# Showing node and pipe numbers

Each element on the flowsheet has a unique number assigned by FluidFlow. You cannot change the number that FluidFlow assigns, however you can use the Unique Name field that is common to all components to enter your own numbers or descriptions. The numbering convention used by FluidFlow is that nodes are numbered from 1 upwards and pipes are numbered from -1 downwards. This means nodes always have positive numbers and pipes always have negative numbers. Other flowsheet elements such as text do not have numbers. To decide if you wish to show the numbers assigned by FluidFlow on the flowsheet, toggle to the on or off position the following buttons (icons are shown below) which can be found on the flowsheet toolbar.