The invention relates to a fluid valve comprising: a body defining a fluid flow duct, and a flap that can move between a closed position preventing the fluid from flowing through the duct and an open position allowing the fluid to flow through the duct. If an edge direction does not have a certain minimum length, then that direction is filtered out and a default direction is provided. In particular, if a user is accidentally injured by a blood-stained needle, serious infections might be caused through the needle.