Vacuum Box testing is used to check for any leaks or fault in the welding of bottom & annular plates of the storage tank. The vacuum pump attached creates a vacuum in the vacuum box, which shows bubbles on the soap water applied on the weld in case of any leaks or faults. This is one of the most adoptive test methods to detect leak or defects and widely used in the bottom plate of Tank, Ships & Barge bottom plates etc.