I'm interested in Nationwide Boiler's ultra-low NOx solutions. Can you find information about their achievements in this area, specifically for a 350HP firetube boiler? Identify the Oilon ultra-low NOx burner model used and describe its key features that enable such low NOx emissions without requiring flue gas recirculation (FGR) or air filters.
Navigate to the 'Resource Center' from the homepage. Go to the 'Press Releases' section. Locate and open the press release detailing 2½ PPM NOx achievement for a 350HP firetube boiler. Identify the Oilon burner model name from the article. Extract the primary features or technology of the burner that enable ultra-low NOx without FGR or air filters. Synthesize the findings into a concise answer.
Successfully identifies and states the Oilon burner model name as 'LN30 (also known as the ULN2.5)'. Accurately describes that the burner is constructed with patent pending technology. Accurately states that it achieves single digit, ultra-low NOx with lower residual oxygen, no air filters, and no flue gas recirculation (FGR) while utilizing conventional gas delivery pressures.