These are our in-channel checks to hold water up in different sections. Commonly we attach these to a length of poly pipe and bury in the channel which can also be used for a crossing. These outlets range from 315mm – 1000mm depending on flows required. We also do the pipe send stops with a winder mechanism for ease of opening when there may be higher head pressure on the door or in the larger size pipes. We also use the winder doors to retro fit onto existing concrete headwalls. It must be noted to the customer that these doors are only designed to stop water one way (water pressure pushing against the door). If you try to do it the other way it will push the door out of the rubber guides.