Abstract: A method and apparatus for quickly and inexpensively providing a constant extrusion pressure for pipeline lining with a mortar. A mandrel is inserted in a pipeline section with a slug of mortar ahead thereof. A pushing force is applied thereto to overcome resistance to movement thereof. A constant tension pull is applied to the mandrel to effect relatively constant but effective extrusion pressure between the mandrel and the pipeline wall for extrusion of mortar on the inner wall of the pipeline section.

Abstract: An increased efficiency method and apparatus for lining a section of pipe with a cement mortar. After a wet cement mortar has been applied to a cleaned interior surface of a pipe, carbon dioxide is introduced into the freshly lined section of the pipe in such quantity that a crust of calcium carbonate will be formed on the interior surface of the wet cement mortar lining as the carbon dioxide reacts with calcium compounds of the wet cement mortar in a relatively short period of time. This crust is provided to protect the underlying mortar from scouring, while tolerating a low-velocity flow of water, until the normal hardening of the underlying mortar through hydration can take place so as to substantially reduce the out-of-service time of the section of pipe which is being lined.

Abstract: An increased efficiency method and apparatus for lining a section of pipe with a cement mortar. After a wet cement mortar has been applied to a cleaned interior surface of a pipe, carbon dioxide is introduced into the freshly lined section of the pipe in such quantity that a crust of calcium carbonate will be formed on the interior surface of the wet cement mortar lining as the carbon dioxide reacts with calcium compounds of the wet cement mortar in a relatively short period of time. This crust is provided to protect the underlying mortar from scouring, while tolerating a low-velocity flow of water, until the normal hardening of the underlying mortar through hydration can take place so as to substantially reduce the out-of-service time of the section of pipe which is being lined.

Abstract: An improved method for lining a section of pipe with a cement mortar. After a wet cement mortar has been applied to a cleaned interior surface of a pipe, carbon dioxide is introduced into the freshly lined section of the pipe in such quantity that a crust of calcium carbonate will be formed on the surface of the wet cement mortar lining as the carbon dioxide reacts with calcium compounds of the wet cement mortar in a relatively short period of time. This crust is provided to tolerate a low-velocity flow of water to protect the underlying mortar from scouring until the normal hardening of the underlying mortar through hydration can take place so as to substantially reduce the out-of-service time of the section of pipe which is being lined.

Abstract: The present disclosure relates to a so-called drag trowel which is drawn through a pipe or the like to trowel a layer of mortar or other plastic lining material therein. The trowel is frustoconical, having a small leading end of relatively fixed diameter and a larger trailing end which is adapted to expand and contract in the direction of its diameter. The present disclosure provides a novel means within the trowel for exerting a resilient expansive force thereagainst in a circumferential direction fairly close to the large end of the trowel. The expansion means comprises resilient means extending lengthwise along the inner surfaces of the trowel with means for translating the force of the resilient means to a circumferential expansive force and with means for adjusting the effective force of the resilient means.

Abstract: The invention relates to a frustoconical drag trowel which is drawn through a pipe or the like to trowel a layer of mortar or other plastic lining material therein. The frustoconical trowel has a small leading end of relatively fixed diameter and a large trailing end which is adapted to be expanded and contracted in a diametral direction. The present disclosure provides a novel means within the large end of the trowel for exerting a resilient expansive force thereagainst. This means comprises a hollow torus adapted to bear against the interior of the large end of the trowel along the perimeter of the torus.