The Simple Flow Pipe panel is shown for classical flow pipes (as opposed to the segmented flow pipes).
The following properties are on the Simple Flow Pipe panel:
The content that the pipe will hold at any time (the pipe can never be below its maximum content). This value is used, together with the outflow rate, to determine the time for products to travel from one end of the to the other.
Calculate Max. Content From Size
Automatically calculate the maximum content based on the pipe geometry. This calculates πr2L, where L is the height of the pipe (its x-size) and r its radius (the y-size). The z-size of the pipe is ignored.
Show arrow along flow direction
At this point the pipe is unidirectional: you cannot reverse the flow. This may change in a later release. The "Show arrow" checkbox labeled "Flow direction" will draw an arrow next to the pipe indicating the direction of flow of material in the pipe, even if the actual flow rate is zero. The color of the arrow will correspond to the product type currently leaving (or, when there is no flow, sitting at the output end) of the pipe.