Award Bid - 2024 Sewer and Manhole Rehabilitation Proj No. 122-019 - Visu-Sewer, LLC

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the circulation hose will tend to float as a result of the hot water and entrained air in the circulating pumps. Weights should be placed every 12-15 feet. Six-ounce fishing weights or several pieces of large chain link can be tied with the same rope used for splicing the hose. Offset holes punched for attachment of the weights and those placed in the discharge hose for increased water circulation. Insure all sharp edges are removed from the links of chain. Failure to weight the hose may result in poor heating along the invert of the installed liner which could require an extended cure cycle or produce an uncured section of liner. Number of Circulation Hoses -- As the diameter and length of the rehabilitation increases, the need to increase the circulation within the tube becomes a necessity. In general one should consider using two circulation hoses for any tube that is 18 inch in diameter or larger. This can be accomplished by attaching two circulation hoses onto the end of the liner. One hose is then attached to the output water from the heater truck and should have no perforations with the end open to allow all the water to output to the end of the tube. The second lay flat is allowed to have multiple perforations as described previously. However, this second hose should be partially (i.e. 50%) closed at the end in order to force more water out the holes punched along the length of the hose. This second discharge hose is not weighted. This circulation hose should be attached to a separate pump (capable of pumping high temperature water) that is simply pulling the water out of the column and returning it throughout the length of the lining tube. WATER COLUMN CONSTRUCTION Top Ring -- The top ring may be any number of diameters depending on the size and construction of the top ring and cone. The top ring can be constructed of carbon or stainless steel. The outer surface of the top ring must have several protruding beads welded around the full circumference at evenly spaced intervals of approximately 1.5 - 2 inches (38 - 50 mm). The beads should be at least 0.125 inch high and a minimum of three beads per end is recommended. These welded beads are necessary to attach liner such that it can slip off during the installation. All the metal surfaces must be completely smooth and free of burrs or sharp edges that might cut or damage the circulation hose(s) or the liner being inverted. Column Height & Diameter -- Guidance for the lengths can be calculated to give recommended water column height based on the diameter and thickness of the liner to be installed. Variable diameters must be manufactured to accommodate the diameter of the liners installed. For example, a top ring may be constructed with a 7.0 inch diameter at the face where the liner itself is attached. The 7.0-inch face would accommodate the installation of 8-10 inch diameter liners. Allowing the column to be a larger diameter makes room for the suction and circulation hose, as well as a plate mold for sampling purposes. For 12” diameter liners, use a 11” diameter bottom ring. For larger than 12” diameter liners, use the liner itself for the downtube. LINER Handling and Storage -- Always protect the liner from anything that might produce holes in the membrane. This includes walking on the hose, dragging it across the road etc. Holes or weak areas may result in a large tear once the liner is stretched with hydrostatic pressure. Also take note that the liner loses strength and is further weakened with heat from the hot water so damaged areas may not become apparent until fully into the curing cycle.