US Patent 7562670 Flat valve for orbital applications

A thin diaphragm valve includes a base plate attached to a valve attach plate. A diaphragm is positioned between the plates to move between open and closed positions. A spring can be provided between the diaphragm and a sealing flange of a pipe. Because no sliding friction occurs between sealing surfaces, wear is reduced and leakage is also reduced. A pierceable membrane can also be added to provide additional security.