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 ).
||3 July 2010
|PDF File Size:
|ePub File Size:
||Free* [*Free Regsitration Required]
COADE Pipe Stress Analysis Seminar Notes
I will Probably get flamed for this, but here goes. Expansion joints also present problems due to the fact that they cannot transmit tension through their wall.
Consider the following geometry, of a large diameter pipe supported hy a dual spring assemhly: Sustained loads are classified as those caused by mechanical forces which are present throughout the normal operation of the piping system.
Or more simply, the “theoretical” cold load is the cold load to be specified in the factory order of the spring, while the “actual” cold load is an approximation ofthe reading ofthe spring load after pulling the swminar upon initial installation.
Bending and lateral convolution spring rates can be computed from the axial spring rate. The stress equations were quite similar throughout the piping codes i. Note that primary loads srminar usually classified further, according to their duration ofloading. Page of Coade seminar notes suggests App D sifs Ii,Io be included in the calculation of the sustained loads Sl, and that the occasional loads be calculated likewise.
Included in this section is information on the following subjects: A subsequent analysis showed that ntoes temperature increase in the adjacent vessel and piping system alongwith a relocation of pipe restraints for the noets operating conditions made several years ago caused the stresses to exceed the expansion allowables. Sustained and Occasional loads are both “primary” and can lead to collapse.
The number and location of supports should be determined by the location and strength of building steel. Design data typically required in order to do pipe stress analysis consists of pipe materials and sizes; operating parameters, such as temperature, pressure, and fluid contents; code stress allowables; and loading parameters, such as insulation weight, external equipment movements, and wind and earthquake criteria. For Short Radius Bend R 1 – cosa The properties ofthat bellows are then inserted into the piping model.
Ifthis is not the case, the loads can he estimated by a thorough thermodynamic analysis. This points to an important rule of design – if supports are placed as near as possible to concentrated loads, the effect ofthese loads from a stress point ofview may be neglected. CAESAR II flags these with a warning during the analysis and reports them as zero load constant effort supports in the hanger table during output.
In this case it is necessary to ignore the “actual” cold load, and in some cases it may be preferable to adjust the springs in the field to carry the cold load once the system has been filled.
Therefore, what you do with one, you must do with the other. Rodabaugh does however suggest that the normal usage whereby the width of noes pad is taken to be at least equal to the radius ofthe nozzle should be observed even though not explicitly directed by the code.
Not one, but two different criteria must be satisfied, one for primary loads, which may lead to single application catastrophic failure, and one for cyclic, dis placementdriven loads that may lead to fatigue failure especially in the vicinity offittings and other discontinuities after repeated applications. Due to the low allowable stress value used, there is sufficient factor of safety that this standard span may notse applied to a wide range of piping configurations.
Note that constant effort spring supports have no dynamic effect on a piping system. Valve opening time and duration of the jet load affect the dynamic response of the system, thus affecting the developed loads. Figure For the most part, these details are taken care ofby the expansion joint manufacturer. The static loading magnitude is considered to be in direct proportion to the element’s weight.
The first concern is to locate them near concentrated loads – supports should he located as close as possible to the two valves for example, near node points 20 and How many directions should be analyzed for sensitivity to wind?
In many design problems the joint is used to protect a sensitive piece of equipment from excessive nozzle loads. Additionally, support manufacturers typically limit the range of a hanger rod’s arc in to values such as 60, where the arc can be calculated as: It is often highly conservative to apply nites the calculated force as a static load, but this is still often foade.
Not only are the causes and the failure modes ofthese two loading types quite different, but not surprisingly, the solutions to these two types ofloading are usually different as weIl.
As the tlI’ ratio gets much smaller than one, the largest stresses shift to the branch. Such pressure design requirements are encompassed in the minimum wall thickness requirements discussed in detail notse separate sections of the codes. Unless the user is willing to put a spring at the stanchion location, the differential thermal growth in this small area might result in large nozzle loads.
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.
COADE Pipe Stress Analysis Seminar Notes – Free Download PDF
Cold spring should be omitted from the restrained weight case, and included in the operating load case for hanger travel. Rather catastrophic failure can occur seminr some usually high number of applications of the load. When using restraints to absorb the unbalanced pressure load, it is recommended that guides be located on the adjacent pipe runs in order to reduce the danger ofbuckling.