Safety Factors in AWWA Water Pipe Design: A Measurement against Risk?

There are many design factors that are involved that must be considered when designing a piping system. Historically, safety factors have been used as an indicator of safety versus failure. The design strength values have been established for materials, and then a factor or multiplier has been applied to assure that the material does not approach the design strength value established. But how safe are these values for the final design? This paper will look at the use of safety factors based on design criteria for AWWA standard water pipe. We discuss how the safety factor is established and how that applies to the actual design of the pipe. We will look at how the actual pipe material is supplied versus the value used for the design. The paper will also discuss the relevancy of how the safety factor affects the final design. The conclusion of the paper will explain how the safety factor is just a guide for the engineer to use in the evaluation of AWWA water pipe.