Abstract: An inflatable bag is inserted through a small orifice in the side wall of a submerged, liquid-containing hollow member to be radiographed. The inflatable bag is directed to a chosen location within the hollow member, where it is inflated, displacing the liquid from the chosen location. A penetrating radiation source is securely positioned externally on the side wall of the hollow member so that penetrating radiation emanating from the source will traverse the chosen location within the hollow member. Imaging means is securely positioned externally on the side wall of the hollow member so that the chosen location within the hollow member is between the penetrating radiation source and the imaging means. After the radiograph has been made, the inflated bag is deflated and withdrawn from the orifice, following which the orifice is sealed, and the penetrating radiation source and imaging means are removed from the hollow member.