Welding Certification tests are numbered by position and joint type. For instance a 1 G indicates a flat position groove weld. The 1 means flat position, and the G indicates a groove weld.

I saw a video the other day that advertised a mobile welding lab that was used to train and certify welders.

A few students as well as the instructor were interviewed and described the 8 weeks of welding training that led up to welding certification tests in the 1G position.

What?

That's right, 8 weeks of welding training per process to be able to certify in a 1 G weld test.

I don't get it. After 8 weeks of training in a welding process, why can't the welder pass some other positions like 3G and 4G welding tests?

Did you know that a 3G plate test combined with a 4G plate test certifies a welder in ALL positions?

That's all positions. Like 1G , 2G, 3G, and 4G. as well as every position of fillet welds imaginable too.

A 1G welding test certifies a welder to weld in how many positions? One ! that's it ...just one.

You get a lot more bang for your buck by training welders to certify in both the 3G and 4G positions.

Another issue is that 1G welding tests typically don't have very good pass rates.

You know why?

Gravity. That's right., gravity is working against you and not for you. Gravity lets the slag flow ahead of the arc on a 1G welding test and if you are not careful, it can cause cold lap and slag inclusions.

Gravity works For you and not against you on a 3G vertical plate welding test.

Gravity keeps the flux behind the arc. The arc is then allowed to do its thing and penetrate into the base metal. As long as you maintain enough amperage and a tight arc, things will go well on a 3G vertical plate test.

The AWS (American Welding Society) classifies the 1G position welding test as the easiest.

I disagree with that when it comes to beveled groove welds.

I believe 2G horizontal and 3G vertical welding certification tests have better pass rates when it comes to a bend test or x ray testing.

» Read More...

1. Inspect Your Motorcycle Regularly

Make up a checklist of the important things you should inspect regarding your motorcycle’s safety and performance. Send it to the service center as well every time you cover 5,000 kilometers. Regular visits may cost you a small amount of money but this amount is certainly nothing considering that it’s equivalent to the price of your life!

2. How Oily is Oily?

Make it a habit to check your motorcycle’s oil level when you’ve stopped for gas. While checking the oil, make sure that no foreign material will accidentally fall into your motorcycle’s oil storage compartment. Avoid subjecting your motorcycle to constant exposure to extremely hot or cold weather as this can affect your oil’s quality.

3. Batteries are a Motorcycle’s Best Friend
Do you know that one of the most common causes for motorcycles to cease operating or malfunction is due to battery problems? As such, you need to take excellent care of your battery at all times. Firstly, never remove or replace them if the engine is still running. Do not change batteries by yourself if you don’t have any experience.

4. Adding Fuel to the Fire

An absence of care and precaution can easily add fuel to the fire and lead you to experiencing an unfortunate accident. To avoid fuel troubles, start by learning the various locations and uses of your motorcycle’s fuses. When changing fuses, always subject it to testing to ensure that it’s in good working condition. Damaged fuses put you at the risk of having your motorcycle’s blow up while you’re on the driver seat.

5. Clean Up Your Act

Believe it or not the mere act of cleaning can significantly reduce future maintenance costs and the chances of having an accident while you’re riding your motorcycle. If you do not like the idea of regular cleaning, just think of it as killing two birds with one stone: cleaning will let you enjoy a safer and cooler ride on your bike!

6. Your Motorcycle’s First Aid Kit

Always have a properly equipped toolbox strapped to your motorcycle. Even the world’s slowest and safest driver can still be an unfortunate victim of an accident so having a toolbox will just be your way of preparing for any eventuality!

» Read More...

Description:

Non destructive testing NDT) are noninvasive techniques to determine the integrity of a material, component or structure or quantitatively measure some characteristic of an object. In contrast to destructive testing, NDT is an assessment without doing harm, stress or destroying the test object. The destruction of the test object usually makes destructive testing more costly and it is also inappropriate in many circumstances.

NDT plays a crucial role in ensuring cost effective operation, safety and reliability of plant, with resultant benefit to the community. NDT is used in a wide range of industrial areas and is used at almost any stage in the production or life cycle of many components. The mainstream applications are in aerospace, power generation, automotive, railway, petrochemical and pipeline markets. NDT of welds is one of the most used applications. It is very difficult to weld or mold a solid object that has no risk of breaking in service, so testing at manufacture and during use is often essential.

While originally NDT was applied only for safety reasons it is today widely accepted as cost saving technique in the quality assurance process. Unfortunately NDT is still not used in many areas where human life or ecology is in danger. Some may prefer to pay the lower costs of claims after an accident than applying of NDT. That is a form of unacceptable risk management. Disasters like the railway accident in Eschede Germany in 1998 is only one example, there are many others.

For implementation of NDT it is important to describe what shall be found and what to reject. A completely flawless production is almost never possible. For this reason testing specifications are indispensable. Nowadays there exists a great number of standards and acceptance regulations. They describe the limit between good and bad conditions, but also often which specific NDT method has to be used.

The reliability of an NDT Method is an essential issue. But a comparison of methods is only significant if it is referring to the same task. Each NDT method has its own set of advantages and disadvantages and, therefore, some are better suited than others for a particular application. By use of artificial flaws, the threshold of the sensitivity of a testing system has to be determined. If the the sensitivity is to low defective test objects are not always recognized. If the sensitivity is too high parts with smaller flaws are rejected which would have been of no consequence to the serviceability of the component. With statistical methods it is possible to look closer into the field of uncertainly. Methods such as Probability of Detection (POD) or the ROC-method "Relative Operating Characteristics" are examples of the statistical analysis methods. Also the aspect of human errors has to be taken into account when determining the overall reliability.

Personnel Qualification is an important aspect of non-destructive evaluation. NDT techniques rely heavily on human skill and knowledge for the correct assessment and interpretation of test results. Proper and adequate training and certification of NDT personnel is therefore a must to ensure that the capabilities of the techniques are fully exploited. There are a number of published international and regional standards covering the certification of competence of personnel. The EN 473 (Qualification and certification of NDT personnel - General Principles) was developed specifically for the European Union for which the SNT-TC-1A is the American equivalent.

The nine most common NDT Methods are shown in the main index of this encyclopedia. In order of most used, they are: Ultrasonic Testing (UT), Radiographic Testing (RT), Electromagnetic Testing (ET) in which Eddy Current Testing (ECT) is well know and Acoustic Emission (AE or AET). Besides the main NDT methods a lot of other NDT techniques are available, such as Shearography Holography, Microwave and many more and new methods are being constantly researched and developed.

NDT Applications and Limitations

NDT Method	Applications	Limitations
Liquid Penetrant	used on nonporous materials can be applied to welds, tubing, brazing, castings, billets, forgings, aluminium parts, turbine blades and disks, gears	need access to test surface defects must be surface breaking decontamination & precleaning of test surface may be needed vapour hazard very tight and shallow defects difficult to find depth of flaw not indicated
Magnetic Particle	ferromagnetic materials surface and slightly subsurface flaws can be detected can be applied to welds, tubing, bars, castings, billets, forgings, extrusions, engine components, shafts and gears	detection of flaws limited by field strength and direction needs clean and relatively smooth surface some holding fixtures required for some magnetizing techniques test piece may need demagnetization which can be difficult for some shapes and magetizations depth of flaw not indicated
Eddy Current	metals, alloys and electroconductors sorting materials surface and slightly subsurface flaws can be detected used on tubing, wire, bearings, rails, nonmetal coatings, aircraft components, turbine blades and disks, automotive transmission shafts	requires customized probe although non-contacting it requires close proximity of probe to part low penetration (typically 5mm) false indications due to uncontrolled parametric variables
Ultrasonics	metals, nonmetals and composites surface and slightly subsurface flaws can be detected can be applied to welds, tubing, joints, castings, billets, forgings, shafts, structural components, concrete, pressure vessels, aircraft and engine components used to determine thickness and mechanical properties monitoring service wear and deterioration	usually contacting, either direct or with intervening medium required (e.g. immersion testing) special probes are required for applications sensitivity limited by frequency used and some materials cause significant scattering scattering by test material structure can cause false indications not easily applied to very thin materials
Radiography Neutron	metals, nonmetals, composites and mixed materials used on pyrotechnics, resins, plastics, organic material, honeycomb structures, radioactive material, high density materials, and materials containing hydrogen	access for placing test piece between source and detectors size of neutron source housing is very large (reactors) for reasonable source strengths collimating, filtering or otherwise modifying beam is difficult radiation hazards cracks must be oriented parallel to beam for detection sensitivity decreases with increasing thickness
Radiography X-ray	metals, nonmetals, composites and mixed materials used on all shapes and forms; castings, welds, electronic assemblies, aerospace, marine and automotive components	access to both sides of test piece needed voltage, focal spot size and exposure time critical radiation hazards cracks must be oriented parallel to beam for detection sensitivity decreases with increasing thickness
Radiography Gamma	usually used on dense or thick material used on all shapes and forms; castings, welds, electronic assemblies, aerospace, marine and automotive components used where thickness or access limits X-ray generators	radiation hazards cracks must be oriented parallel to beam for detection sensitivity decreases with increasing thickness access to both sides of test piece needed not as sensitive as X-rays

» Read More...