Visual inspection is a non-destructive testing (NDT) weld quality testing process where a weld is examined with the eye to determine surface discontinuities. It is the most common method of weld quality testing.
Most construction jobs will likely ask for a 3G and 4G combo MIG welding test.
Weld Testing can broadly be broken down into two different types; non-destructive testing (NDT) and destructive testing.
A Welder Performance Qualification (WPQ) is a test certificate that shows whether a welder possesses the necessary experience and knowledge to perform the specifications of a particular weld procedure.
Pipe welding is considered one of the more difficult processes for welders to master. In order to pass pipe welding tests, you must be able to join two cylindrical metal pipes together utilizing shielded metal arc welding or any number of other methods.
The 6G pipe weld is one of the most difficult weld certification tests to pass because the pipe is at a 45-degree angle and immovable. Welders performing the 6G certification test must weld in all positions including horizontal, vertical and overhead, and may have to weld both right-handed and left-handed.
The 1G welding certification position is a plate in the flat position that is beveled. This position is the most basic and only covers the welder in that position. It's the easiest test to pass and the least desired by employers.
Visual Inspection Of The Weld
The basic method of checking the quality of a weld is to inspect it for any flaws visually. Look for any cracks, beads, bends, craters, excessive reinforcements, or other flaws and inform any concerned authorities about it.
If either weld fails, you may retest at any time within a month, but you must deposit two sound welds of that type. You may not test again for six months if you fail the retest, and when you test again you must fabricate two weld tests plates of the type and position you previously failed.
The most common used codes or regulations are API Standard 1104, American Petroleum Institute— Used for pipelines, ASME Section IX, American Society of Mechanical Engineers—Used for pressure vessels and nuclear components, and AWS D1. 1, American Welding Society—Used for bridges, buildings, and other structural steel.
Immediate Retest Using Radiography
A welder who fails to satisfy the radiographic acceptance criteria for a welded test coupon is allowed an immediate retest but must make two consecutive test coupons, for each failed test, and both must satisfy the radiographic acceptance criteria.
The three most common welding types are – Arc, MIG and TIG welding.
A weld test in 1G position simulates one circumstance a welder may encounter on the job. The term 1G refers to the position of the welded materials or weld axis, which lay flat on a welding surface during the test.
Pulling a vacuum onto a weldment. Spraying helium in very small amounts around potential leak points. Using a helium leak detector a.k.a Mass Spectrometer Leak Detector (MSLD) to “pull” the helium into the weld and into the MSLD, which sounds an audible alarm if a leak is detected.
This testing method consists of establishing a magnetic field in the part to be tested, applying magnetic particles to the surface of the part, and examining the surface for accumulations of particles that indicate discontinuities. A magnet will attract magnetic particles to its ends or poles, as they are called.
MIG welders are among the best type for beginners, as they're designed with a wire welding electrode on a spool that is fed at a pre-selected speed through a welding gun. As a semi-automatic or automatic process, gas metal arc welding (GMAW or MIG), is the easiest to learn.
(d) During construction, at least 10 percent of the girth welds made by each welder and welding operator during each welding day must be nondestructively tested over the entire circumference of the weld.
All weld metal testing — This involves testing only the weld metal of a sample welded test plate. It's a standard test for filler metals and in some procedure qualification processes.
An edge joint is the weakest type of weld join, so isn't suitable for load-bearing jobs. Instead, it's ideal for reinforcing metal and replacing worn and damaged metal.
At first, it may be intimidating, but after throwing a few sparks, welding is not difficult to learn. It will however take years of practice miles of weld beads to be truly great at it.
The highest paying welder jobs are in industrial construction. Pipe welders, tube welders, rig welders, underwater welders and combo welders are the highest paid of all welding jobs. The type of welding is important and so is the industry. The top welder salary can be over $200,000 per year in industrial construction.