The High Density Polyethylene Liner Installation Method can be routed into the existing pipe using two techniques. However, sometimes it is necessary to use both techniques together to speed up the project phases. Push and pull techniques are the most common in this matter used to keep the covering in place. In the push technique, for watertightness it is necessary to introduce a gasket for a connected profile tube. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay This method consists of some devices such as cable and winch. The arrangement of the winch with the cable pulled into the existing pipe for the sliding lining. The cable is fixed with the segment on the other side and the cable with the polyethylene jacket must be pulled through the existing or host pipe with the help of the winch arrangement. The cable is fixed with this arrangement to bring the pulling method into the right position. To facilitate this pulling technique a pulling head is required to connect the cable. There are different types of traction heads available in the market. Types may vary from project to project depending on the nature of the working conditions and site environment. It also depends on the budget of the project, especially in the installation process. Among them, the cutting-edge footage liner fixed with a main center bolt on one side and the liner on the other end is the most elegant pulling head. A steel pull head is connected to the liner with the help of some bolts. The main purpose of this head is to ensure uniform loading on the cladding wall. The conical shape of the pulling head facilitates the passage of the new tube through the host tube. It also adjusts small deflections in coverings. The diameter of this head must be equal to the liner diameter or less than the outside diameter (OD). This helps pull the tube smoothly when inserted into the host. Due to the tensile process, stretching may occur in the polyethylene coating. For this reason, it is recommended to let the liner sit for at least twenty-four hours after stretching. The polyethylene liner should be extended 3-5% further than the existing traction to maintain safety due to the reduction instinct when returning to its normal position (PPI, 2008). In large diameter and heavy welded joint connection lining, this process may not work well, as well as in longer piping system. A bent strap is installed around the wall of the liner which helps to push into the host. Construction vehicles such as hoe or tracked hoe are used to pull the pipe and push it in the right direction through the pipe. Sometimes other equipment is used to push the liner. The vehicle strokes the hose after connecting it to the belt. The strap must be placed in place after each stroke. The positioning of the strap is done manually. The entire process can be completed with the help of the combination of a front-end loader and a bulldozer. In this process the seal tube is used to create the correct position and ensure leak-proof conditions. This system does not require any cables or hoists to push the liner through the existing system. However, due to the nature of the project or other circumstances, it is sometimes necessary to apply push and pull techniques simultaneously. This technique is most efficient when the polyethylene liner is pulled through a hostlarge diameter where heavy pulling tools are needed. The speed of the push or pull flow is not the same in the entire system. The flow rate when placing the line in the system is different from the flow in the pipe as it moves through the host. It is recommended to keep the flow velocity in the entire system at a level that does not exceed 50% of the pipe capacity. When the liner is placed in the annular space of the host, provide sufficient flow to transport the liner. At the end of the liner system, upstream block flows need to be controlled to avoid flooding. Pumping station, flow control equipment, bypass system mitigate and control the flow system during this technique. There are several types of methods for connecting laterals and house service with cladding. Connection types depend on the properties of the lining and lateral line. When the liner crosses the host line, restoration work begins after a certain time. Since polyethylene has the instinct to expand by pushing or pulling and returning to its original position while at rest, for this reason it is necessary to begin restoration work 24 hours after the liner has been installed. Connection of the pressure hose line made with a rated pressure hose line. This type of connection requires the ability to withstand full pressure. A polyethylene branch saddle is placed on top of the liner hole that connects to the sideline. The connection is made using T-fittings or branch saddles for gluing the side walls with connectors. Sometimes coil pieces are inserted using the electrofusion process. The existing pipe is removed from the connection point to connect the laterals. When connected to the laterals with HDPE, the line joint must be secured using a wraparound saddle. In gravity pipes, a stainless steel clamp is used which is positioned at the connection point of the liner with a gasket. The saddle base and liner are then welded to confirm the integrity of the joint. Subsequently, the flexible joint is used to connect the service lateral with the new polyethylene pipe. The service saddle method is common in gravity piping where steel gaskets and clamps are used. Reconnection of new valves and existing pipe at the end of the project: Reconnection with the existing pipe is the final stage of the slip lining process where the connection is made using fittings and flanges. Reconnection of the piping system can be done by the thermal fusion method or by mechanical fittings. The connection must be made in such a way as to reduce the concentrated load on the joint. There are several types of techniques that reconnect the system confirming the continuation of the existing pressure flow. Connection methods may vary depending on the pipe diameter of your system. In pressurized pipe networks, the connection is made using some specific accessories. Fusion technology is used to reconnect the pressurized hose. There are three methods in casting technology commonly used to attach the cladding to the existing system. In addition to butt, saddle and butt casting, the electrofusion method is also used with the help of saddle joints and fittings. The fusion system bonds the liner and existing pipe surface using heat at a specific temperature and force. This method keeps the joint area structurally sound and provides leak protection. The system is ready to operate as soon as.