An ultra-low-NOX boiler installed in California that can produce packaged steam consistently and predictably for 2 ppm NOX or less was installed at Pratt Industries in Lathrop, Calif. Boiler system maker Hurst Boiler Co. of Coolidge, Ga., partnered with Boiler & Steam Performance, Weishaupt Burner, California Boiler and Nationwide Boiler's CataStak SCR to configure and install the system.

The project involves a Hurst Series 500, 4-pass wet back scotch steam boiler with 250 psig steam design pressure operating at 200 psig steam. The natural gas fired, low-NOX burner does not have to use flue gas recirculation. The installed technology results in a boiler with low excess air, high turndown rates (which is critical in a corrugated box facility) and high boiler fuel to steam efficiency.