OK, I see what you mean. This happens because they use hover CSS menus on desktop that are not mobile optimized. And the delay is the default 300ms click delay before firing the click event that mobile browsers have when you tap a link on the page (browser makers are actually trying to remove that in many scenarios recently). I am not sure what you like about this but it makes the sub menus completely unusable to regular users that are not familiar with their contents. Can you read all the items in 0.3 seconds + plus a variable bit more (depending on your network connection, device and browser loading speed) and then choose the one you are interested in before the parent link is loaded automatically? Of course, not. What happens with further sub menu levels? Try choosing some item from the “Pipe installation” > “Products” sub menu (and remember you have no idea what the items are and first need to read them). I guess you see what I mean.
BTW, I guess you are testing with an older iOS version because in 8.1 I tested with, the first tap on the parent item “Products” activates the sub menu and only a second tap activates the link – it’s not activated automatically. This is obviously because they are trying to make similar non-mobile optimized pure CSS menus usable in some way.
I currently get the behavior you describe on Android (latest Chrome, Firefox and Opera) but as I mentioned, it makes the sub menus completely unusable to regular users.
