While messing around trying to create my pipe flanges, I've been opening and editing the generic fittings family. One of the parameters in these parts includes the tick mark size. By default it's a formula:
Tick Mark: Fitting Outside Diameter * 0.4
To make the tick mark smaller, change the mutliplier to a smaller value, i.e. 0.2 - this will make the tick mark shorter than what shows up by default. You'll need to make this change on any of the fittings you're using, so edit each type - to change, use project browser, go to families, go to pipe fittings, right mouse click on the fitting family and pick Edit. When the family is open, select Type on the far right side of the ribbon. Change the value in the formula and then pick OK. Next, use Load into Project to load it into your current project or template, and make sure you choose the Override family type and parameters option, to make sure the value is updated.
Try it out - and see if it makes your plumbers happier!
thanks - David B.