A number of testing machines specifically designed for the testing of pipes.
Pipes transport granulated materials, liquids, and gases, both aggressive and neutral in nature. They are used in wide variety of environments, including nuclear power stations, in and above the ground for transporting oil and natural gas, in engines for fuel delivery and exhaust gases, and in the chemical industry for producing raw materials. This causes them to be manufactured from the most diverse range of materials and alloys, using various production processes.
Tensile tests
The methods used to test tensile specimens taken from or consisting of pipes vary according to the product form. Small, thin pipes are crushed at the ends for a sufficient length and then pulled, while cores are used in larger diameter pipes to prevent pre-damage through crushing. With larger pipes, standardized specimens are produced from material removed from the wall of the pipe. It is possible that specimens (taken longitudinally) may display the curve of the pipe radius; for reliable, pre-damage-free testing this radius should be compensated for with suitably shaped counter pieces.
Hardness tests
Hardness testing on pipes and large pipes are performed primarily to examine two aspects: Testing of weld seams and determination of the basic hardness of the pipe.
Compression tests
Crush tests are carried out on pipes to test their strength and ductility. These characteristics can be of considerable significance in situations where the integrity of pipework must not be affected by earthquakes, especially when pipes are laid directly in the ground.
Tube-flattening test
For the tube-flattening test, a ring is taken from a tube. The ring is compressed to a defined distance between two compression platens using a testing machine. The position of the weld seam is alternately at a 90° angle or parallel to the compression platens so that the weld seam is subjected to tensile load once on the inside of the tube and once on the outside of the tube.
Drift expanding test
In the drift-expanding test, a conical mandrel is pressed into a tube specimen via materials testing machine according to the tube’s inner diameter and the tube is expanded. The test is ended when the value of the expansion defined in the specifications has been reached. The test is considered passed if no cracks are detected in the tube or at the welded seam after the test.
The drift-expanding test is normally performed on tubes having an outside diameter of 150 mm and a wall thickness no greater than 10 mm. For tubes without a detectable welded seam, the drift-expanding test is used as a replacement for the tube-flattening test.
Flanging test
To perform the test, the end of a tube specimen is formed into a flange with a corresponding tool until a flanging angle of 90° is achieved. The test is considered passed if the outer diameter of the flange reaches the value defined in the specification standards without crack
formations in the weld seam or the tube.
The flanging test is normally performed on tubes having an outside diameter of 150 mm and a wall thickness no greater than 10 mm.
These materials testing machines feature a wide measurement range, which allows for precise determination of even low test loads, without the need to convert the testing machine.
The AllroundLine is our customizable and extremely versatile testing machine. It is available as a floor-standing testing machine and as a table-top testing machine.