Introduction

In response to the increasing number of fatal accidents in the early part of the 20th century specifically as a result of the rapid development of steam-driven engines and the total lack of legally accepted standard practice, the demand for codes and standards providing a systematic approach to pressure technology was introduced.

Within the framework of these codes, it is clear that the primary reason for performing Pipe Stress analysis is to ensure the safety of process plant operating personnel and the general public. In support of this primary reason, it is therefore imperative the design of plant and equipment is evaluated in terms of the structural and operational considerations of process piping systems with particular reference to the analysis of the associated mechanical contributions considered via pipe stress analysis.

In providing for a safe working environment achieved through the optimal design of piping systems, the validity of stress analysis requirements may be substantiated with consideration as to whether the following parameters are a precursor to plant safety;

• To ensure the level of stress within piping systems complies with Code limitations
• To validate sufficient flexibility exists within piping configurations that maintains nozzle loads on equipment within the allowable limits of recognised
• To check that the level of stress on vessel nozzle connections are within vessel code
• To calculate loads at supports for incorporation into safe structural
• To review the possibility of leakage at joints
• To provide a check on the extent of piping displacement related to interference with other
• To investigate the effects of dynamic parameters such as mechanical and acoustic vibration, transient flow, compressor pulsation due to wave propagation, wave induced fatigue slug flow and relief valve reaction
• To qualify piping systems subject to elevated temperatures or pressure (external or internal) or systems with critical or hazardous service

Any combination of these considerations would not only direct iterative design more efficiently but also present sufficient justification to investigate a piping system by performing a stress analysis of commensurate degree of complexity and in turn provide both Code validation and design optimisation as an intended outcome.

CAESAR II software is the preferred computer program referenced and utilised on this course. Amongst numerous others on the market it has been developed to provide a structural analysis for piping systems using three-dimensional beam elements and while it is not as accurate as finite element solutions, the ease and efficiency of using this method provides sufficient accuracy in conservatively addressing Code requirements. It is important to note however that any stress analysis program is merely a tool and that only with a firm foundation of understanding of the fundamentals of stress can the processing of results be likely to engender realistic and practical value.

Objectives

The objective of this course is to present the student with methodology in clearly and systematically building a foundation of understanding of the requirements for performing Pipe Stress Analysis.

The course is developed sequentially. First, a rigorous review of basic stress concepts typically encountered in undergraduate solid mechanics courses is undertaken. These concepts are then developed with specific reference to CODE compliance parameters so that the student becomes comfortable with the selection and use of various methods available in different codes for evaluating flexibility.

Next, the student is introduced to some fundamental material parameters and selection criteria along with various and typical piping components and their use. This review is followed by a study of restraint mechanisms and how their different functions are related to developing necessary control of deflections and loadings. This sequence of presenting the course objectives provides the groundwork in presenting the student with a working appreciation for the fundamental input parameters necessary to begin building and competently analysing pipe stress models.

Limited places.

The training covers online-based study through the following modules:

Module 1: Review of Basic Stress Principles

• Solid Mechanics Basics
• Mohr’s Circle for 2D Stress
• Failure Theories – Rankine, Tresca, Huber-Henkey-Von Mises
• Stress Intensification Factors
• Stress classification
  • Axial
  • Shear
  • Bending
  • Longitudinal Pressure
  • Torsion
  • Hoop
  • Fatigue
  • Displacement
• Module 1 Quiz

Module 2: Code Requirements for Flexibility Analysis

• Introduction
• Reference Standards and Codes
• Code Stress Cases
  • Sustained (Deadweight)
  • Displacement
  • Hydrostatic & Pneumatic
  • Fatigue
  • Wind
  • Creep
  • Dynamic
• Code Stress Load Combinations
• Simplified Analysis Methods
• CAESAR II data input
• Module 2 Quiz

Module 3: Piping Components & Material Properties

• Material Selection
  • Selection Criteria
  • Material Strength & Stress Basis
• Piping Components
  • Pipe Size (NPS)
  • Fittings (Elbows)
  • Branch Connections (Reinforced & Unreinforced Tees)
  • Flanges, Bolting and Gaskets
  • Welded Attachments
• Module 3 Quiz

Module 4: Restraints & Supports

• Restraint Functions (Forces & Moments)
• Restraint Types – Nozzles & Anchors
• Support Types – Static & Dynamic
• Span criteria based on Deadweight, Sag and Natural Frequency
• Support loads
• CAESAR II Support Symbols
• Module 4 Quiz

Module 5: Modelling a Piping System

• Data Gathering and analysis sequence
• Piping Selection Criteria
• Pipe
• Equipment
• Nozzles
• Flanges, Valves & Rigid Components
• Supports
• Module 5 Assignment

Module 6: Static Stress Analysis

• Documentation
• Data input parameters (isometric, cut-off, load cases, restraints )
• Data Analysis
• Pipe Stress Design Guide
• Module 5 Assignment Review

Alexander Teesdale MSc. – Piping & Stress Engineering Consultant

Alex is a Consulting Engineer with over thirty years of experience in the design and development of greenfield and brownfield Oil and Gas projects both onshore and offshore. He specializes in the disciplines of 3D Piping Layout, Valves, Vessels and Pipe Stress Engineering and is experienced with project phases ranging from front-end engineering design (FEED) through detailed design to procurement, installation and construction.

His main roles have been to ensure the required level of Quality and Technical Safety has successfully been obtained to ensure Code compliance detailed in relevant project contractual schedules and budget limitations so as to optimise costs through systematic and rational review of Project Specifications and Procedures, General Specifications, discipline requirements and international norms, standards and specifications.

Alex has worked in both Project Owner and Contractor positions overseeing detailed design and validation of related documentation so as to provide coordination and advancement of safe and practical engineering design, related procurement, efficient installation and constructability (EPIC).

The course is delivered online through our easy-to-use Virtual Campus platform. For this course, a variety of content is provided including:

– eLearning materials
– Videos
– Interactive multimedia content
– Live webinar classes
– Texts and technical articles
– Case studies
– Assignments and evaluation exercises

Students can download the materials and work through the course at their own pace.
We regularly update this course to ensure the latest news and state-of-the-art developments are covered, and your knowledge of the subject is current.

Live webinars form part of our course delivery. These allow students and tutors to go through the course materials, exchange ideas and knowledge, and solve problems together in a virtual classroom setting. Students can also make use of the platform’s forum, a meeting point to interact with tutors and other students.

The tutoring system is managed by email. Students can email the tutor with any questions about the course and the tutor will be happy to help.

This course is presented to engineering students, graduates and piping designers who are interested in obtaining a fundamental appreciation of the stress concepts directly applicable to pipe stress analysis and related Code compliance. This course may also provide a robust refresher course for industry professionals in both engineering and management wishing to brush up on the fundamentals of this intrinsic safety subject.

It is well known that there is no substitute for experience. Good experience is built on accumulated and practical education gained by the application of sound principles and understanding. This course therefore comprises a comprehensive primer for any individual wishing to enter the discipline of pipe stress analysis

Even with standardised piping layout practices and routine methods of piping design, it is highly unlikely that the piping geometry between systems within any two projects will ever be duplicated. This provides a vast scope for practitioners involved in the evaluation of critical piping systems on projects worldwide.