Testing installation for pipes having an internal testing unit driven by the rotation of the pipe

A testing installation for pipes and rod material to determine surface defects and/or core defects, comprises a plurality of test zones (1, 2) having a rotary roller track (3) for rotatingly driving the pipe (4) to be tested. An internal testing unit (7) is movable lengthwise of the pipe, within the pipe; and parking stations (9, 10) adjustable to the pipe length are provided at both ends of the testing zone for accommodating the internal testing unit during pipe change. An external testing unit (12) is movable along the outer pipe wall (11), and conveying devices (16) for the introduction and removal of the pipes into and from the testing zones are provided. The internal testing unit (7) is a cylindrical housing (21) having built-in contactless testing devices (22) and arranged on a running gear frame (23) with a forward running gear and a rearward running gear (24, 25). These running gears comprise a drive shaft (26) and two supporting rollers (27, 28) assuming a driving position (26' , 27', 28') obliquely to the longitudinal axis of the pipe to be tested and travelling on the inner pipe wall and being driven by the revolving motion of the pipe to be tested.