Pipe Sizing, Pipe Wall Stresses and Water Hammer (Virtual Classroom)

Pipelines move fluids by pumps under steady state conditions. However, when the flow becomes unsteady – for example, when a downstream valve in a pipeline is closed rapidly – the result can be catastrophic. Changes in the flow direction can create pressure surges producing stress in the pipe wall and a loud banging noise called, water hammer.

It is important to understand the relationship between the pipe wall stresses and the changes in fluid pressure and velocity to predict a pipe wall failure. This course furnishes students with the equations and calculations necessary to solve these problems. It also provides a review of fluid mechanics: fluid properties, equations for steady and for unsteady flows, flow in a pipeline, friction factor, hydraulic and energy gradient lines, and axial and hoop stress calculations in a pipe wall. Once this background is provided, the unsteady flows can be modeled without undue difficulty. 

Today, the solutions may be obtained rather quickly using a spreadsheet. Spreadsheet results allow the user to define how quickly a valve is closed, for example, and obtain results immediately. The user may change pipe diameter, friction factor, pipe length, etc., and immediately determine the effects on pressure and on flow rate. Other unsteady flows can also be described by the same equation. In fact, the water hammer problem can be extended to model the unsteady flow of other fluids. (Oils, for example, are especially important.)

The course includes exercises to provide participants the opportunity to solve unsteady flow problems with spreadsheets using the proper equations and calculations.

Special Requirements

Attendees should bring a calculator

Course Materials

Learners are furnished with downloadable spreadsheets and a PDF version of the course presentation.

You Will Learn To

• Model steady flow fundamentals in a pipeline
• Describe and model the unsteady flow called water hammer
• Explain how water hammer results in excessive pipe wall stresses
• Predict when such stresses exceed the yield stress of the pipe material
• Avoid pipeline design and operating conditions that may lead to water hammer

Who Should Attend

The class is designed for practicing engineers in the power and process piping areas, including those in power companies, utility companies, valve and pipe manufacturers, oil industries. 

This ASME Virtual Classroom course is held live with an instructor on our online learning platform. Certificate of completion will be issued to registrants who successfully attend and complete the course.