... -back Chamber (Wet-Back) 4.Safty Control System Product Features of WNS Oil/Gas-fired Steam Boiler1. This horizontal wet-back boiler ... , including light oil, heavy oil, residual oil, natural gas, coal gas, and liquefied petroleum gas;8. The thermal efficiency rises up to 90 ... , textiles companies, recycling firms, disinfection and metallurgical industries. WNS Oil/Gas-fired steam Boiler