 Hello friends, myself Dr. Narendra Kartikar, Assistant Professor, Department of Mechanical Engineering, Valachandra Institute of Technology, Solapur. Now we are going to present and discuss about the study of gating system. At the end of this lecture or the session, student will be able to understand the gating system, its different types and also know where to apply it. The content flow for this presentation, introduction, elements of gating system, gating, then types of gating system, the riser, why risers are required and different type of risers. Let us have a look on the schematic diagram of casting mold. This is the schematic diagram which explains the typical components of two parts sand casting. You can see the cove half, drag half where the particular elements of molds are there like a sporing cup, sprue, gating system, mold cavity, core, core print and riser. The section diagram of casting molds typically is shown on the screen where once again you can have a look across sectional details of that particular casting mold. The cove half, drag half, open riser as well as the vents are shown over there. The pouring basin rather cup is shown, the material poured through the pouring basin flows through the sprue where it passes through the gate and choke, further moves from runner to the mold cavity. There are different type of risers shown over there, open riser, blind riser. The flask is also shown over there, the parting line and sand is also present over there. When we discuss about the casted part, the casting which is solidified and taken from the mold box is looking like this. The pouring cup, the sprue, runner, gate, side riser, casting and top riser. This particular figure shows a one integral solidify element present over there when we broke down the particular sand mold box. Now after visualizing and understanding the cross section of molding box solidified gating system interconnected singular solidified casted part, let us move with the elements of gating system. The particular figure shown on the screen elaborates the gating system itself. The elements of gating systems are pouring basin, drown sprue, sprue base, runner, extention, gates. The dotted portion shows over there is nothing but a casting geometry. The particular elements interlinked one with the other are shown in a three dimensional isometric figure over there. Now exactly what the meaning of gating, gating are the flow passes to run and feel the molten metal in the mold cavity. Gating system include distribution of clean metal with the proper rates and velocities at specific location in the mold. Let us have a look on the types of gating system. Top gate, bottom gate, branch gate, horn gate and parting type. Let us see one by one the different type of gate. Initially the top gate, the figure shown on the screen is self-explanatory will deliver the more elaboration for the top gate itself. The cope half drag half parting line cavity is seen over there. Typically sand and pouring cup ladles are also shown over there. Molten metal from pouring basin is fed directly into the mold cavity. The hottest metal remain at the top of casting. This promotes directional solidification from the casting towards the gate. Second type, bottom gate, the molten metal enters from the bottom to the mold cavity. It is more clarified with the figure shown on the screen. The molten metal runs through the sprue, further runner, further ingate and then it ends entered with the cavity itself. The sand, sprue, cavity, runner, ingate, cope half drag half are the elements shown in the figure. It minimizes the turbulence and erosion in the mold cavity, provides unfavorable temperature gradient that do not promote directional solidification. Horn gate, you can see over here the particularly section of horn gate. This type of gate which is a part of pattern with a smooth curves and progressive change in dimension is designed to minimize mold erosion and oxidation of molten metal. You can see over here the particularly more self-explanatory diagram shown on the screen. Parting type, it is the most commonly used gate and it is a compromise between top and bottom gate. The gate is provided at the parting line of the mold that is very clearly visible with the means of diagram shown on the screen. The particular parting line is present over there where the gate is going to be generated and it interlinks the sprue and particularly mold cavity itself. Typically, the cope, drag and sprue as well as riser along with the core elements are shown in the diagram. This is one of the real-time image which explains more elaborate on the visualization of riser being a present over there for casted element. You can see the left side element is a solidified element which is taken out from the particular mold box and after finishing the ready part is looking like on the right side of the image. At this stage of this session, are you able to recall, share some of about effect of shrinkage in a journey of molten metal till it solidified with reference to your earlier gained knowledge just enlist few of the points. Now let us move further why the risers are required. The shrinkage occurs in three stages over there while solidifying the molten metal. When temperature of liquid metal drops from pouring to freezing temperature. When the metal changes from liquid to solid state and when the temperature of solid phase drops from freezing to room temperature. The shrinkage for stage 3 is compensated by providing shrinkage allowance on the pattern while the shrinkage during the stage 1 and 2 are compensated by providing riser. Now let us see about the riser. During solidification metal experience shrinkage which results in void formation. This can be avoided by feeding hot spot during solidification. Risers are used to feed casting during solidification. So few of the images just to get the aware about the riser. Type of risers. Open riser. The top surface of the riser will be open to the atmosphere. The open riser is usually placed on the top of the casting. Gravity and atmospheric pressure causes the liquid metal in the riser to flow into the solidifying casting. The image is self-explanatory more elaborative for the type of riser, open riser. Blind riser called as blinder riser also. It is completely enclosed in the mold and not exposed to the atmosphere. The metal cools lower and stay longer promoting directional solidification. The liquid metal is fed to the solidifying casting under the force of gravity alone. Here once again the image is more self-explanatory with the presence of all the number of varieties of elements over there. It is about the blinder riser. References for these presentations are Introduction to Basic Manufacturing Processes and Workshop Technology by Rajendra Singh. A textbook of Workshop Technology Manufacturing Processes by Khurmi Gupta. And few more references are as follows. Thank you.