Vancouver Island
18-4970 Polkey Road
Duncan, B.C.
V9L 6W3
(250) 508-9155
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Kelowna
9500 Jim Bailey Road,
Kelowna BC,
V4V 1S5
(250) 508-9155
NDT – Non-Destructive Testing
Quick Links:
MAGNETIC PARTICLE TESTING:
Using electro-magnetic fields in the testing of ferro-magnetic materials for surface oriented defects. The use of Magnetic Particle testing in the shop or field is typically done with a Yoke, (see photo below) by placing the legs on either side of a weld or an area of concern, initiating a magnetic field by pressing the trigger and introducing ferro-magnetic particles(essentially metal shavings) to the magnetic field on the test surface,(also known as Dry Magnetic Particle). If there is a surface defect (crack, lamination, weld undercut, etc) the magnetic field in that area has to cross over the defect causing a condition call flux leakage which draws the metal shavings to that area highlighting the defect.
This is one of the most common testing methods requested of a third-party inspection company. Of course it can only be conducted on ferro-magnetic material, (steel), and cannot be used on steel which has been painted with anything more than 2mils of paint, (essentially a primer coat). It is used extensively in the inspection of:
- Cranes (but only in areas suspected of cracking because of the paint issue)
- Bridges
- Ships
- Aircraft components
- Structural steel for buildings
- Transport Vehicles (Rail cars, automotive etc)
- Welds and Root Welds (the first pass in a mulipass weld)
Magnaflux
MPI Testing – Pinion Arm Splice Weld
Related Techniques:
Wet Magnetic Particle:(also known as Black and White because you first paint the surface with a white primer and then apply the magnetic field and particles which come out of the can looking slightly black, hence the name) It is the same process as Dry Magnetic Particle except the ferro-magnetic particles (metal shavings) are in an aerosol spray. This process is slightly more sensitive than the Dry Particle method.
Fluorescent Magnetic Particle: The same process as Wet Magnetic Particle except the aerosol spray has a fluorescent component and therefore must be observed using a black light and the inspection area must be darkened to no more than 15 footcandles. This is the most sensitive of all the Magnetic Particle processes. This process can also be used in a lab on stationary equipment call a Horizontal Wet Bench which is a service we also supply.
LIQUID PENETRANT TESTING:
This is one of the oldest DNT methods originally created to check some of the first train wheels using gear oil and talcum powder. The modern day process uses low viscosity dies to penetrate surface imperfections and reveal surface oriented defects, (also known as Visible Dye Penetrant). In the shop or field this process is typically done using aerosol canes and consists of 5 steps. First, pre-clean the surface to be tested. The client should clean test areas of slag and heavy contaminants such as grease, dirt and paint (surface must be open to the penetrants), but the technician will always preclean the test area prior to this test. Second, apply penetrants. Third, after allowing the penetrant to soak in (dwell time), completely clean the surface of penetrants and apply the developer (like an aerosol form of talcum powder). The developer draws the remaining penetrant out of any surface oriented defects. Fourth is interpretation of indications in accordance with the specification. Fifth, is post cleaning. This process is used extensively in the inspection of:
- Non ferro-magnetic materials (aluminum/stainless steel/copper/ bronze/etc)
- Machined surfaces
- Tanks and vessels with “No Leak” requirements
- Aircraft components
- Welds
Penetrant testing on stainless Burner Nozzles
Related Techniques:
Fluorescent Liquid Penetrant: The same process as Visible Dye Penetrant except the penetrant is in a Fluorescent formulation and therefore must be viewed using a blacklight.
In this process a developer is not used but as in all fluorescent testing the inspection area must be darkened to a maximum of 15 footcandles . This is the most sensitive form of Penetrant testing.
Penetrant testing on a larger scale is done with dip tanks and drying ovens where we would test, on average, 1700 brake peddle castings a shift. In the field, large projects are things like the 18ft diameter turbine shafts, that took 24 gallons of penetrant, and the larger vessel projects you find in the resource industry.
ULTRASONIC TESTING:
Using high frequency sound to identify internal variations in the structure of a material. In the shop and field applications this typically consists of coupling a transducer, (a gel is applied to the surface to eliminate air between the transducer and the test surface), emitting high frequency sound to the test material. This “Ultra Sound” travels through the test material and is then used to identify any voids or discontinuities in the material.
Two basic forms of Ultrasonic testing are:
- Straight Beam Testing which uses a transducer angled at 90 to the surface. This method is typically used for lamination scans (laminations are air pockets in the steel ingot that when it gets rolled into plate or whatever, the pocket gets fattened and stretched out but never fuses). Also, accurate digital thickness measurements of material such as ship hulls, boiler plate etc, for the use in corrosion surveys.
- Angle Beam Testing which uses a transducer angled at typically 45°,60° or 70° to the surface. This method is almost exclusively used for the testing of welds.
Angle Beam Testing
When you’re selling this service to a client you will find that many times their contract documents will say “Radiograghy or Ultrasonic testing required”. What you have to sell them on is the advantages of using Ultrasonics over Radiography…. which are;
- Ultrasonic testing can be done without interruption in production. Radiography requires a safe zone of approximately 50’ around any testing.
- Ultrasonic testing locates deficiencies in two directions, where it is in the length of weld and what depth the deficiency is at in the weld. Radiography will not tell depth other than the sharpness of the defect image on the film, which will only tell generally whether the defect is closer to the film or the source. See radiography below.
- Also it is considerably cheaper. An RT truck on the island is worth about $150/hr. We charge out at $75.
- Ultrasonic can be carried out from one side of the weld only. Radiography always requires access to both sides. See radiography below.
Related Techniques:
- Ship Hull Thickness Survey
- Lamination Scans
- Weld Inspection
- Shaft/Bolt Inspection
RADIOGRAPHY:
Using radioactive source to reveal internal variations in the structure of a material. Radioactive sources are generally Iridiun192, although Cobalt 60 can be used for much heavier thickness. Generally, the process consists of setting up a radioactive source at a predetermined distance from the test surface positioning the film on the other side of the test piece and exposing the test piece and the film to radiation.
Radiography Procedure
The film is then developed in a darkroom and the final image looks similar to a large negative (usually 4-1/2” x 17”).
WE ARE CERTIFIED TO DO THIS TECHNIQUE BUT WE DO NOT OFFER THIS SERVICE.
Our technicians are available for film interpretation.
Related Techniques:
Fluorescent Liquid Penetrant: The same process as Visible Dye Penetrant except the penetrant is in a Fluorescent formulation and therefore must be viewed using a blacklight.
In this process a developer is not used but as in all fluorescent testing the inspection area must be darkened to a maximum of 15 footcandles . This is the most sensitive form of Penetrant testing.
Penetrant testing on a larger scale is done with dip tanks and drying ovens where we would test, on average, 1700 brake peddle castings a shift. In the field, large projects are things like the 18ft diameter turbine shafts, that took 24 gallons of penetrant, and the larger vessel projects you find in the resource industry.
NACE COATING INSPECTION:
Industrial Coatings Inspection is the inspection of surface preparation, paint application, dry film thickness surveys and monitoring of environmental conditions prior to, during application and through the curing stages of the coating system(paint). Industrial paints have come a long way since their inception after the first world war. Now industrial coatings can protect surfaces against damage caused from exposure to chemicals, sea water, extreme heat, abrasion and the effects of the suns UV. The problem is that now these paints have very stringent requirements for application. Anchor profile, surface cleanliness, air temperature, substrate temperature and dew point are all critical to achieving an effective coating system. If industrial paint is applied without regard for just one of the above criteria, failures can be catastrophic. I’ve seen pin-point corrosion breach a vessel in half the time it would have taken if they hadn’t painted it at all. Simply because it was painted without consideration for the above noted criteria.
The tools involved in this type of inspection are either a wheeling sycrometer (manual) or digital. This tells you air temperature, dew point and wet and dry bulb temperatures. Surface temperature gages or infrared surface gage. Profile gage which tells you the depth of the surface profile created by abrasive blasting (sand blasting). Film thickness gages to measure dry film thickness of the paint after it’s dried. And finally, a Holiday Tester which is an instrument to identify and located any pinholes in the applied coating. The reason I’m mentioning these instruments is because when you are trying to sell this service, I can almost guarantee that one of the above instruments will come up in the discussion and you will be expected to know what it is and what it’s used for. Sometimes you will be selling this service to a painting contractor and the service should be sold on the common sense that would be applied to the specification requirements by the inspector. When selling this service to a steel contractor who is hiring a painting company, the focus of the sale should be on the coordination skills of the inspector to ensure the coating application is done right, and within the schedule dictated by the steel fabricator. When selling this service to the end user or the owner you must sell the service on the extensive experience and the ability of the inspector to maintain the highest level of quality and yet keep the job on track and schedule.
Magnified view of a grit blasted surface
Related Techniques:
- Project Management
- Specification Writing
- Holiday Testing (using an electrical conductivity meter to identify holes,(holidays), in a coatings surface)
VISUAL WELD INSPECTION:
Visual inspection of welding for size, location and quality in accordance with project specifications and a variety of codes. In the field or shop this service consists of just about anything the client wants. I have done everything from welding supervision to corrosion surveys on large ocean-going tankers. From weld surveys in nuclear generation stations to inspecting the roof attachment points on the Holland Tunnel (under the St Clair River in Windsor Ont. One of the nastiest places I’ve ever had to go). Usually, the only reason a steel fabricator will require this service is because he’s being forced to by his project specification.
This is much more a service to market to engineering firms which are looking for someone to do all the dirty work, so they don’t have to. I have asked Darrell to bring the engineer in to market the big engineering firms but this is a service you should always push to outfits like BC Ferries, Public Works and any of the municipalities, sewage treatment plants and all the procurement bodies with the provincial and federal governments. Always talk about the fact that bringing in a third-party inspection company distances the client from any of the liability inherent in any project, large or small. It is always useful to be knowledgeable about the history and experience of your inspectors when marketing the Visual Inspection Service. Clients want to know that the inspectors their hiring are not only certified but also have the experience on their specific type of work.
Related Techniques:
- Dimensional Inspections
- Welding Parameter Monitoring
- Welding Supervision
- Welding Technology Consultant
- Torque Testing
- Hardness Testing
CRANE INSPECTION & CERTIFICATION:
Full crane structural inspection in accordance with Work Safe BC OHSR, (occupational health and safety regulations), complete with engineering certification.
Related Techniques:
- Rigging Equipment Inspections
- Wire Rope inspection
- Stability Testing
ENGINEERING:
Welding procedures, crane certification, repair procedures and project supervision.
Codes and Specifications:
You should be familiar with the codes in this list to at least the degree of knowing generally what subject they pertain to.
- CSA W59 Welded Steel Construction-This is the bible to most companies involved in steel construction(AWS D1.1 is the American version)
- CSA W178 Certification of Welding Inspection Companies
- CSA W47.1 Welding Consumables
- CSA S16 Design of Steel Structures
- SSPC Good Painting Practices – This is the bible to all industrial painting companies. Part of this code is the section PA2 which tells you how to conduct most of the major coatings tests used by inspection companies.
- CSA C225 – Truck Mounted Arial Devices
- CSA Z150 – Safety Standard For Mobile Cranes
- CSA Z248 – Tower Cranes
- CSA B354.4-Self Propelled Manlifts
Our technicians are fully certified to:
- CSA W178.2 Visual Welding Inspection
- CGSB 48.9712-2000 for Ultrasonic Testing
- Radiographic Testing
- Liquid Penetrant Testing
- Magnetic Particle Testing
- NACE (National Association of Corrosion Engineers) Certified Coating Inspector
