COADE Pipe Stress Analysis Seminar Notes – Ebook download as PDF File .pdf) , Text File .txt) or read book online. Download COADE Pipe Stress Analysis Seminar Notes. Scribd is the world’s largest social reading and publishing friends, i have a very old edition of “coade pipe stress analysis-seminar notes” (i think ).
|Published (Last):||26 June 2012|
|PDF File Size:||7.59 Mb|
|ePub File Size:||4.53 Mb|
|Price:||Free* [*Free Regsitration Required]|
COADE Pipe Stress Analysis Seminar Notes
Typical sustained loads consist of: Cold load design balances the weight loads in the cold, rather than the hot, condition. These limits nnotes presented in different ways in different manufacturer’ s catalogs, but are always functions of the number of notrs cycles, bellows material properties and convolution shape.
Several examples should help illustrate: After 12 years of successful operation, inspection of the inside surface of a vessel revealed fatigue cracks in the vicinity of a piping nozzle connection.
Dave DiehlRichard Ay.
In these cases, the user may instruct the design algorithm to bypass consideration of short range springs and start with mid-range springs frrst unless space limitations require it. The simplest method of estimating pipe stresses due to weight is to first consider the pipe as being a continuous run, with supports located at constant intervals this is a somewhat accurate model ofpiping traveling horizontally, mounted srminar racks, and with a minimum ofin-line components: These elements are defined by two node points one at the “from” end, and the other at the “to” endeach with fixed spatial coordinates and six degrees of freedom three translational and three rotational.
In these sekinar the user can force a hot load higher or loweroverriding the program calculated value in an attempt to tune weight distribution and bring the equipment loads within the allowables. Expansion joints may vary in terms of the number and type of convolutions, the material, the number of plies, all ofwhich effect the pressure capacity, the stiffness, and the seminaf movement. In order to save even the brief time required to calculate LaU, the Manufacturer Standardization Society of the Valve and Fitting Industry has calculated allowable piping spans for various piping configurations, and published them in their standard MSS SP Figure Response of the elements under load is governed according to recognized strength of material COADE Pipe Stress Ciade Seminar Notes relationships as described in Section 6 ofthese notesswminar to certain limiting assumptions.
They have calculated the maximum allowable piping weight spans based upon the following coaed Although the course is taught using the CAESAR II Pipe Stress Analysis Software, the skills learned here are directly applicable to any means of pipe stress analysis, whether the engineer uses a competing software program or coadee manual calculational methods. When using those codes which define a stress intensification factor for reducers, one would have to he calculated and specifically applied at that location.
The next concern is the placement of supports on the riser. A few of these foIlow: Rigid element modeling tlange. The rigidity, weight, and moment due to the offset is best modeled using a weightless rigid element going from the centerline of the pipe out to the center of gravity of the process monitor, at which point a small rigid element with the weight ofthe equipment should be modeled.
Bearn theory states that ifboth support points are pinned free to rotate: The coadf are further defmed by a constant non-varying along the element length set of stiffness parameters i. If the engineer supports a piping system such that no span in the system exceeds the standard spans listed in the table, it is virtually certain that the system is adequately supported for weight loading.
The Expansion Joint Manufacturers Association recommends that the first guide be placed a distance no further than 4 pipe diameters from the expansion joint, with the second guide placed no further than 14 pipe diameters from the first. Rigid coadf whose cumulative weights equal that ot the torged titting and tlanges. Figure The following sections of these seminar notes provide more detailed methods for modeling and analyzing specifie components of the piping model.
The stress isometric Figure is a sketch, drawn in an isometric coordinate system, which gives the viewer a rough 3-D idea of the piping system. Ifthe plant site is greater than miles from either the east or the gulfcoasts, then a value of miles should be used no coqde may he taken for any plant site greater than miles from any ofthese hurricane coaed areas.
Coave is codified in the requirement that expansion analysis need not be explicitly done for a system meeting the following conditions: Note that in the event that the opening time is not known, a conservative value of 2. Even though the calculated coare range at the COADE Pipe Stress Analysis Seminar Notes junction was weil overpsi, thejunction survived several years hecause of the selfrelieving nature of the thermalload, and the fact that the system cycled fewer than a dozen times over the two year period.
Earthquake static load cases are set up and determined exactly as they are for wind occasional loads, i. As noted, seminra elements are modeled as stick elements ofconstant cross-section and material properties. Other items such as imposed displacements, concentrated loads, etc. This can be accounted for by increasing the flexibility ofthe elbow element in the computer model and multiplying the calculated stress by a stress intensification factor this is done automatically by most programs such as CAESAR II.
Additionally, the subtraction of Sl-S3 does not produce a simple expression for the stress intensity. It should be noted that the piping codes exactly calculate the stress intensity twice the maximum shear stress only for the expansion stress, since this load case contains no hoop or radial components, and thus eeminar an easy calculation. Examples ofthese documents are shown in Figures through on subsequent pages. The default interpretation ofthis requirement is to calculate the sustained and seimnar stresses independently as per the equation given for sustained stresses above and then to add them absolutely.
Note however that the bending flexibility coefficient should not he used in any piping notds. However, the effects of the rigid elements on the piping system can he simulated by providing an element ofhigh relative stiffness in the model it is always more important to adequately model relative stiffnesses than absolute stiffnesses when constructing a model. Elbows ovalize significantly when subjected to bending loads.
COADE Pipe Stress Analysis Seminar Notes – Free Download PDF
Note that torsional stiffnesses are not usually provided, since unprotected expansion joints are not designed to carry torsionalloads and may fail catastrophically if inadvertently exposed to even moderate torsional moments. This is also in reality, a difficult problem to design for. Thank you for interesting in our services.
This section describes the assumptions used in the computer algorithms in order that the user may more fully understand the limitations and the potential work-arounds of the system. In Figurethe system consists of a 12″ diameter, standard schedule steel pipe filled wi th water, wi th a design pressure of psi, and a design tem perature of F, which runs hetween notew equipment nozzles.
In this case it is necessary to ignore the “actual” cold load, and in some cases it may semjnar preferable to adjust the springs in the field to carry the cold load once the system has been filled.
The manufacturer must always provide a fatigue curve or sorne other type of adjustment factor in order to determine the allowable displacementforadifferentnumberofcycles.