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

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Measurement -- Center of manhole to center of manhole plus 5 feet to ensure the liner never inverts all the way to the end attachment where the holdback rope and lay flat circulation hose are connected. Longer turn-backs result in poor circulation at the downstream end of the cured-in- place pipe and can produce soft ends and/or lifts along the bottom of the liner. End Piece Attachment - “Soft Ends” are purchased from the liner manufacturer and installed on during fabrication of 15” diameter liners and greater. This consists of a handle, constructed of rope covered in tubing and polyurethane, is stitched and adhered on the liner. This will seal the end of the liner. NOTE: The following is a summary of a recommendation by National EnviroTech Group, L.L.C. to use on small diameter liners. The end piece consists of a short piece of 1-2 inch pipe several inches long with caps attached to each end. The end caps on the end pieces should have holes in each end so that any trapped air may be released from the center of the liner as it inverts into the resin saturated tube. Attach a small one way valve to the end piece to allow air to flow out and prevent water from forcing its way back into the center of the installed liner. Place a short section, approximately 2 ft. in length, of rigid hose through the one way valve into the liner. Note: The outside diameter of this hose must be small enough to fit through the one way valve. About 4 - 6 inches of this hose should stick out of the one way valve. If hold-back ropes are tied around the end of the liner, it could possibly cut off the air being released. This section of hose will allow trapped air to be released from the liner in this situation. Alternatively, a piece of heater hose equivalent in length to the standpipe plus five feet may also be attached to an appropriately sized nipple on the end piece. This allows the liner to completely submerge to the bottom of the standpipe forcing air out the heater hose. End Piece Size Recommendations End Piece Diameter Liner Diameter 1.5” 8" - 12" Place the small section of rigid hose in the end piece. The end piece should be centered in the liner, and just slightly inside, such that some liner extends beyond it. Fold the portions of the liner on either side of the end piece in a zigzag serpentine manner and gather it at the nose piece. Place a single wrap of thin felt about 2 inches wide around the area to be banded in the center of the end piece. This will protect the liner from being cut by the banding straps. Band the liner around the end piece with at least two 3/4" stainless steel doubled banding straps for small end pieces and three for larger tubes using larger end pieces. Properly banding the liner is critical in order to prevent water from leaking between the liner and the end piece. Complete the procedure by making several wraps with black electrical tape around the bands and buckles to make sure there are no sharp edges that could damage the liner while the end piece moves through the tube during inversion. Attachment to Top Ring -- Pull the liner through the top ring and/or column making sure that there are no twists. Check for twists by inspecting the location of the seam to insure it goes into and out of the top ring in the same position. If the inversion initially proceeds very slowly then stops and does not proceed any further and it is suspected that the liner may be twisted, pump the water out of the column and liner and remove the liner and start over again. If the liner becomes too large to clearly identify its orientation (i.e. top, bottom, and sides) with respect to the cone, it should be marked before pulling through the top ring. This may be done by numbering the liner 1, 2, 3, 4 starting at the top and proceeding around the tube. Turn the liner back over the face of the top ring ensuring that all folds are evenly spaced around the full circumference. Ensure that the numbers are approximately lined up at the top, bottom, and sides of the face of the cone face.