To define the orientation of a routing component such as a valve an axis is included in the component and a construction line in the 3D routing sketch. If the component that is inserted is a subassembly - say a valve with flanges - then the axis needs to be defined for the subassembly. In setting up these components I add a vertical axis in the part and in the subassembly making sure iti s the last item in the feature tree and vertical is spelt with a capital 'V'. On a number of occasions I've found errors in routing assemblies and on checking have found they are caused by the vertical axes being greyed out. In some cases the order of the axis in the feature tree is changed. Does any one else have this problem?