Leak & Tightness Testing
For non-destructive material testing
VSP series vacuum leak detectors enable quick and reliable leak testing of weld seams on containers, pipelines, and many other welded structures using the bubble test method.
This testing method can also be used to inspect castings for continuous defects (cracks, porosity). VSP leak detectors and vacuum bells are used in particular for leak detection in cases where test objects are only accessible from one side or when dealing with open structures (for example, in tank bottoms or drip pans). The leak detection limit of the bubble test method that can be achieved under practical test conditions is approximately 10-5 to 10-4 Pa*m3/s (10-4 to 10-3 mbar*l/s).
Vacuum bells
Overlap joint fillet weld vacuum bell
In the testing method used with VSP devices, the area of the weld seam or cast surface to be examined for leaks is wetted with a foam-forming MR® 99 leak detection spray. The test area is then covered with a vacuum bell. The vacuum bell is connected to the leak detector via a vacuum hose and is evacuated in seconds when the valve is engaged.
The fracture-resistant viewing windows made of highly transparent, flexible plastic, adapted to the geometry of the test area, are bordered with profiled rubber and provided with a special soft rubber seal. Freely rotating, arbitrarily oriented sealing valves with a conical connecting piece for the 1/2″ vacuum hose are used to evacuate the vacuum bell.
Under the viewing window of the evacuated vacuum bell, a foam mushroom forms in the event of continuous defects due to the air flowing through at this point. To ensure that even small leaks can be reliably detected, the vacuum under the bell must be maintained for at least 30 s.
VSP leak detectors
In order to place even larger vacuum bells under vacuum practically immediately after placement via a possibly quite long vacuum hose, vacuum pumps with high suction capacities (up to 16 m3/h) are used in VSP leak detectors. For completion to a VSP leak detector, the vacuum pumps are installed together with all additional units in a stable, welded tubular steel frame. Due to their extensive freedom from maintenance and their robust and consistently construction site-compatible design, VSP leak detectors have proven themselves to a particular extent, especially in mobile applications.
