Development of portable auto peel strength tester for the field coating for welded joints of 3PE pipelines

Epoxy primer plus heat shrinkable tape is basically used for the field coating for welded joints of 3PE anti-corrosion coating pipeline. Peel strength test is the main way to evaluate the effect of welded joint coating. For this purpose, spring scale is usually applied now, but it can not accurately control the speed and angle of peel, neither inspect the welded joint at all positions. Accordingly, the stretching and angle control system of test equipment is optimized on the basis of the theory that the angle of isosceles triangle structure is adjustable. Combining with the system operating software written by the modular design concept, a portable peel tester is developed finally. This product can control both speed and angle of peel strength test of 3PE coating, but also directly measure the pull. Its triangular structure tallies with the required 90° peel angle, and the rated peeling speed of 10 mm/min is achieved by two speed-controlled stepping motors. The test result shows that the tester realizes a dynamometry precision up to 1%. So, it can be used in the engineering test evaluation.