1991-01-14 Regular Meeting - Laserfiche WebLink

Browse Search

• • Line Obstructions - If inspection reveals an obstruction that cannot be removed by conventional sewer cleaning equipment, such as heavy solids, dropped joints, protruding service connections or collapsed pipe that will prevent completion of the inversion process, then a point repair excavation shall be made by the City or the City's designated contractor to uncover and remove or repair the obstruction. h. Installation Procedures: Wet Out -The Contractor shall designate a location where the tube will be impregnated ('wvet out") with resin using distribution rollers and vacuum to thoroughly saturate the tube felt fiber prior to installation. This must be done to ensure that there will be no resin voids or weak areas. The Contractor shall allow the City's Authorized Representative to inspect the materials and wet out procedure. A catalyst system compatible with the resin and tube shall be used. Insertion -The wet out tube shall be inserted through an existing marl~ole or other approved access by means of an inversion process and the application of a water column sufficient to fully extend it to the next designated manhole or termination point. The tube end shall initially be turned inside out and attached to a platform ring or standpipe. The inversion water column will be adjusted to be of sufficient height to cause the impregnated tube to invert from manhole-to- manhole and hold the tube tight against the existing pipe wall, produce dimples at side connections, and flared ends at the manholes: The Contractor shall not be allowed to pull the wet out tube in place unless the Contractor can prove that this method of installation does not result in tears or abrasion of the tube and uneven redistribution of resin. Curing -After the insertion is completed, the Contractor shall supply a suitable heat source and water recirculation system capable of delivering hot water uniformly throughout the section to effect a consistent cure of the resin. The curing temperature shall be that recommended by the resin/catalyst system manufacturer. The heat source shall be fitted with suitable monitors to gauge the temperature of the incoming and outgoing water supply. Another such gauge shall be placed between the impregnated tube and the invert of the original pipe at the manhole(s) to determine the temperatures during the resin curing process. Initial cure shall be considered completed when the exposed portions of the CIPP appear to be hard and the remote temperature sensing device indicates the cure period to be of adequate duration as recommended by the resin/catalyst system manufacturer and modified for the inversion process. Cool-down -The Contractor shall cool the hardened CIPP to a temperature below 100 degrees Fahrenheit before relieving the water column. Cool water maybe added to the water column while draining hot water from a small hole at the opposite end of the CIPP so that a constant water column height is maintained until cool-down is completed. Care shall be taken in the release of the water column so that a vacuum will not be developed that could damage the newly installed CIPP. Warranty -The finished CIPP shall be continuous over the entire length of an inversion run and be as free as commercially practicable from visual defects such as foreign inclusions, dry spots, pinholes and delamination. It shall also meet the leakage requirements or pressure test specified below. During the warranty