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Western Dam Engineering <br /> Technical Note <br /> <br /> May 2016 <br /> <br />12 <br />Prior to Installation <br /> Inspect the pipeline to determine if the pipe is <br />clear of toxic materials in accordance with <br />local, state, and federal safety regulations. <br /> Clean the pipeline with hydraulically or <br />mechanically operated equipment and clear <br />the pipeline of any debris. <br /> Perform a second inspection when the pipeline <br />is clean, to determine the location of any <br />conditions that may prevent proper <br />installation, including: <br />o Seepage inside the pipe <br />o Protruding objects inside the pipe <br />o Crushed or collapsed pipe <br /> Figure 2 – Inversion Installation Method [5] <br />Inversion Method <br /> The CIPP liner is shipped inside-out with the <br />resin already impregnated. Once on site, it is <br />then attached to an inversion standpipe so a <br />leak proof connection is created. The smooth, <br />un-impregnated side if left on the outside for <br />ease of handling. <br /> Then, either air, steam, or water is pushed into <br />the CIPP liner, inverting it (turning it inside- <br />out) and pushing it into the host pipeline for its <br />entire length. Once inverted, the resin side is <br />directly against the inside of the host pipe, and <br />the smooth side is in the flow area. <br />Compressed air is typically used for inversion <br />in the steam curing application and water is <br />typically used in the hot water curing method. <br /> The CIPP manufacturer determines the <br />minimum and maximum air or water pressure <br />required to push the CIPP liner tight against <br />the existing pipe without damaging the fabric <br />tube of the CIPP. <br /> Inversion is the most common installation <br />method, and water is the most common fluid <br />used to invert the liner. <br /> Figure 3. CIPP liner exiting from an existing conduit <br />via the hydrostatic inversion method [5] <br />Pulled-in-Place Method (also called Winch-in- <br />Place) <br /> Pulled-n-place liners are typically used for (a) <br />short, large diameter pipes, (b) long CIPP runs <br />where inversion pressures would be overly <br />high, (c) where inversion equipment would <br />have difficult access, or (d) for UV light cured <br />resin applications. <br /> A pulling tape or cable is first threaded through <br />the host pipe. (This process has its own set of <br />challenges!) The CIPP liner is attached to the <br />cable or tape and to a winch or other <br />mechanically operated device to pull the lining <br />in place.