Nondestructive Testing (NDT)

Nondestructive Testing (NDT)

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By definition, nondestructive testing and evaluation is the means by which materials and structures may be inspected without disruption or impairment of serviceability. Western Technologies' inspectors and technicians have successfully performed tens-of-thousands of nondestructive field and fabrication shop inspections and tests on structural steel components, connections, and assemblages since 1955. In addition, we have applied nondestructive techniques to manufactured components and castings looking for both surface and subsurface flaws. Western Technologies' personnel are certified for the tests and inspections that they perform by such agencies as ASNT, AWS and ICC. Our NDT equipment is typically portable for use on job sites or in plant facilities, and calibrated in accordance with the applicable code or specification requirements. All test results are evaluated by our knowledgeable and experienced Level II or Level III technicians.

Western Technologies provides inspection and consultation consistent with the following codes and standards:

AWS ♦ API ♦ ASME ♦ ASTM ♦ AWWA ♦ AISC ♦ ASNT ♦ DOT ♦ IBC

Whatever your NDT/NDE needs are, WT can meet them. We are The Quality People.

 

Welder Certification

The American Welding Society (AWS) has developed a program for certifying welders to national standards that is recognized by many industries. Western Technologies has AWS Certified Welding Inspectors (CWIs) capable of conducting the AWS certification.

 

Welding Procedure Qualification

Western Technologies performs the testing necessary to qualify both your welders and your weld procedure. In addition, our staff Certified Welding Inspectors (CWIs) are available to help you sort out the requirements of the specification to which you are qualifying, and assist you through the required paperwork.

Our comprehensive machine shop, with large sawing capabilities, prepares the tensile, bend, macro etch or impact test specimens from your welded samples. These prepared specimens, called coupons, are then tested according to your required specification. The resulting test data provides the basis of the procedure qualification.

 

Weld Examination

The philosophy that often guides the fabrication of welded assemblies and structures is "to assure weld quality". The first step in assuring weld quality is to determine the degree required by the application, and so a standard is established based on the service requirements. Standards designed to impart weld quality may differ from job to job, but the use of appropriate examination techniques can provide assurance that the applicable standards are being met. Whatever the standard of quality, all welds should be inspected.

Nondestructive examination (NDE) methods of inspection make it possible to verify compliance to the standards on an on-going basis by examining the surface and subsurface of the weld and surrounding base material. After visual examination, four basic methods are commonly used to examine finished welds — ultrasonic, liquid or dye penetrant, magnetic particle, and radiographic (X-ray), and phased array. Western Technologies can perform all five either on the job site, in the fabrication plant, or in our laboratories.

Ultrasonic Testing (UT)
Ultrasonic testing is a method of detecting discontinuities by directing a high-frequency sound beam through the base plate and weld on a predictable path. When the sound beam's path strikes an interruption in the material, some of the sound is reflected back. The sound is collected by the instrument, amplified and displayed on a video screen. Both surface and subsurface defects in metals can be detected, located and measured by ultrasonic inspection, including flaws too small to be detected by other methods.

Ultrasonic examination requires expert interpretation from highly skilled and extensively trained and certified personnel. Western Technologies' NDT staff is all that and more.

Penetrant Testing (PT)
An industry standard for decades, liquid penetrant inspection remains one of the most reliable, efficient, and cost-effective methods for detecting surface flaws in non-porous metals, and can be used with austenitic steels and nonferrous materials.

Magnetic Particle Testing (MT)
Magnetic particle testing is a method of locating and defining discontinuities in magnetic materials. It is a good method for detecting surface cracks of all sizes in both the weld and adjacent base metal, subsurface cracks, incomplete fusion, undercut and porosity in the weld and base metal. Although not a substitute for radiography or ultrasonic testing for subsurface evaluations, it may present an advantage over those methods in detecting tight cracks and surface discontinuities. Magnetic particle inspection produces exacting results, so Western Technologies' staff is able to not only locate defects, but also assess their degree of severity.

Radiographic Testing (RT)
After more than a century of use, radiography (X-ray) is still one of the most important, versatile and widely accepted of all nondestructive examination methods. Radiography is based on the ability of X-rays and gamma rays to pass through metal and other materials opaque to ordinary light, and produce photographic records of the transmitted radiant energy. All materials will pass through known amounts of this radiant energy and, therefore, X-rays and gamma rays can be used to show discontinuities and inclusions within opaque materials. The permanent film record of the internal conditions will show the basic information by which weld soundness can be determined.

Phased Array Testing (PA)
Phased array ultrasonics (PA) is an advanced method of non-destructive ultrasonic testing which can be used to find flaws in manufactured materials such as welds.

This method allows the operator to control parameters such as beam angle and focal distance to efficiently detect material defects with a high degree of accuracy and clarity.

To test or interrogate a large volume of material, a conventional probe must be physically scanned (moved or turned) to sweep the beam through the area of interest. In contrast, the beam from a phased array probe can be moved electronically, without moving the probe, and can be swept through a wide volume of material at high speed. The beam is controllable because a phased array probe is made up of multiple small elements, each of which can be pulsed individually at a computer-calculated timing.

 

Radiography (NDT)

Radiographic nondestructive (NDT) inspection involves the use of X-rays or gamma rays to examine parts or products for imperfections. Western Technologies utilizes radioactive isotopes to direct radiation through a part or product onto radiographic film. The film is either developed in our laboratory dark room or one of our mobile units and can then be interpreted by one of our experienced ASNT certified technicians.

Radiography can be used as a tool for locating reinforcing steel, conduit, post-tensioned cables or other embedment in concrete slabs and columns. Western Technologies is staffed with certified technicians and outfitted with the latest technical and image processing equipment to evaluate, inspect, and certify to the applicable standard a wide variety of products for the aerospace, power generation, military, nuclear, forensic, commercial, and construction industries.

 

Ground Penetrating Radar (GPR)

This nondestructive (NDT) method uses electromagnetic radiation in the microwave band (UHF/VHF frequencies) of the radio spectrum, and detects the reflected signals from subsurface structures. GPR can be used in a variety of media including rock, soil, ice, fresh water, pavements and structures. It can detect objects, changes in material, voids and cracks.

GPR may be utilized by construction professionals as a means to locate targets within and below concrete prior to core drilling or saw cutting. GPR is more accurate, efficient and safer to use than radiography (X-ray). No radiation is involved, so after hours work or clearing of areas is not required. Only single sided access is required for Western Technologies to image any size area quickly and accurately.

 

Infrared Thermography (NDT)

Everything above absolute zero degree temperatures radiates energy in the infrared spectrum. Thermography is a nondestructive (NDT) infrared imaging technique that utilizes an electronic detection system (camera) to display variations in infrared radiation. This technology detects changes in thermal energy (electromagnetic radiation), which is viewed directly on screen and/or converted to a file for storage or hard copy printout.

Examination of walls and ceilings using infrared thermography can reveal water penetrations or unconditioned air penetration into a home or building. Structures benefit from periodic infrared thermography surveys that identify leaks in roofs and energy inefficiencies. Regularly monitoring structures and equipment allow clients to foresee faults before they become problems.

Infrared examinations provide critical information on the condition of your electrical and mechanical equipment. Regular periodic inspections drastically reduce unexpected failures and downtime by detecting abnormal temperature patterns that may signify corrosion, damaged wiring, loose connections, faulty breakers, and/or insulation breakdown. Infrared inspections are also useful in evaluating circuit wiring, transformers, and insulators.

Western Technologies employs certified inspectors to conduct nondestructive (NDT) infrared surveys.

 

Special Testing

Construction Vibration Monitoring
Before blasting or other construction vibrations begin on your project, Western Technologies technicians can conduct pre-construction surveys to document the existing conditions that are very important in later evaluation and discussion of the accuracy and validity of damage claims.

Blasting plans will normally provide for monitoring of peak particle velocities at critical structures or at the closest occupied residences. A seismograph that records motion on three orthogonal axes is typically used to monitor blasting vibrations. These instruments have evolved into small battery-operated units that are triggered by the initial motion to record the motions associated with blasting. The data can be downloaded into a laptop computer for evaluation.

Load Testing
Load testing of building components or elements is a standard means of demonstrating a structure's capabilities when a simple analysis is not practical or requires confirmation. Typical situations that may arise include:

  • Unknown strength parameters.
  • Change of use.
  • Fire damage.
  • Materials defects.
  • Suspect performance.
  • Routine verification of lifting equipment.

A variety of loading techniques can be used according to the weight required, the condition of the building and logistical limitations. Water and bagged sand are the most common methods.

Monitoring of deflections is undertaken either electronically, using dial gauges, or by survey, other concerns may also be measured such as crack widths, strains and temperature.

Paint Thickness
Virtually everything in the modern world has a paint, varnish, sealant or other coating — from armor piercing bullets to petroleum storage tanks. Even simple house paint is an advanced chemical product. Understanding the properties and thickness of these coatings is critical to predicting their long term performance.

Other Special Testing

  • Bridge Elastomeric Bearing Pads
  • Static Coefficient of Friction
  • O-Rings
  • Gaskets
  • Rebar Tensile Strength
  • Post-Tension Cable Tensile Strength
  • Plastic (PVC, HPDE) Pipe
  • Architectural Stone
  • Flexure and Shear

Typically Performed Test Procedures

A325      Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi
Minimum Tensile Strength
A370      Standard Test Methods and Definitions for Mechanical Testing of Steel Products
A416      Standard Specification for Steel Strand, Uncoated Seven-Wire for Prestressed
Concrete
A490      Standard Specification for High-Strength Steel Bolts, Classes 10.9 and 10.9.3, for
Structural Steel Joints
A615      Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete
Reinforcement
A706      Standard Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete
Reinforcement
C1354    Standard Test Method for Strength of Individual Stone Anchorages in Dimension
Stone
D395      Standard Test Methods for Rubber Property – Compression Set
D412      Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers –
Tension
D429      Standard Test Methods for Rubber Property – Adhesion to Rigid Substrates
D573      Standard Test Method for Rubber – Deterioration in an Air Oven
D751      Standard Test Methods for Coated Fabrics
D1056    Standard Specification for Flexible Cellular Materials – Sponge or Expanded
Rubber
D1415    Standard Test Method for Rubber Property – International Hardness
D2240    Standard Test Method for Rubber Property – Durometer Hardness
D4014    Standard Specification for Plain and Steel-Laminated Elastomeric Bearings for
Bridges
D4787    Standard Practice for Continuity Verification of Liquid or Sheet Linings Applied to
Concrete Substrates
D5162    Standard Practice for Discontinuity (Holiday) Testing of Nonconductive Protective
Coating on Metallic Substrates
E10         Standard Test Method for Brinell Hardness of Metallic Materials
E18         Standard Test Methods for Rockwell Hardness of Metallic Materials
E94         Standard Guide for Radiographic Examination
E110       Standard Test Method for Indentation Hardness of Metallic Materials By Portable
Hardness Testers
E114       Standard Practice for Ultrasonic Pulse-Echo Straight-Beam Examination By The
Contact Method
E164       Standard Practice for Contact Ultrasonic Testing of Weldments
E165       Standard Practice for Liquid Penetrant Examination for General Industry
E190       Standard Test Method for Guided Bend Test for Ductility of Welds
E213       Standard Practice for Ultrasonic Testing of Metal Pipe and Tubing
E273       Standard Practice for Ultrasonic Examination of The Weld Zone of Welded Pipe
and Tubing
E290       Standard Test Methods for Bend Testing of Material for Ductility
E587       Standard Practice for Ultrasonic Angle-Beam Examination By The Contact
Method
E605       Standard Test Methods for Thickness and Density of Sprayed Fire-Resistive
Material (SFRM) Applied to Structural Members
E709       Standard Guide for Magnetic Particle Testing
E736       Standard Test Method for Cohesion/Adhesion of Sprayed Fire-Resistive
Materials Applied to Structural Members
E797       Standard Practice for Measuring Thickness By Manual Ultrasonic Pulse-Echo
Contact Method
E999       Standard Guide for Controlling The Quality of Industrial Radiographic Film
Processing
E1030     Standard Test Method for Radiographic Examination of Metallic Castings
E1032     Standard Test Method for Radiographic Examination of Weldments
E1220     Standard Test Method for Visible Penetrant Examination Using The Solvent-
Removable Process
E1417     Standard Practice for Liquid Penetrant Testing
E1418     Standard Test Method for Visible Penetrant Examination Using The Water-
Washable Process
E1444     Standard Practice for Magnetic Particle Testing
E1742     Standard Practice for Radiographic Examination
E1901     Standard Guide for Detection and Evaluation of Discontinuities By Contact
Pulse-Echo Straight-Beam Ultrasonic Methods
F36         Standard Test Method for Compressibility and Recovery of Gasket Materials
G62        Standard Test Methods for Holiday Detection in Pipeline Coatings

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