Device for detecting flooding of a hollow structure

摘要

An inspection device detects flooding in a hollow structural member such as the leg of an oil or gas rig so as to detect the presence of through wall cracks in the member. The device comprises an ultrasonic transducer for transmitting a pulsed beam of ultrasonic sound to pass through opposing faced walls or wall portions of the member and a visual indicator responsive to time spaced echoes of the ultrasonic beam reflected respectively from the opposing walls or wall portions and received by the transducer to indicate the presence or absence of flooding in the member. The transducer is located in the bridge plate of a jig and its beam passes through an aperture in a support frame of the jig. The support frame has a pair of spaced magnetic feet attached to a bracket on the frame and a further magnetic foot secured to the frame, the feet permitting the jig to be clamped onto a steel rig member so that the transducer can be optimally aligned with the member to optimize received echoes. The bridge plate is movable in two orthogonal planes by adjusting control knobs so as to optimize alignment. A further visual indicator also responsive to the echoes from the transducer is adjustable to indicate whether the transducer is optimally aligned and only when the transducer is optimally aligned is the presence of flooding, if indicated by indicator, taken to be valid.