Introduction to Piping Design

This course is about measurement of the flow rate of a fluid flowing under pressure in a closed conduit. This course is intended primarily for mechanical, civil and chemical, environmental, and industrial engineers. Someone completing this course will gain knowledge about twelve different types of meters for measuring fluid flow rate in a closed conduit. They will learn about typical calculations for differential pressure meters and pitot tubes. They will learn the general principles of operation for each type and general advantages and disadvantages of each.

It is common practice worldwide for piping designers to route piping by considering mainly space, process and flow constraints (such as pressure drop) and other requirements arising from constructability, operability and reparability. Unfortunately, pipe stress analysis requirements are often not sufficiently considered while routing and supporting piping systems, especially in providing adequate flexibility to absorb expansion/contraction of pipes due to thermal loads. So, when “as designed” piping systems are handed-off to pipe stress engineers for detailed analysis, they soon realize that the systems are “stiff” and suggest routing changes to make the systems more flexible. The piping designers, in turn, make changes to routing and send the revised layout to the pipe stress engineers to check for compliance again. Such “back and forth” design iterations between layout and stress departments continue until a suitable layout and support scheme is arrived at, resulting in significant increase in project execution time, which, in turn, increases project costs. This delay in project execution is further worsened in recent years by increased operating pressures and temperatures in order to increase plant output; increased operating pressures increase pipe wall thicknesses, which, in turn, increase piping stiffnesses further. Such increased operating temperatures applied on “stiffer” systems increase pipe thermal stresses and support loads. So, it is all the more important to make the piping layout flexible at the time of routing.

The report summarises the findings of pipe reviews which were conducted during the research project and highlights the following actions which should be considered during the hydraulic design of pipelines : • Review and incorporate available recorded hydraulic performance data of pipelines in the region in the design of new infrastructure; • Include the secondary energy loss associated with the dimensional details of the couplings in the calculation of the energy loss in the pipeline; • Use the proposed BRM (biofilm resistance model) to calculate a representative roughness for biofouled pipelines; • Implement the proposed procedure to determine the remaining useful life of pipelines to be able to prioritize the upgrading or replacement of system components; and • Provide monitoring points for the initial, continuous or intermittent hydraulic assessment of the pipeline.