D y E y = E y. Legend:

Transcription

1 MODAL APPENDIX 1 ASME BPVC.XII-2017 Figure 1-1.4(a)-2 Maximum Range for Tensile Strength Properties, for Categories 406, 407, and 412 Class 3 Tanks Where Yield Strength Is the Determining Criterion for Allowable Tensile or Compressive Stresses per TD D y E y = E y Legend: D y E y = (Design yield strength)/(section II, Part D tensile strength) = (Material Test Report yield strength)/(section II, Part D yield strength) GENERAL NOTES: (a) Determine E y, then detemine D y from this Figure. (b) Design yield strength = D y (Section II, Part D tensile strength). (c) 1.0 E y < 1.2: D y = E y ; 1.2 E y 1.33: D y = 1.20; 1.33 < E y 1.5: D y = 0.9E y. If E y > 1.5, then D y = 1.35 max. maximum principal stresses shall not exceed the allowables of TD-210 as determined by the equations for maximum principal stresses that are as follows: where s m a x = principal normal stress s s = shear stress in x and y planes s s m a x = principal shear stress s x = normal stress in x direction s y = normal stress in y direction In addition to the loading conditions listed above, there are emergency loading and energy absorption conditions that must be met by tanks of all categories. The load conditions to be considered are as follows: (1) Static Load Condition A: the stationary tank fully loaded with lading subject to MAWP and supported by running gear. The loading condition for multicompartment tanks and single compartment tanks shall be those that cause the maximum shell bending moments as well 204 as the maximum shear forces at supports. The weight of appurtenances attached to the tank shall be allowed for as well as the nonuniform weight distribution from a variable cross section tank such as a double conical tank. The weight of the running gear need not be included in the load applied to bend the tank. (2) Dynamic Load Condition B: the worst case loading condition of a fully loaded tank at MAWP subject to an incremental change in the vertical and longitudinal forces of ±35% of the tank weight ±20% of the tank weight in the transverse direction uniformly distributed. The longitudinal force shall be applied as a decelerative force (Condition B1) and as an accelerative force (Condition B2). The accelerative force will be applied at the fifth wheel, and the decelerative force will be applied entirely at the rear wheels (Condition B1a) and at the fifth wheel (Condition B1b). For truck mounted tanks, the longitudinal forces shall be applied at the mounts. (3) Dynamic Load Condition C: the worst case loading of a fully loaded tank, subject to a 70% vertical load increase (1.7 g total) in combination with MAWP, maximum allowable external working pressure, or atmospheric pressure (whichever results in highest stress at location considered). For Categories 406, 407, and 412 tanks, a vertical load increase of 42% (1.42 g total) may be used. Insert: [Note: For all load cases, evaluation shall include both internal MAWP and external MAWP (even if zero) conditions. Shell torsion and shear stresses shall be evaluated for transverse loads.]

2 ASME BPVC.XII-2017 MODAL APPENDIX 1 Replace Figure with attached Figure Figure Loading Conditions L L W L 1 L H R WA (a) Case A: Static Load Condition [Note (2)] R HA 0.2W T(DIST) 0.2R WB W 0.2R HB Plan View 0.2W T 0.35WT (B1) 0.35W H T (B2) K R HB 1.35 WW 0.35R HB (B1) 0.35R HB (B2) 0.2R WB R WB (B2) 0.35R WB (B1) R WB 1.35 R HB (b) Case B: 35% Vertical and Longitudinal Condition [Note (3)] R WC 1.7 (c) Case C: 70% Vertical Increase Condition [Note (4)] 1.7R HC 205

3 MODAL APPENDIX 1 ASME BPVC.XII-2017 Replace Figure with attached Figure. Figure Loading Conditions (Cont'd) 0.7W T (D1) 0.7W T (D2) 0.7 R HD (D1) 0.7 R HD (D2) 0.7 R WD (D2) 0.7 R WD (D1) R WD (d) Case D: 70% Longitudinal Load Condition [Note (5)] R HD 0.4W T(DIST) 0.4R WE W 0.4R HE Plan View 0.4W T(DIST) 0.4R HE 0.4R WE W R WE W R HE (e) Case E: 40% Lateral Load Condition [Note (6)] 2W T R WF (f) Case F: 200% Longitudinal Load Condition [Note (7)] R HF NOTES: (1) Load distributed over tank length. (2) W = W T + + ; loaded with internal pressure. (3) Vertical increase of 35% and 20%; transverse load computed in both acceleration (B1) and deceleration (B2); loaded with internal pressure. (4) 1.7W = 1.7 (W T + + ) (5) Compute as both acceleration (D1) and deceleration (D2). (6) Compute as both shear and torsion stresses. (7) Pressure on front head is augmented by 2W less 0.25W per baffle up to four baffles, leaving minimum augmentation of W; design stress = 0.75(UTS). 206

4 Editorial Note: this is a completely revised Fig All variables used in the figure are defined in the Definitions following the sketches.

5 Editorial note per previous voting comments: All relevant notes from current figure are either explained in the revised definitions or in the text.