Flanged and dished heads

Faetor for determining the eapaeity (gal) for the bottom head = 0.606 for ASME Standard flanged and dished heads Total heat transfer surfaee area, ft ... 

Referring to the wetted surface, A , the surface areas of ASME flanged and dished head, ASME elliptical heads, hemispherical heads, etc., are often the end assemblies on... 

Using ASME flanged and dished heads (F D) from Appendix Tables of Blanks, the circle size is 152 in. for a 12-ft diameter tank. Then add 3-in. straight flange which becomes 158 in. which is 158/12 = 13.166 ft diameter. Area of this diameter for surface area of head = 136.14 sq ft equivalent surface area of one head. For a horizontal vessel there are two heads possibly exposed to fire. 

Standard dished head AS ME flanged and dished head ... 

Construction In accordance with ASME Code U 68 for Unfired Pressure Vessels all-welded with flanged and dished heads shell thickness 4 iu., head thickness... 

Construction All welded mild steel with flanged and dished heads. Head thickness in., shell thickness 3- in., internal lining in., acid-resistant rubber Connections Manhole 18 in., skimmer 6 in., drains 3 in. (2 required), gauge connections 13- in. 

Construction All-welded mild steel with flanged and dished head head thickness in., shell thickness 6 in. 

Head types fall into one of three general categories hemispherical, torispherical, and ellipsoidal. Hemispherical heads are analyzed as spheres and were covered in the previous section. Torispherical (also known as flanged and dished heads) and ellipsoidal head formulas for stress are outlined in the following form. 

Note D = R for heml-heads D = 0.9D if nozzle and reinforcement lie within 0.8D of 2 1 head D = L if nozzle and reinforcement lie within dished portion of a flanged and dished head. R ... 

Table 5.7 gives the inside-corner radius and radius of dish for code flanged and dished heads. Table 5.8 gives the straight-flange length for different head thicknesses <>f flanged and dished heads. 

Table 5-8. Typical Stondard Straight Flange for ASME-Code Flanged and Dished Heads... 

For eost-eslimating purposes the procedure presented in the previous section for code flanged and dished heads is followed Fig. 5.12 is used for the blank diameter and Table 5.12 and Fig. 5.13 are used for the cost of forming per head for two to four heads. Table 5.10 may be used for determining other quantity diflerentials. 

K = factor for ellipsoidal heads as determined from Eq. 9.6 L = spherical crown radius of flanged and dished heads L = effective length of cylindrical shell L, = effective length of conical section... 

M — factor for flanged and dished heads as obtained from Eq, 9,8 P = pressure... 

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