Water tube boiler

A steam generator for generation of steam in a water tube boiler, comprising:

• a first upright header having an interior axial pathway adapted for communication with a heated water supply;
• a second upright header spaced a distance from said first header and defining a gap therebetween, said second upright header having an interior axial passageway;
• a first plurality of tubes having interior passages, communicating in sealed engagement between said axial pathway and said axial passageway;
• said first plurality of tubes forming a lower bank, each of said tubes of said lower bank having an angle of incline from a lower engagement point with said first upright header, to an upper engagement point with said second header;
• a second plurality of tubes having axial conduits therethrough communicating in sealed engagement between said axial passageway and said axial pathway;
• said second plurality of tubes forming an upper bank, each of said second plurality of tubes communicating at an inclining angle from a first end engaged to said second upright header to a transition point, adjacent to said first upright header;
• an end portion of each of said tubes of said upper bank between said transition point and an engagement of said tubes with said first upright header;
• and
• said end portion having a generally declining angle from said transition point to said engagement with said first upright header.