A method, apparatus, and computer instructions for leasing a unique digital item in a network data processing system. The pilot control system includes at least one fluid conduit, a variable orifice assembly, and a control pilot valve apparatus. In the printing system, the image forming apparatus includes an image forming; a print mode discriminating section; a confirmation result inputting section; and a request informing section. The mounting tab has a break away portion so that the plastic component can be removed for recycling easily. According to such a configuration, it is possible to sustain high output of the power generator irrespective of a differential pressure between primary side steam and secondary side steam.