetic particle inspection, to detect potential flaws or weaknesses before the equipment is deployed.

3. Material and Component Traceability

• Traceability Requirements: Each component in API 6A-compliant equipment must have full traceability, allowing operators to track the material’s origin, batch, and production history. This traceability ensures compliance with material standards and aids in quality assurance.
• Marking and Identification: API 6A requires that each component be permanently marked with identifying information, such as manufacturer, pressure rating, temperature rating, material class, and unique serial numbers. These markings are essential for maintenance and inspections.

4. Corrosion Resistance and Surface Treatments

• Material Selection: Materials used in API 6A equipment must resist corrosion, hydrogen embrittlement, and sulfide stress cracking, especially when operating in sour gas or corrosive environments. API 6A specifies materials, such as high-strength steel alloys, stainless steel, and corrosion-resistant alloys (CRA), to meet these requirements.
• Surface Coatings and Treatments: API 6A mandates specific coatings, such as anti-corrosive and anti-abrasive layers, to protect equipment surfaces from wear and corrosion. These coatings prolong the equipment’s life and maintain its structural integrity.

5. Quality Control and Testing

• Routine Inspections and Testing: API 6A requires ongoing quality control and routine testing throughout the manufacturing process, including material verification, pressure tests, and mechanical tests. Components that fail to meet standards are rejected to ensure only quality-compliant products reach the field.
• Non-Destructive Testing (NDT): Besides testing welds, API 6A requires NDT methods on all critical components to detect cracks, inclusions, or other defects without damaging the part. This testing might include radiography, ultrasonic testing, and dye penetrant inspection.
• Pressure Testing: API 6A mandates hydrostatic and pneumatic pressure testing to verify that each component meets the specified pressure rating. This testing simulates field conditions, ensuring the equipment can handle real-world pressures without leaks or deformation.

6. Manufacturing Process Controls

• Documentation and Record Keeping: All stages of manufacturing, from material selection to final assembly, must be documented, and manufacturers must maintain records for each step. This ensures that each component can be traced back through its production history, providing quality assurance.
• Third-Party Inspection and Certification: Many API 6A components undergo third-party inspections to verify compliance. Certification by independent inspectors provides an additional level of quality assurance, affirming that equipment meets API 6A standards.

7. Maintenance of Equipment Standards

• Ongoing Standards Compliance: Manufacturers are expected to keep up-to-date with any revisions or updates to API 6A standards and incorporate those changes into their design and manufacturing processes.
• Training and Certification for Personnel: Personnel involved in the design, welding, testing, and assembly of API 6A components must be qualified and periodically trained to ensure they adhere to the latest standards.

By adhering to these stringent design and manufacturing standards, API 6A ensures that wellhead and Christmas tree equipment used in oil and gas operations are both safe and reliable. These standards prevent equipment failures, enhance operational safety, and promote efficiency, especially under challenging HPHT conditions.

Certification and compliance with API 6A are essential for ensuring that wellhead and Christmas tree equipment meets the rigorous safety, reliability, and performance standards needed for oil and gas operations. Achieving API 6A certification demonstrates a manufacturer’s commitment to producing quality equipment that can safely operate under extreme conditions. Here’s an overview of the certification and compliance process for API 6A:

1. API Monogram Program

• Monogram License: The API Monogram Program is a voluntary licensing program that allows manufacturers to mark their products with the API monogram, signifying that they meet API 6A requirements. To obtain this license, manufacturers must pass an audit by the API and demonstrate compliance with all API 6A standards.
• Quality Management System (QMS): A prerequisite for the API monogram is that manufacturers must have a QMS that complies with API Q1 (Specification for Quality Management System Requirements for Manufacturing Organizations for the Petroleum and Natural Gas Industry). This ensures systematic control over processes and consistent product quality.

2. Third-Party Inspection and Testing

• Independent Testing: In addition to in-house testing, API 6A-compliant equipment often undergoes third-party inspection and testing to verify that it meets the standard’s specifications. This external validation enhances credibility and confirms that products can reliably perform under high-pressure and high-temperature conditions.
• Pressure and Material Testing: External testing typically includes pressure and material verification to ensure that the equipment meets all specified tolerances and ratings. Testing agencies issue certificates for compliant products, which are essential for demonstrating adherence to API 6A.

3. Product Specification Levels (PSL) Compliance

• PSL Classifications: API 6A defines different Product Specification Levels (PSLs) based on the complexity and safety requirements of the equipment. PSLs range from PSL 1 (basic) to PSL 4 (most stringent), with each level requiring specific design, material, and testing standards. Certification to a specific PSL verifies that equipment meets the necessary criteria for its intended application.
• PSL Documentation: Manufacturers must document compliance with the relevant PSL in equipment manuals and certificates. This documentation is crucial for operators to verify that the equipment is suitable for particular operational conditions.

4. Documentation and Traceability

• Complete Traceability: API 6A requires full traceability of all materials and components, from raw materials to finished products. This ensures that each component can be traced back to its origin, aiding in quality control and compliance verification.
• Documentation Control: Manufacturers must maintain a detailed record of their compliance procedures, test results, and material certifications. These records are subject to audits and must be accessible for inspection upon request.

5. Marking and Labeling Requirements

• Product Marking: API 6A specifies labeling requirements for compliant products, including pressure rating, temperature range, material class, and PSL. Markings ensure that operators can easily identify equipment specifications and verify its suitability for their operational needs.
• API Monogram Marking: Licensed products bear the API monogram, signifying compliance with API standards. This monogram assures customers and regulatory agencies that the equipment meets recognized industry standards.

6. Audits and Recertification

• Regular Audits: To retain API 6A certification, manufacturers undergo periodic audits to ensure ongoing compliance with the standard. These audits review manufacturing processes, quality management practices, and documentation.
• Recertification: Certification must be renewed periodically, often every three years, to maintain compliance with API 6A. The recertification process includes a review of all relevant documentation, testing records, and any updates to ensure that the product continues to meet the latest version of API 6A.

7. Importance of Certification for International Acceptance

• Global Recognition: API 6A certification is internationally recognized, enabling manufacturers to distribute their products worldwide. Compliance with API standards is often a prerequisite for equipment acceptance in global markets, as it demonstrates a high level of quality and reliability.
• Reduced Risk and Liability: Certified equipment reduces the risk of operational failures, environmental hazards, and accidents. For operators, using API 6A-certified equipment minimizes liability and ensures adherence to industry best practices.

8. Compliance for End Users and Operators

• Verifying Equipment Certification: Operators are responsible for ensuring that purchased equipment is certified to API 6A and meets the necessary PSL and material requirements. Verifying certification helps operators maintain safety and performance standards in the field.
• Maintenance and Inspections: Operators must conduct regular maintenance and inspections of API 6A equipment to ensure continued compliance. This includes checking for wear and damage that could compromise equipment performance and certification validity.

Adhering to API 6A certification and compliance processes ensures that equipment used in oil and gas operations meets rigorous safety and performance standards, reducing the risk of failure and enhancing operational reliability.

API 6A compliance offers numerous benefits, especially in the oil and gas industry, where safety, reliability, and performance are paramount. Complying with this standard helps ensure that wellhead and Christmas tree equipment can withstand extreme conditions, minimize risks, and maintain operational efficiency. Here are the key benefits of API 6A compliance:

1. Enhanced Safety

• Risk Mitigation: API 6A compliance helps reduce the risk of equipment failure, which is crucial in high-pressure, high-temperature (HPHT) environments where the consequences of a failure could be catastrophic.
• Protection of Personnel and Environment: By ensuring equipment meets high safety standards, API 6A minimizes potential hazards to workers and prevents environmental incidents, such as oil spills or gas leaks.
• Standardized Safety Features: API 6A-compliant equipment incorporates essential safety features, including pressure and temperature ratings, reliable sealing mechanisms, and material durability, ensuring safe operation under extreme conditions.

2. Improved Equipment Reliability and Performance

• High-Quality Standards: Compliance with API 6A ensures that equipment is manufactured to stringent quality standards, resulting in consistent, high-performance products that can handle operational stresses without compromising functionality.
• Reduced Downtime: Reliable, compliant equipment reduces the likelihood of breakdowns and unscheduled downtime, maximizing productivity and minimizing disruptions in drilling and production operations.
• Extended Equipment Life: API 6A-compliant equipment is built to last, with materials and design specifications that improve resilience to wear, corrosion, and fatigue, which prolongs the life of critical wellhead components.

3. Global Industry Acceptance

• International Recognition: API 6A is widely recognized and accepted in the global oil and gas industry, facilitating the use of compliant equipment in various regions and countries. This global standardization promotes consistency in equipment quality and performance.
• Regulatory Compliance: Many countries and operators mandate API 6A compliance for equipment used in oil and gas production, so adherence to this standard can help manufacturers meet local regulatory requirements, enabling smoother market access.

4. Compatibility and Interoperability

• Standardized Components: API 6A standardizes dimensions, tolerances, and connection types, ensuring that components from different manufacturers are compatible. This interoperability simplifies maintenance, upgrades, and replacements.
• Streamlined Operations: With standardized equipment, operators can manage inventories more efficiently and source parts quickly, reducing operational complexity and ensuring smooth integration of new equipment into existing systems.

5. Cost Savings

• Lower Maintenance Costs: Reliable API 6A-compliant equipment typically requires less frequent maintenance, reducing long-term costs associated with repairs, replacements, and maintenance labor.
• Decreased Liability and Insurance Costs: Using certified, compliant equipment can reduce liability in case of an accident, which may also lower insurance premiums for operators by demonstrating a commitment to safety and quality.
• Enhanced Efficiency: By minimizing breakdowns and maximizing uptime, API 6A-compliant equipment improves operational efficiency, resulting in greater productivity and cost-effectiveness over the lifecycle of the equipment.

6. Quality Assurance and Traceability

• Material and Process Control: API 6A compliance mandates strict quality control measures, ensuring the equipment’s manufacturing process and materials meet high standards. This control translates to higher-quality products that perform reliably.
• Traceability: API 6A requires comprehensive documentation and traceability of materials, manufacturing processes, and quality testing. This traceability simplifies inspections, maintenance, and audits, providing operators with detailed information for quality assurance.

7. Competitive Advantage

• Market Differentiation: Manufacturers producing API 6A-certified equipment have a competitive edge, as their products meet recognized standards for safety and performance. API 6A certification often serves as a mark of quality, making equipment more attractive to potential buyers.
• Trust and Credibility: Compliance with API 6A builds trust among clients, regulators, and industry stakeholders, enhancing a company’s reputation and credibility in the market.

8. Compliance with Best Practices and Innovation

• Adherence to Best Practices: API 6A incorporates best practices and the latest knowledge in wellhead and Christmas tree design, ensuring that compliant equipment reflects the most effective, up-to-date solutions for oil and gas production.
• Encourages Innovation: By keeping up with API 6A revisions and updates, manufacturers are encouraged to innovate and improve their products, leading to the development of more advanced, safer, and efficient equipment.

In summary, API 6A compliance is invaluable in the oil and gas industry, offering benefits that include increased safety, reliability, cost savings, and market acceptance. By adhering to these standards, manufacturers and operators contribute to safer and more efficient oil and gas operations worldwide.

API 6A and API 6D are both standards developed by the American Petroleum Institute (API) for the oil and gas industry, but they serve different purposes and apply to different types of equipment. Here’s a breakdown of the key differences between the two:

1. Scope and Application

• API 6A:
  • Focuses on wellhead and Christmas tree equipment used in upstream oil and gas production.
  • Applies to equipment that is installed at the wellhead to control flow, pressure, and safety at the point where the well meets the surface.
  • Typical equipment covered includes casing heads, tubing heads, spools, valves, and connectors specifically designed for high-pressure, high-temperature (HPHT) environments often encountered in oil and gas production.
• API 6D:
  • Focuses on pipelines and pipeline equipment used in the transportation sector (midstream) of the oil and gas industry.
  • Specifically applies to pipeline valves and related equipment for transmission and distribution pipelines.
  • Typical equipment covered includes gate valves, ball valves, check valves, and plug valves used in pipelines that transport oil, gas, and other fluids over long distances.

2. Types of Equipment

• API 6A Equipment:
  • Includes wellhead components and Christmas tree equipment such as valves, chokes, casing, and tubing hangers.
  • Designed for installation directly on the wellhead to manage the flow and pressure of oil or gas from the well.
• API 6D Equipment:
  • Includes pipeline valves like ball, gate, check, and plug valves.
  • Designed for integration into pipeline systems, allowing for the isolation, regulation, and safety control of fluid flow across long pipelines.

3. Design Specifications

• API 6A:
  • Focuses on design features required for wellhead and Christmas tree equipment, such as sealing integrity, pressure and temperature ratings, corrosion resistance, and material strength.
  • Requires equipment to withstand high-pressure and high-temperature (HPHT) conditions, often encountered at the wellhead.
  • Covers different Product Specification Levels (PSLs) to indicate the equipment’s ability to handle varying operational risks.
• API 6D:
  • Specifies design features for pipeline valves, with a focus on durability, sealing integrity, and operability under various pipeline conditions.
  • Primarily concerns equipment that must function reliably over long distances and withstand environmental factors in transmission pipelines.
  • Emphasizes the importance of low-friction designs, as some valves need to open and close frequently during pipeline operations.

4. Testing and Certification

• API 6A:
  • Requires extensive testing, including hydrostatic and material verification tests, to ensure equipment can withstand high pressures at the wellhead.
  • Mandates Product Specification Levels (PSLs) and quality control measures tailored for wellhead equipment, including pressure testing and non-destructive testing (NDT) to verify equipment integrity.
• API 6D:
  • Emphasizes pressure and leakage tests for pipeline valves to ensure they maintain a tight seal and can operate over long pipeline distances.
  • Includes requirements for fire safety tests, as well as maintenance and operability tests, given that these valves are often used in remote and challenging environments.

5. Safety and Environmental Considerations

• API 6A:
  • Addresses the safety risks associated with high-pressure wellheads and the potential for blowouts or uncontrolled releases at the point of extraction.
  • Prioritizes corrosion-resistant materials and high-strength alloys to prevent failure under HPHT conditions.
• API 6D:
  • Focuses on preventing leaks and maintaining the integrity of pipeline valves to ensure environmental protection and reliable flow control across pipelines.
  • Emphasizes the need for low-maintenance and high-reliability valves to reduce the risk of leaks and environmental hazards.

6. Industry Use and Compliance

• API 6A:
  • Predominantly used in upstream operations and is critical for ensuring safety and reliability in oil and gas production.
  • Compliance with API 6A is often required for operators working in exploration and production, where well integrity is critical.
• API 6D:
  • Widely used in midstream operations, particularly in pipeline construction and maintenance for transporting oil and gas.
  • Compliance with API 6D is important for pipeline operators to ensure that pipeline systems are safe, efficient, and environmentally responsible.

In summary, API 6A is focused on wellhead and Christmas tree equipment for upstream oil and gas operations, dealing with HPHT conditions, while API 6D covers valves and related components for pipeline systems, concentrating on long-distance fluid transport in midstream applications. Both standards ensure equipment quality, safety, and reliability, but they address different stages and equipment types within the oil and gas industry.

In conclusion, API 6A and API 6D are essential standards in the oil and gas industry, each addressing distinct aspects of operations to ensure equipment quality, safety, and reliability. API 6A focuses on wellhead and Christmas tree equipment critical to upstream production, ensuring these components withstand high-pressure and high-temperature environments at the wellsite. Meanwhile, API 6D applies to pipeline valves used in midstream transportation, emphasizing durability, leak prevention, and environmental protection across long-distance pipeline systems.

Both standards contribute to the safety and efficiency of oil and gas operations by establishing rigorous design, material, and testing requirements tailored to the demands of each application. Compliance with API 6A and API 6D helps operators meet regulatory requirements, enhance operational performance, and minimize risks to personnel and the environment. By adhering to these standards, manufacturers and operators uphold industry best practices, which are crucial for maintaining safety, reliability, and environmental stewardship in the global oil and gas industry.

What is a Flaring Tool?

What is a semiconductor testing? 8 Types of Semiconductor Testing