It is nice when you add a valve to a pipe in single line and it inherits the color of the pipe. It's not so great when it also inherits the line type of the pipe when that line type is hidden. You get something that looks like this.
You can override the graphics in view of each of the valves to force the line type to continuous, but you are probably better off just creating a filter.
This one looks for all the pipe accessories in a view, then applies a solid override to the lines.
Done and Done.