WELDING INSPECTION & QC

WELDING INSPECTION & QC

QA/QC is the combination of quality assurance, the process or set of processes used to measure and assure the quality of a product, and quality control, the process of meeting products and services to consumer expectations.

Quality assurance, or QA for short, refers to a program for the systematic monitoring and evaluation of the various aspects of a project, service, or facility to ensure that standards of quality are being met.

Quality control emphasizes testing of products to uncover defects, and reporting to management who make the decision to allow or deny the release, whereas quality assurance attempts to improve and stabilize production, and associated processes, to avoid, or at least minimize, issues that led to the defects in the first place.

Nondestructive testing or Non-destructive testing (NDT) is a wide group of analysis techniques used in science and industry to evaluate the properties of a material, component or system without causing damage.

The terms Nondestructive examination (NDE), Nondestructive inspection (NDI), and Nondestructive evaluation (NDE) are also commonly used to describe this technology.

Common NDT methods include ultrasonic, magnetic-particle, liquid penetrant, radiographic, remote visual inspection (RVI), eddy-current testing, and low coherence interferometry.

Terminology

?WPS – Weld Procedure Specification:

• ?Qualified instructions on how to complete the weld.
• ?A WPS is a written (qualified) welding procedure prepared to provide direction for the making of production welds.

?PQR – Procedure Qualification Record (ASME) & WPAR – Weld Procedure Approval Record:

• ?Record of the welding parameters and test results
• ?A PQR is a record of welding data used to weld a test coupon

?Welder Qualification Test certificate & Welder Performance Qualification (ASME):

• ?Record of Welder test results and range of approval

Welding Inspector (WI) ?

• Inspect welds

Three basic work function categories:

• Overseer: code inspector
• Specialist: NDT radiographer
• Combination of overseer and specialist

WI – Essential Requirements:

• Physical Condition
• Attitude
• Knowledge of Welding
• Knowledge of Drawings, Specifications, and Procedures
• Knowledge of Testing Methods
• Records
• Education and Training
• Welding Experience
• Inspection Experience
• Certification of Qualification

Welding Inspection Operations

• Knowledge of drawings, standard/codes/specifications, and manufacturing instructions
• Verification of the manufacturer’r approved quality assurance program
• Verification of welder and inspector qualifications
• Verification of approved procedures for qualifying welders and inspection personnel
• Verification that approved welding and inspection procedures are being used
• Selection of production test samples
• Evaluation of test results
• Preparation of test reports and storage of records
• Safety

Typical Welding Inspection Procedure

Prior to welding

• Material identification
• Chemical analysis
• Mechanical properties

Joint geometry (fit-up)

• Edge preparation (including root face and beveling)
• Dimensions
• Cleanliness
• Root opening
• Tacking
• Backing (where required)

During welding

• Preheat and interpass temperatures
• Filler Metal
• Root Pass
• Root preparation prior to welding second side
• Cleaning between passes
• Appearance of passes
• In-process NDT inspection as required or specified
• Conformance to approved welding procedure

After welding

• Postheat treatment requirements

Acceptance inspection

• Method of cleaning for inspection
• Visual inspection
• Nondestructive testing (NDT)
• Destructive testing
• Repairs

?Visual inspection

• Surface contour and finish of welds
• ?Conformity of welds with drawings

Nondestructive testing (NDT)

• ?Magnetic particle and liquid penetrant tests
• ?Radiography
• ?Ultrasonic tests
• ?Proof testing
• ?Other suitable methods

Destructive testing

• ?Chemical
• ?Mechanical
• ?Metallographic

Preparation of Records & Reports

• An inspector should be able to maintain adequate records.
• To check all records for completeness and accuracy in accordance with specified requirements.
• To make certain that records are available when needed.
• Any records that require the fabricator’s signature should be prepared by the fabricator rather than the inspector.
• Records should be in as much detail as necessary.
• It is desirable that the inspector comment on th general character of the work, how well it stayed within prescribed tolerances, difficulties that occurred, and any defects.
• Any repair should be explained
• Copies of this records should go to all persons entitled to received them, and the inspector should keep a copy in his own file.