                         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                                                                                                                                                                                                                                          