Hydrotest apparatus

Claim 1

Removable end-closure structure for sealed application to the end of a pipe of given outside diameter for hydrostatic pressure-testing the pipe, said structure comprising a split ring having a cylindrical inner surface of substantially said diameter for mounting to the outer surface of the pipe near an end of the pipe, said split ring having a conical outer surface to be oriented with outward divergence in the direction of the pipe end to be closed, a circumferentially continuous anchor ring having a conically tapered bore of substantially the slope of the outer-surface taper of said split ring and adapted for convergent inwardly compressing coaction with said split ring upon axial displacement of said anchor ring in said pipe-end direction, a first or closure plate of diameter to lap the end of the pipe but less than the outer diameter of said anchor ring, said closure plate being adapted for circumferentially continuous axially abutted sealing engagement with the end of the pipe, said closure plate being characterized by a circumferentially continuous rabbet containing circumferentially continuous locally yieldable gasket material at least in the annular radius range of pipe-end contact, said rabbet being radially outwardly open, a circumferential strap peripherally secured to said closure plate and axially spanning the rabbeted region, a second or back-up plate of substantially the outer diameter of said anchor ring, lost-motion retaining means coaxially retaining said plates within a fixedly limited maximum axial offset of said back-up plate from said closure plate, axially adjustable tie means between radially lapping regions of said anchor ring and backing plate, and fluid-pressure operated means interposed between said plates for pressure-loading said plates for their axially separating relative displacement within said axial offset and in the direction of approach to the maximum of said axial offset.