NYLON Pneumatic pressure Valve
This is a small pressure equalization valve. It's used to maintain air pressure between two drying chambers. It's made of NYLON as NYLON provides a single part permanent hinged flap as a part of NYLON's flexibility.
For more info on printing in NYLON see:
http://www.instructables.com/id/Combination-CNC-Machine-and-3D-Printer/