Abstract: A pipe clamp device for the compression of a gasket relative to a pipe joint comprises a clamping ring having interconnectable portions with a peripheral gasket-engaging surface and adapted for disposition around a pipe, connecting devices to connect the ring to an anchor ring to apply a generally axial clamping force to the clamping ring and thereby to the gasket, compression devices operable to cause radially inward contraction of the ring portions and consequent radial compression of the sealing gasket, and a varying diameter inner peripheral surface on the anchor ring to allow use on pipes of various diameters.