Part :Fill the following blanks (20 points)

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1 Part :Fill the following blanks (20 points) 1. Among the impurity elements in carbon steel, ( ) are useful elements, ( ) are harmful elements. 2. The plastic properties of metal materials are ( ) and 3. The higher the temperature of carbon steel, ( ) its strength properties, ( ) its elastic modulus. The designations σ b and σ s stand for ( ) property. The designation HB stands for ( ) property. 5. For carbon steel, the value of Poisson s Ratio 6. Among killed steel, semi-killed steel, and boiling steel, ( ) is of the best properties. 7. The common heat treatments of steel are ( ), ( ), and 8. The content range of carbon element of low carbon steel is 9. For ordinary steel, the content of S,P must be less than ( ) respectively. 10. According to pressure to which vessels are subjected, for normal pressure vessels, the pressure range is ( )MPa, for low pressure vessels, the pressure range is ( )MPa, for medial pressure vessels, the pressure range is ( )MPa, for high pressure vessels, the pressure range is ( ) MPa. 1

2 11. For a rolled cylinder, its nominal diameter is its ( ) diameter. 12. The basic parameters of standardization of pressure vessel parts are ( ) and 13. For an axial symmetry shell subjected to uniform pressure, the entire finite section equilibrium equation is ( ), the shell element equilibrium equation is 14. The edge stress characteristics are ( ) and 15. Nominal Thickness is the sum of ( ) thickness plus ( ) tolerance for steel materials, which then ( ) to the nearest thicker value of thickness given in material specifications. 16. The strength theory that we use to design pressure vessel is the ( ) strength theory. 17. The welded joint efficiency is related to ( ) and 18. The purposes of hydrostatic test are to exam ( ) and ( ) of a whole vessel. 19. For a standard elliptical head, a/b = ( ) is determined. 20. If the maximum working pressure of a vessel with a safety valve is 2.5 MPa, and its working temperature is less than Usual failure forms is ( ) for an internal pressure vessel. 2

3 Part II Answer the following problems (50points) 1. (10 points)a heat exchanger is shown in Fig.1. Point out the name and explain the roles of the following parts No. Name Roles Fig.1 2. (8 points)explain the meanings of each designation 1Cr18Ni9Ti Stainless Steel 10.1%(C),1818%(Cr), 99%(Ni) 16MnR 16 R 10g 10 g Q235B Q Mn2VDR 09 2 D 2Cr

4 3.(14points)Write the formulae of R1 and R2 corresponding points of the following shells and their stresses σ θ, σ when subjected to internal pressure P,and the thickness is m Point R 1 R 2 A σ m σ θ B C D On the line of AB On the line of BC On the line of CB On the arc of CD On the arc of DC On the spherical segent α Fig. 2 4.(8 points )Draw a sketch of bolted flange connection with Tongue and Groove contact facing. Point out names of the main parts. 4

5 5.( 5 points) Draw a sketch of fixed tubesheet heat exchanger with 4 tube side passes, draw the flow order, the positions of front channel partition plate and rear construction partition plate. 6. (5 points)explain the reason why expansion joint can decrease the thermal stress of fixed tubesheet exchanger.assume the force of expansion joint is: F = k l Part III :Calculate (30 points) 1. ( 10 points)examine the stability of the vacuum vessel at 300.Assume C 1 =0.8mm, C 2 =1mm and calculated length L=6000mm.The other conditions are given in Fig.3. Material 16MnR, Standard elliptical heads. Fig (10 points)a pressure vessel of 16MnR with an inside diameter 2000mm is subjected to an internal 5

6 pressure of 4.0MPa,and it was equipped with safe valve. For 16MnR, allowable stress is 147 MPa at design temperature (250), yield stress and tensile strength are respectively 325MPa and 490MPa at normal temperature. Assume all seams are double-welded butt joints and are full NDE, C 1 =0.8mm and C 2 =1mm. Determine the thickness of the cylindrical shell and the standard elliptical heads, and verify the strength in hydrostatic test. 3. (10 points)find the maximum compressive stress and the maximum tensile stress of a tall column at section22 and section11(shown in Fig.4). Assume s e =10mm and D i =1200mm, and the others are given as follows: Operating State Notoperating state Section Internal Pressure P (MPa) Longitudinal stress due to gravitational force σ 2 (MPa) σ (MPa) ± 40 ± 30 ± 40 ± 30 3 F Fig.4 6

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