If you need some flat design ideas, try out this Hydropower Pipeline SVG icons. It looks good and it will help you improve your own graphic works or website.
You have the download buttons bellow and can choose between two popular extensions, SVG or PNG formats. Also, before downloading the Hydropower Pipeline SVG icon, you can try the colors from the top of the icon, and test it, if the color fit with your ideas. If not, just refresh the page and you'll have new posibillities