# Flowsheet Snap, Scale and Grid

The flowsheet can be operated in any one of three modes: 1.Free format. 2.With an ortho snap. 3.With an iso snap. Coupled with these options the user has control of the scale of the flowsheet (zoom) and the grid characteristic. The snap and scale settings are saved with each flowsheet so that you can work in different modes in different flowsheets. It is possible to change modes at any time, although this is not recommended if you wish to retain a consistent layout of elements. Each mode is selected by toggling either of the two buttons on the flowsheet toolbar shown below... If the button is highlighted, then the corresponding mode is selected, if neither button is highlighted then free format is selected. Scale and grid settings and visibility are made from the two drop-down options on the upper toolbar: The left drop-down provides the scale of the flowsheet; the right drop down allows you to show no grid, a fine grid or a coarse grid. (In Free Format mode this setting is ignored). Free Format This means there is no snap and elements can be placed anywhere. You can even overlap components if you wish, although this is not recommended as the flowsheet can quickly become unreadable. A network constructed in free format is shown below. Ortho Snap In this mode the snap grid is represented by a square mesh and the center of each element snaps to a predefined position. You can show the snap grid if you find this a useful concept. The distance between the snap positions and the default size of each component is controlled via the scale and grid settings. The screen display shown below shows an orthogonal layout with a coarse grid. Notice that each node element can only be positioned at a discrete point on the grid and that irrespective of the node size it is the center of the node that snaps to the grid point. Snapping to the center of each node means that pipes appear horizontally or vertically provided the nodes are horizontally or vertically aligned irrespective of node element size, which can be a useful asset in making tidy layouts. Iso Mode In this mode the center of each node snaps to a predefined position on an isometric grid (i.e., 30° and 90° lines only). Similar to the ortho mode the scale and grid visibility controls also apply. How does the Ferris Wheel look as an isometric view ?, see below. As you can see this mode aids tidy drawing of horizontal and vertical layouts (horizontal lines are now at 30°). The odd man out above does not lie on a horizontal or vertical plane with the connector but at a slope. Node that the ortho and snap modes are not meant to represent accurate engineering drawings that you would expect to find in a CAD package. Instead they are simply layout aids to help you represent the network layout in a familiar format. You should also note that text never follows any snap rules. Text can always be placed at any position.