What can i make from this?
'I have a whole bunch of "expansion tanks" that I would like to use for something but don't know exactly what to make from them. They are about 12" wide maybe 15" high, spherical, have a bicycle style filler valve on one side, a threaded hole on the other (approximately 1" male pipe thread) and they hold 12 liters. They have a rubber bladder inside. the original use was as an accumulator on a cooling system. Other than cutting it in half and using it for a small grill I don't have any other ideas. They are rated for 3 bar of pressure (about 45 PSI) working pressure. The exact thing I have is in this PDF. http://www.reflex.de/reflex/pdf_engl/PI0106e_4_9571018_reflex_engl.pdf