ABSTRACT
Vacuum box testing is a practical technique of testing in comparison to quantitative measures used to examine objects. Vacuum box testing can be used to test objects on which a pressure differential can be created across the area to be examined. Common application areas of vacuum box testing include piping systems, pressure vessels, and storage tanks. There are various types of boxes or frames used in vacuum box testing depending on the application area and its configuration. Vacuum box inspection can be carried out on lap welds, butt welds, and fillet welds. These vacuum boxes are used to examine a small and specific portion of a welded area to produce accurate results. Vacuum boxes used in vacuum box testing are fabricated of thick, clear Perspex with a closed cell foam seal along the bottom edge. A vacuum gauge and hose coupling are fitted in the box before the testing begins. Then a soapy solution is put on the line of the welding of the object under test. After that, the vacuum box is placed over the testing object, and a vacuity is created inside the box. The object is then observed for either a drop in vacuum or a bubble formation on the surface, in which case the weld is considered defective.
