The Diameter field is used to specify the pipe diameter. Normally, the nominal diameter is entered, and CAESAR II converts it to the actual outer diameter necessary for the analysis. There are two ways to prevent this conversion: use a modified UNITS file with the Nominal Pipe Schedules turned off, or enter diameters whose values are off slightly from a nominal size (in English units the tolerance on diameter is 0.04 in.). Use <F1> to obtain additional information and the current units for this input field. Available nominal diameters are determined by the active pipe size specification, set via the configuration program.
The following are the available nominal diameters.
ANSI Nominal Pipe ODs, in inches (file ap.bin)
½ ¾ 1 1 ½ 2 2 ½ 3 3 ½ 4 5 6 8
10 12 14 16 18 20 22 24 26 28 30 32
34 36 42
JIS Nominal Pipe ODs, in millimeters (file jp.bin)
15 20 25 32 40 50 65 80 90 100 125 150
200 250 300 350 400 450 500 550 600 650
DIN Nominal Pipe ODs, in millimeters (file dp.bin)
15 20 25 32 40 50 65 80 100 125 150 200 250 300 350 400 500 600 700 800 900 1000 1200 1400 1600 1800 2000 2200
Wt/Sch
The Wall Thickness/Schedule field is used to specify the thickness of the pipe. Normal input consists of a schedule indicator (such as S, XS, or 40), which will be converted to the proper wall thickness by
CAESAR II. If actual thickness is entered, CAESAR II will accept it as entered. Available schedule indicators are determined by the active piping specification, set via the configuration program. The available
schedules are listed below.
ANSI B36.10 Steel Nominal Wall Thickness Designation:
S - Standard XS - Extra Strong
XXS - Double Extra Strong
ANSI B36.10 Steel Pipe Numbers:
10 20 30 40 60 80 100 120 140 160
ANSI B36.19 Stainless Steel Schedules:
5S 10S 40S 80S
JIS PIPE SCHEDULES 1990 Steel Schedules:
10 20 30 40 60 80 100 120 140 160
1990 Stainless Steel Schedules:
5S 10S 40S
DIN PIPE SCHEDULES none
Note: Only the s (standard) schedule applies to wall thickness calculations for DIN.
+Mill Tol %
The Positive Mill Tolerance is is only enabled when IGE/TD/12 is active, and is used when the Base Stress/Flexibility On directive of the Special Execution Options is set to Plus Mill Tolerance. In that case, piping stiffness and section modulus is based on the nominal wall thickness, increased by this percentage. The user may change this value on an element by element basis.
-Mill Tol %
The Negative Mill Tolerance is read in from the configuration file for use in minimum wall thickness calculations. Also, for IGE/TD/12, this value is used when the Base Stress/Flexibility On directive of the Special Execution Options is set to Plus Mill Tolerance. In that case, piping stiffness and section modulus is based on the nominal wall thickness, decreased by this percentage. The user may change this value on an element by element basis.
Seam-Welded
This directive is only activated when the IGE/TD/12 code is active. This is used to indicate when straight pipes are seam welded and affects the Stress Intensification Factor calculations for that pipe section due to Seam Welded fabrication.
Corrosion
Enter the corrosion allowance to be used order to calculate a reduced section modulus. A “setup file”
directive is available to consider all stress cases as corroded.
Insul Thk
Enter the thickness of the insulation to be applied to the piping. Insulation applied to the outside of the pipe will be included in the dead weight of the system, and in the projected pipe area used for wind load computations. If a negative value is entered for the insulation thickness, the program will model refractory lined pipe. The thickness will be assumed to be the thickness of the refractory, inside the pipe.
Temperatures
There are nine temperature fields, to allow up to nine different operating cases. Temperature values are checked (by the error checker) to insure they are within the code allowed ranges. Users can exceed the code ranges by entering the expansion coefficient in the temperature field in units of length/length. The expansion coefficient can be a useful method of modeling cold spring effects. Also when material 21(user-defined material) enter temperature *expansion coefficient as in the example below.
Values entered in the temperature field whose absolute values are less than the Alpha Tolerance are taken to be thermal expansion coefficients, where the Alpha Tolerance is a configuration file parameter and is taken to be 0.05 by default. For example; if the user wanted to enter the thermal expansion coefficient equivalent to 11.37in./100ft., the calculation would be:
11.37in./100ft. * 1 ft./ 12in. = .009475 in./in.
This would be entered into the appropriate Temperature field.
Note: A cut short is no more than reducing a pipe element's length to zero (for example; if we wanted 8.5 cm of cold spring we could put in an 8.5 cm long element and then thermally shrink its length to zero).
This allows the cold spring to be manipulated as an individual thermal case rather than as a concentrated force.
Access to operating conditions 4 through 9 is granted through the Extended Operating Conditions input screen, accessible via the Ellipses Dots button directly to the right of the standard Temperature and Pressure input fields. This dialog box may be kept open or closed for the convenience of the user.
Pressures
There are ten pressure fields, to allow up to nine operating, and one hydrotest, pressure cases. When multiple pressures are entered, the user should be particularly careful with the set up of the analysis load cases, and should inspect CAESAR II's recommendations carefully before proceeding.
Access to operating pressures 3 through 9 is granted through the Extended Operating Conditions input screen, accessible via the Ellipses Dots button directly to the right of the standard Temperature and Pressure input fields. This dialog box may be retained open or closed at the convenience of the user.
Entering a value in the HydroPress field signals CAESAR II to recommend a Hydrotest load case.
Enter the design gage pressure (i.e. the difference between the |internal and external pressures).
Note: CAESAR II addresses negative pressures as follows:
- the absolute value of the longitudinal pressure stress (PD/4t) term will be added to the appropriate code equations
- pressure thrust forces applied to expansion joint ends will be compressive.
- buckling is not addressed in CAESAR II.
Note: The BOURDON (pressure elongation) EFFECT is "OFF" by default. (It is assumed to be non-conservative.) Users wishing to activate the BOURDON EFFECT may do so via the Special Execution Options.
The BOURDON EFFECT is ALWAYS considered in the analysis of Fiberglass Reinforced Plastic pipe, Material id=20.