The LX gas/low NOx Series high- or low-pressure steam boiler from Miura features the XJ1 micro-computer boiler control system. Featuring Miura's low water content watertube design, the LX is a once-through, forced circulation steam boiler producing steam in five minutes, while maintaining an 85% fuel-to-steam efficiency. The LX Series' design consists of rows of vertical tubes sandwiched between two rectangular headers. Both headers are encased in a castable refractory with only the tubes exposed to flame and/or combustion gases. The upper header is attached to the lower header by the tubes. As the tubes expand and contract, the headers float up and down accordingly. This concept reduces stress and allows for the use of cold feedwater without the fear of significant thermal shock. Miura Boiler Co. Ltd.