These open and close to regulate the flow of something - Word Hike answers

Are you looking for never ending fun in this exciting logic brain app? Word Hike is the new wonderful word game developed by Joy Vendor, known by his best puzzle word games on the android and apple store. Each pack has more than 15 levels. Some of the packs are: Departures, USA, France, Italy, Germany, Japan, Australia. We have also good news regarding the game: All the words were discovered by our team! We will share all of them and add new ones on a daily basis. Last but not least, if you are facing any difficulties in solving this "These open and close to regulate the flow of something" or any other Word Hike level, do not hesitate to leave a comment below. Please feel free to send us a comment below, if you are stuck at any level and cant find the right solution.