Abu Dhabi Gas Liquefaction Company Ltd Job Training Mechanical Technician Course Module 9 Compressors
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- Figure 4.27(a)
- Strip or channel valves
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Plate, disc or ring valves are used for high-pressure applications. They work in a
similar way to poppet valves but the closing elements are circular rings (the 'discs'). They open when the gas pressure difference provides a force greater than the spring force as shown in Figure 4.26. Gas entering through the upper body forces the valve discs down against springs. The gas then passes between the valve discs and the valve seats and out through the lower valve body, as shown to the right of Figure 4.26. The springs are located in plastic cups. This stops any pieces of broken spring entering the cylinder if the spring breaks. The rings may be joined together, as shown in Figure 4.27(a) or separate, as shown in Figure 4.27(b). Figure 4.27: Valve Rings Figure 4.26: Disc Valve Upper body Lower body Plate or rings Springs Valve seat Gas pressure (opening) Spring force (closing) Plastic cup Gas pressure (closing) Flow direction Gas flow through open valve Personnel & Training Division Job Training—Mechanical Technician Compressors/Rev. 0.0 Page 36 of 90 Strip or channel valves are the cheapest and most common for standard applications. The closing elements are channel-section strips that are held normally-closed by leaf springs. Figure 4.28 shows an exploded view of a channel valve. The port plate and the seat plate fit together with their openings lined up. The channels fit over these openings and are held down against the seat plate by the leaf springs. The springs fit inside the channels and are held in place by the stop plate. Gas enters through the port plate and pushes the channels up off the seat plate against the springs. It then passes out through the openings in the stop plate. Strips of self- lubricating material in the channels stop metal-to-metal contact between the channels and the valve springs. Figure 4.28: Channel Valve Stop plate Leaf springs Channels Guides Port plate Seat plate Valve assembly with stop plate removed Flow direction Personnel & Training Division Job Training—Mechanical Technician Compressors/Rev. 0.0 Page 37 of 90 Suction valve unloaders (double-acting cylinder) Discharge valves Download 0.5 Mb. Do'stlaringiz bilan baham: 
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