METHODOLOGY VESSEL DESIGN The vessel volume and surface calculations are performed using four types of heads. You may select Flat Heads, ASME F&D,2-1 elliptical,or HemiSpherical Heads. The flexibility to use different heads for the top and bottom was not included. Designs with Hemi heads should be used with caution, since it is unusual for them to be selected except for very high pressure designs. Special design techniques are often used for very high pressure applications that go beyond the capabilites of this program. Cylinder Volumes The volume of the vessel cylinder between the seam to seam dimensions is base upon the internal diameter in inches specified and the height given. The formula for the volume is : V = 3.1416/4 * (D/12)^2 * H/12 ft^3 The surface of the Cylinder is calculated by the formula A = 3.14.6*D/12*H/12 ft^2 The thickness of the cylinder is calculated by the ASME formulas If P > 0.385 * S * E then the thick wall equation is used T = R * ((S*E + P ) / (S*E - P))^0.5 - 1 + CA ELSE The thin wall equation is used {this is the usual case} T = (P*R / (S*E - 0.6*P) + CA IF the calculated thickness is less then 0.25 inches then a default thickness of 0.25 inches is used. The weight of the cylinder is calculated by W = A * T * METAL WEIGHT with units corrected The metal density used is 0.283 lb/ in^3 for steel It can be changed as well as the values used for S, and E and CA in the screen called up by pressing W from the command line. HEAD DATA The data for the various heads is calculated as follows for the head volume, surface areas, shell thickness and weight. FLAT HEADS ( no design pressure calculation is made ) A = Pi/4*(D/12)^2 V = 0 DEPTH = 0 T = 0.25 in ASME F&D A = Pi*(D/24)^2 * ( 1 + X^2*(2 - X) Where X = 0.3334 V = 2*0.1667*0.667*Pi*(D/24)^3*7.47 DEPTH = X * D/2 T = T by thin wall eq * 10.6 / 6 + CA 2-1 Elliptical A = (Pi * (D/24)^2)*(1 + X^2*(2-X) Where X = 0.5 V = 0.0005667*(D)^3 DEPTH = X * D/2 T = P*D / (2*(S*E - 0.1*P)) +CA HEMISPHERICAL A = 1.5708*(D/12)^2 V = 0.0011335 * (D^3) DEPTH = D/2 T = (P*D/2) / (2*(S*E - 0.1*P)) +CA UNITS A = AREA FT^2 V = VOLUME IN GALLONS DEPTH = INCH D = INTERNAL DIAMETER INCH T = THICKNESS INCH CA = CORROSION ALLOWANCE INCH P = DESIGN PRESSURE PSI E = WELD EFFICIENCY 0.75 TO 1 R = RADIUS INCH S = ALLOWABLE STRESS LIQUID HEIGHT The height of the liquid in the vessel is calcuated from the bottom tangent or seam dimension. It is calculated from the volume of the liquid inputted in the Liquid input section by subtracting the volume of the bottom head and determining the straight side volume of liquid. The baffle width is calculated by BW = D/12 The baffle offset from the wall is calculated by BO = D/72 STRESS VALUES TO USE Stress values vary with the type of metallurgy typical values are as follows: Metal Allowable Stress (psi) SA515-55, SA516-55, SA285C 13700 SA515-60, SA516-60, SA-53B 15000 SA515-65, SA516-65 16200 SA515-70, SA516-70 17500 SA240, 304LSS, 316LSS 17500 SA240, 304SS, 316SS 18750 SA240, 321SS, 347SS 18750 SA240, 410SS 16250 MONEL 400 21000-30000 INCOLOY 600 26000-37000 TITANIUM 8700-16300 SA285C 20% 304 OR 316 CLAD 14700 HASTELLOY G 25100 CARPENTER 20 20000 ZIRCONIUM SB551 13050 TANTALUM 11250 ALUMINUM 5456 10200-11500 NICKEL SB-162 10000-13300 NICKEL SB-127 17500-18700 NICKEL SB-168 20000-21200 WELD EFFICIENCY VALUES The value of weld efficiency to use in the thickness calculation are determined by the weld procedures as follows: TYPE OF JOINT FULL X RAY SPOT X RAY VISUAL double butt weld 1.0 0.85 0.70 single butt weld 0.90 0.80 0.65 with backing strip single butt weld W/O backing strip --- --- 0.60 double full fillet lap joint --- --- 0.55 single full fillet lj with plug welds --- --- 0.50 single lap without plug welds --- --- 0.45 METAL DENSITY METAL DENSITY LB/IN^3 CARBON STEEL 0.283 304 SS 0.301 316 SS 0.301 MONEL 400 0.324 ALUMINUM 0.0994 INCONEL 600 0.326 NICKEL 0.326 TITANIUM 0.1669 ZIRCONIUM 0.240 HASTELLOY G 0.3056 HASTELLOY C 0.327 HASTELLOY B 0.339 CARPENTER 20 0.330 TANTALUM 0.6079