Expansion bellows

Shall be provided on the shell side (when operating temperature is more). 

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Because of the inherently greater susceptibility of expansion bellows to failure from unexpected corrosion, failure of guides to control joint movements, etc., it is advisable to examine critically their design choice in comparison with a stiff system. 

Both sides of the neoprene or EPDM rubber or metallic expansion bellows. 

Figure 31.4(b) Rubber or metallic expansion bellows for enclosure jointing and end terminations (Courtesy Best Crompton)... 

Fig ure 5-16. Casing and connections are designed to minimize distortions, prevent cracking, and allow relative movement during warmup and cool down. This view of the exhaust casing shows the stainless-steel expansion bellows. 

For higher-pressure boilers demineralization is necessary to minimize total dissolved solids in the boiler. This water is normally carried in steel pipework, but if condensate is returned and the condensate has become contaminated (for example, with carbon dioxide or copper ions) more corrosion-resistant materials such as copper are required. Downstream of the boiler, steam pipework is usually steel with steel or stainless steel expansion bellows. 

Boiler salts can contain chloride ions. When carried over into the steam (e.g. during priming) this can result in chloride stress corrosion cracking of austenitic stainless steel expansion bellows. In steam systems where freedom from chloride cannot be guaranteed, bellows... 

Expansion bellows in the regenerated catalyst stand pipe have been subject to failure. lnconel(e) 625 failed as a result of loss of ductility from an aging reaction that occurs in the 1,100 to 1,500°F (595 to 815° C) range. Incoloy 7 801 (Ti stabilized for resistance to intergranular attack [IGA]) undergoes a severe loss of ductility above 900° F (480° C). Incoloy 800 has been used successfully, although it is not immune... 

Corrosion problems have also occurred in compressors, sour water valve trims, expansion bellows, and hydrocracker fractionators. Type 4140 (UNS G41400) compressor impellers have sulfide cracked in sour gas when the hardness exceeded 235 Brine)i(e>. Hardened 12Cr valve trim has sulfide cracked to prevent this problem, 18Cr-8Ni SS trim in sour water service is commonly used. Sulfide cracking has not occurred significantly in pumps. 

FIG. 10-171 Action of expansion bellows under various movements. (From Kellogg, Design of Piping S) tems, Wiley, New York, 1965.)... 

MSW Feed System, The MSW feed system consisted of a sealed weigh hopper supported by load cells, a 10,2 cm diameter by 102 cm long screw feeder powered by a variable speed DC motor, and a 7.6 cm diameter feed chute fitted with an expansion bellows and a knife gate valve. An air cooler was installed to keep the feed chute near the combustor from overheating. 

Wheel-speed sensors are available with or without (direct connected sensors) cable. Cable routing in the car is important and many types of sensor configuration (cable layout) are possible. Grommets and clips can fix the cable to the car body. Expansion bellows of plastic protect the cable from damage. Fig. 7.9.12 shows a complete WSS consisting of sensor head, connector, grommets, clips, and expansion bellows. The fixture to the car body with clips and grommets is shown in Fig. 7.9.13. 

Fig. 7.9.13 Fixing parts to attach the sensor cable to the car body a) cable clip b) grommet c) grommet d) expansion bellows of plastic for cable protection...

If there is an air preheater, the combustion air will be brought in through an insulated duct to avoid heat loss and to protect the operators. It is important tiiat such ducts be provided with expansion bellows and that the duct be properly tapered to insure an even supply of air to each burner. 

The strain produced by the difference in expansion of the outer and inner walls of a vacuum jacket is reduced if the outer tube is provided with expansion bellows (Figs. 257 b, 282), or the inner tube with an expansion coil. If the column has diameter of less than 10 mm and a length of more than 500 mm, or if the temperature exceeds 150 °C it is advisable to wind an electric heating tape around the outer wall of the vacuum jacket. A rough estimate of whether the insulation is sufficient can be obtained by feeling it the outer surface should not be appreciably above room temperature. 

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