Butt seam vacuum box
The Butt Seam Vacuum Box is a type of vacuum box from MR Chemie designed for leak testing of butt seams that are located around the circumference (circumferential seams) of pipes or tanks. It is typically used when the weld is around the entire pipe bend or cylinder weld – e.g. for pipe sections with welds that surround the diameter. The vacuum box covers the weld seam and seals around it to test for leaks under pressure under the glass plate of the box.
Key features and benefits
Available in many diameter sizes (DN standard) so that the box can be adapted to different pipe dimensions.
Lengths ("economic lengths") between approximately 500 mm and 750 mm, depending on diameter and use.
Includes inspection glass (“sight glass”) that is robust and flexible, so that bubbles/leaks can be observed.
Soft rubber strip/sealing strip around the glass to ensure a good seal against the pipe surface.
Valve with adapter (conical or standard) for connecting vacuum hose; the valve can be sealed at different angles.
All models have a built-in vacuum gauge to ensure that the correct vacuum level is maintained during testing and to avoid misinterpretations.
Technical specifications
Diameter selection: from DN 100 to DN 1600 – i.e. pipe diameters from approx. 114.3 mm up to approx. 1626 mm.
Length: approx. 195 mm for DN 100, and length increases with diameter, up to approx. 730 mm for larger diameters.
Butt weld only – the box covers the entire circumference of the weld.
Standard “economic” lengths between 500-750 mm for most large diameters, shorter lengths for smaller diameters.
Areas of application
Leakage inspection of fully welded pipe joints (circumferential butt welds) in tanks, pipelines and cylinder structures.
Applications where the weld is not accessible from both sides, but only the outside can be inspected.
Laboratory and field use, where visual detection via bubble test requires good sealing and observation through glass.
Industrial maintenance control – for example in pipe installations, flowing pressure vessels, tanks and ships, especially where leak control is safety or environmental critical.