In the engineering practice, it is often necessary to define supporting scheme and expansion loop requirements for piping distribution systems in very early phases of a project. While placing pipe supports is a relatively easy and straightforward task, providing accurate loop locations and dimensions for hot piping systems can often be challenging. In the early phases of any project it is impractical, costly and time-consuming to perform detailed stress analysis of a piping system in order to provide expansion loop dimensions, and therefore approximate methods are often used. Comprehensive overview of these existing procedures most commonly used in the engineering practice is given in the paper. However, fact is that most of the existing methods are based on the inconvenient charts and tables with scarce background data. Procedure proposed in this paper is based on over 150 expansion loop models and provides a simple and accurate analytical method to size and verify piping loops. Two fully worked examples show the simplicity and accuracy of the proposed model and its advantages over the methods typically used in the engineering practice.