In my woodworking workshop I am using HT DN50 tubes to connect the vacuum cleaner with the different tools like e.g the table saw.
In order to steer the airflow I designed this valve consisting of the valve housing and a slider.
Bottom and top side can be printed with either male or female connectors. The male one (=tube) can have either outer or inner diameter. With outer diameter it would fit inside a standard DN50 female tube connector. With inner diameter it fits into the regular tube. The female connector accepts a regular DN50 tube.
I printed with support within the housing. The support can be stemmed out in slider direction. It might need a little force. The front of a flat file has just about the right size for this.
The slider should be a little smaIler than the slider opening. Set the delta according to the precision of the printer. If it still fits too tight: a little bit of filing helps.
The design is customizable, and might be altered for other tube sizes. However I printed it only for DN50.