DETECTION OF LEAKAGE IN HYDRAULIC PRESSURE TEST OF STEEL PIPE AND INSTRUMENT FOR THE SAME

摘要

PURPOSE:To perform a highly reliable test by monitoring the stroke of an intensifier for feeding high pressure water into a steel pipe and detecting the leakage of a minute amount that does not appear in a pressure chart recorder. CONSTITUTION:A magnetic scale 12 and a detecting head 13 are provided on the fixed side of an intensifier 7 for feeding high pressure water into a steel pipe P and on a rod side, respectively. The head 13 rises with the rise of the intensifier 7 while sliding on the surface of the sale 12 and the amount of the stroke of the intensifier 17 is detected by the amount of the movement of the head 13. Oscillation sensors and monitors for observing the operating conditions of the electromagnetic valves of seal portions (p) (p1-p9) are provided on the seal portions (p). When the stroke of the intensifier 7 falls in an abnormal condition, the oscillation sensors and the monitors refer to the presence or absence of leakage in the seal portions. Thus, whether the cause of the leakage exists in the seal portions (p) or in the steel pipe P is judged. Accordingly, the cause of such a minute leakage that does not appear on a pressure chart can be surely determined.