Door Closer

A device used to control the action of a door by use of either hydraulic pressure, high tension spring, electrical devices, or air pressure. Single acting door closers operate doors which swing in one direction from frame to open and back to frame. Double acting door closers operate doors which swing in both directions, the closing point is the frame. A positive centering door closer is a double acting door closer which is specifically designed to stop at the dead center of the door frame every time. Also known as a Door Check