Session: DA-02-02 Design & Analysis of Piping and Components - 2

Paper Number: 102680

102680 - HDPE Piping Stress Analysis Using the Caesar Software With New NM.1 and NM.3.3 Codes. 

This technical paper defines a consistent approach for the stress analysis of PE piping based on guidelines of ASME NM.1.  It includes CAESAR II setup (as an example) for PE stress analysis and determines the qualification criteria for PE piping stress analysis.

Recently ASME published NM.1 for thermoplastic piping systems, however this standard(code) does not exist in the Caesar software (most recognized industrial software for stress analysis) . 

The user of this document could run the stress analysis of HDPE through Caesar software.

 Right now, most of the stress engineers do not have proper tools or software for doing the stress analysis of HDPE to calculate the force or moments on each point. Assume the HDPE pipe connected to any Tank or vessel and you need to analyze/calculate that the nozzle could take the loads from piping side or not! You need to calculate the piping loads (include sustain and expansion) and compare to the nozzle allowable loads! Then required to quantify the loads for comparing that. This paper provides you the guideline to calculated the forces and moments with using the NM (NM.1 -NM3.3) codes and industrial software application. 

 Guideline to how incorporate the correct allowable stress and implementing on the software. Implementing the service temperature and environmental factor. The other critical factor, Apparent elastic modulus to meet the code cycles as well as   how it will be implemented regarding the duration of sustained loading to have safe and standard design. 

Guide line to show how we are incorporating   the poison ratio and thermal coefficient factor. Other important subject will be defining the load cases as required. As we are using the B31.1 regarding to have similar piping stress formula compare to NM) material then the sustain loads required to be allocated for operation cases. In tis situation the software will check all the load cases . This method will be implemented on the occasional loads as well. This is trick that required to use for checking all the load cases.

I defined the SIF (stress intensification factor ) for all the fitting as well . This table also is available in the new code . Also finding some ways to reduce impaction of buckling on the analysis to have conservatice result. 

In conclusion, with having this  paper you have all the information and guideline step by step to  show the reader how to calculate and doing the HDPE stress analysis and filling out this deficiency in the non metallic industry .

Also this paper prove that how the new NM code will be implemented on the industrial application/technology and will be extended in future in any new finite element analysis  piping software.

Presenting Author: Mehdi Fathi Bantrel (Bechtel affiliate Canada)

Presenting Author Biography: I am professional engineer of Ontario and Saskatchewan, PMP certificate, having 20 years of experience on piping stress engineering in the petrochemical, mining, power, and oil fields.
Having the Master of mechanical engineering from Sharif University and started to participate on the ASME Pressure vessel and piping in Toronto (2012).
Past 7 years focus on piping stress analysis of plastic piping specially HDPE and FRP. Recently ASME published ASME NM.1 and NM.2 ALSO NM3.1, NM3.2 AND NM3.3.
I prepared that this paper using PPI handbook but now I formalized it with ASME code. I believe this technical paper is very useful for industrial engineering now as I saw that deficiency there.

Authors: