Polyethylene leads all plastics in the volume of resin used each year. They are produced in three types : low, intermediate and high density. All three types have in common the properties of toughness , resistivity to solvents, alkalies, excellent dielectric properties, good colorability , very low moisture absorption and relatively low cost . The polyethylenes are blow and injection - moulded , extruded into very wide range of products which includes house wares such as bowls , plates, dishpans, paint-brush handles, flexible tubing, bags for packaging vegetables , hardware , squeeze bottles etc.,
Steam Pressure at inlet to a steam turbine is reduced by throttling process to maintain the speed of the turbine constant at part load and hence this method of governing is called "Throttle Governing". Construction : Throttle governing system consists of a centrifugal governor, a lever , an oil pump , a pilot piston , control valve , a relay piston and a throttle valve. The throttle valve is moved by a relay piston. The relay piston is actuated by pilot piston control valve. There are two piston valves covering ports in the pilot piston control valve without any overlap. These piston valves are operated by lubricating oil supplied by a gear pump at 2 to 4 bar. The oil returns to the drain from this chamber. Working : When the turbine works on full rated load, the throttle valve will remain open. When the load is decreased, the energy output of the turbine becomes in excess and the turbine shaft speed increases. Hence, governor sleeve will lift. The upward movement of the
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