Flat heads openings

Unstayed flat heads and covers can be designed by very specific rules and formulas given in this subsection. The stresses caused by pressure on these members are bending stresses, and the formulas include an allowance for additional edge moments induced when the head, cover, or blind flange is attached By bolts. Rules are provided for quick-opening closures because of the risk of incomplete attachment or opening while the vessel is pressurized. Rules for braced and stayed surfaces are also provided. 

This procedure is only applicable for integrally attached flat heads with centrally located openings which exceed one-half the head diameter, For applicable configurations see sketches in ASME Code, Figures UG-34(a), (b-1), (b-2), (d), or (g). 

The method employed in this procedure is to disregard the shell attached to the outside diameter of the flat head and then analyze the flat head with a central opening. 

Side plates, rectangular vessels. UW-13. Appx I3 Opening in fiat heads. UG-39 Welced flat heads. UG-34. UW-i3. ULW-17 Corner joints. UG-93. UW-9.13.18 Cat. S circumferential joints, UW-2.3.9 12 33. 

Procedure 2-10 Design of Large Openings in Flat Heads [1]... 

Reinforcement for openings in flat heads and blind flanges shall be as follows [1, Seetion UG-39] ... 

At maintenance access platforms, adequate space must be provided to swing the maintenance access cover flat e open for storage against the ice of the tower. Tc head-mounted maintenance accesses... 

One of the more common types of closures for pressure vessels is the unstayed flat head or cover. This may be either integrally formed with the shell or welded to the shell, as shown in Fig. 10.1 or it may be attached by bolts or some quick-opening device as shown in Fig. 10.2. It may be circular, obround, square, rectangular, or some other shape. Those circular flat heads that are... 

Flat face flange. Appendix Y. Fig. UA-111Q Welded connection. UW IS. UW 16. Fig. UW 15.1 Opening. UG 35to UG 42, UA 7. UA 280 Multiple openings. UG-42 Non pressure parts. UG-6, UG-22. UG-SS. UG-82 Hemispherical head. Pressures. 

Reactors Assembled cost is 5/lb. Dished bottoms, open tops, height equal to diameter, bottom surface equals 1.5 times the surface of a flat plate of the same diameter. Tanks of over 1500 gal capacity are of 1/4" plate, smaller ones of 3/16" plate. Freeboard equals volume of the dished head. 

A dished head tank of diameter DT = 1.22 m is filled with water to an operating level equal to the tank diameter. The tank is equipped with four equally spaced baffles whose width is one-tenth of the tank diameter. The tank is agitated with a 0.36-m-diameter, flat, six-blade disk turbine. The impeller rotational speed is 2.8 rev/s. The sparging air enters through an open-ended tube situated below the impeller, and its volumetric flow, Q, is 0.00416 m3/s at 25°C. Calculate the following the impeller power requirement, Pm gas holdup (the volume fraction of gas phase in the dispersion), H and Sauter mean diameter of the dispersed bubbles. The viscosity of the water, //, is 8.904 x 10 4 kg/(m-s), the density, p, is 997.08 kg/m3, and, therefore, the kinematic viscosity, v, is 8.93 x 10 7 m2/s. The interfacial tension for the air-water interface, a, is 0.07197 kg/s2. Assume that the air bubbles are in the range of 2-5 mm diameter. 

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