ASME Design Equations

BACKGROUND OF THE ASME DESIGN EQUATIONS FOR TUBESHEETS IN U-TUBE EXCHANGERS... 

ASME Design Equations for Ellipsoidal and Flanged and Dished Heads... 

ASME DESIGN EQUATIONS FOR ELLIPSOIDAL AND FLANGED AND DISHED HEADS... 

The necessary wall thickness for metal vessels is a function of (1) the ultimate tensile strength or the yield point of the metal at the operating temperature, (2) the operating pressure, (3) the diameter of the tank, and (4) the joint or welding efficiencies. Table 4 presents a summary of design equations and data for use in the design of tanks and pressure vessels based on the ASME Boiler and Pressure Vessel Code as specified in Section VIII of Division 1. 

Design equations and charts for the various types of domed heads are given in the ASME BPV Code and should be used for detailed design. The code covers both unpierced and pierced heads. Pierced heads are those with openings or connections. The head thickness must be increased to compensate for the weakening effect of the holes where the opening or branch is not locally reinforced (see Section 13.6). 

There are two junctions in a torispherical end closure that between the cylindrical section and the head, and that at the junction of the crown and the knuckle radii. The bending and shear stresses caused by the differential dilation that will occur at these points must be taken into account in the design of the heads. The ASME BPV Code gives the design equation (Sec. VIII D.l Part UG-32) ... 

This governing body has published proper design equations and assigns allowable stress for each of a variety of materials of construction as a function of temperature. In addition to published formulas for common shapes of pressure vessels, the ASME code also provides methodologies to test irregular shapes by evaluating their point of permanent deformation or their bursting pressure. 

Heat exchangers in the United States are normally designed according to the Standards of Tubular Exchanger Manufacturers Association (TEMA) and the ASME Code, VIE. In general, TEMA requirements are a supplement to the ASME requirements, for they tend to include areas not discussed in the ASME. Most of the TEMA design equations relate to tubesheet design when affected by differential pressure and temperature, expansion joints, bustles, and so on. 

Part 3, which consists of five chapters, details the design and analysis of components. Chapters 8 and 9 derive the design equations established by the ASME Code, VIII-1 and - 2, for cylindrical shells as well as heads and transition sections. Chapter 10 discusses gaskets, bolts, and flange design. Chapter 11 presents openings and their reinforcement Chapter 12 develops design equations for support systems. 

The buckling equations developed by Von Karman and Tsien are the basis of the design equations developed by ASME. Von Kantian s equations, which are substantiated by tests, give a more accurate prediction of buckling strength of... 

Today most layered vessels arc constructed in accordance with the ASME Code, Vni-1, Division 2. The majori of the design equations given in the code for solid wall vessels are applicable to layered vessels. For fabrication, the ASME Code, VHI-l, Division 2, gives additional rules for layered-vessel constmetion. One criterion for controlling wrapping tightness of layered shells is that the area of any gap between two adjacent layers, as measured from the end of a shell section, must not exceed the thickness of a layer expressed in square inches. This is illustrated in Fig. 15.7. 

Nikravesh, P.E. and Gim, G. Systematic Construction of the Equations of Motion for Multibody Systems containing closed Kinematic Loops, ASME Design Automation Conference, 1989. 

Section VIII of the ASME Boiler and Pressure Vessel Code provides all of the necessary design equations and should be adhered to for safety reasons when designing vessels larger than 0.2 m. From the ASME Code, the minimum inner vessel shell thickness, for a cylindrical vessel can be determined from... 

ASME s hoop design equation is only based on internal pressure. ASME ignores the contribution of other loads such as the shear force and the torsional moment in generating hoop stresses. As is seen, ISO is a rather more advanced code when it comes to the calculation of effective axial force and effective pressure. 

For the design of internal-pressure cylindrical vessels, the API-ASME Code for Unified Pressure Vessels recommends the following equations for determining the minimum wall thickness when extreme operating pressures are not involved ... 

Design of vessels using equation 13.59 is not in accordance with the ASME BPV Code, and hence can be used only for initial estimates. For detailed design... 

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