GB1413242A - Ultrasonic testing - Google Patents

Abstract

1413242 Ultrasonic probes BRITISH STEEL CORP 29 March 1974 [30 March 1973] 15401/73 Heading H4J Ultrasonic testing apparatus, for rotation around a steel tube 2 (Fig. 1) or other article to be tested, includes an ultrasonic pulse generating probe 9 having a transmitting face 10 located in a recess 21 extending radially of the axis of rotation. Coupling liquid is supplied to the recess 21 and at least part of such liquid is directed transversely across the probe face 10. Part of the coupling liquid is exhausted from the recess 21 adjacent the face 10, whereby to flush dirt particles from the recess 21. Several probes 9 may be provided and at least some may be spaced circumferntially around the axis of rotation. A pad 1 rides over steel tube 2 and rotates in the direction of arrow 3 as tube 2 moves axially. An inclined guide 4 assists the probe assembly in riding over protrusions on the tube 2. Pad 1 is carried by a block 5 which carries two radially arranged tubes 6, 7. Block 5 has an inlet pipe 13 for water, part of which passes via a port 14 directly into recess 21, whilst part flows through a channel 15 in tube 6 and into the recess 21 at the outer end of tube 6. As water exits from channel 15 it impinges upon and flows across surface 10 and passes out of the recess 21 via four ports 16 in an annular chamber 17 formed in a surrounding collar 18 clamped by a screw 19. Water from chamber 17 exhausts through a bore 20. In use, centrifugal force ensures rapid filling of recess 21 with water, the water establishing acoustic coupling between the tube 2 and the probe 9. Small dirt or scale particles from the tube 2 exhaust through bore 20, whilst larger particles remain in chamber 17 until collar 18 is cleaned. The flow capacity of the outlet 20 is considerably less than the inlet 13. Excess water leaks from the radially inner end of the recess 21 around the tube 2.