1 When gas boilers belonging to the category of special equipment undergo low-NOx retrofit, while complying with the relevant laws and regulations, the "Boiler Safety Technology Supervision Regulations" (TSG G0001-2012), "Boiler Energy Saving Technology Supervision and Management Regulations" (TSG G0002-2010) and its modification sheets must also be strictly implemented, Management Rules for the Use of Special Equipment (TSG 08-2017), Circular of the General Office of the General Administration of Quality Supervision, Inspection and Quarantine on Risk Warning for Gas Boilers (No. 2 of 2017), Circular of the General Office of the General Administration of Quality Supervision, Inspection and Quarantine on the Implementation of Special Requirements for Energy Conservation and Environmental Protection of Boilers in Beijing, Tianjin, Hebei and the Surrounding Areas (QIQ Office of Special [2017] No. 967) and other relevant national and municipal Technical regulations, standards, management system.

2 for only the replacement of the burner, does not involve boiler renovation and major repairs, and belongs to the category of special equipment gas boiler, boiler user units must first to the district special equipment safety inspection agency for boiler maintenance notification procedures, and in the low nitrogen retrofit project is completed in a timely manner after the completion of the safety, energy efficiency, environmental protection inspection and acceptance of the work, to ensure that all the indicators are compliant, up to standard. Boiler burners should be obtained in accordance with the law burner type test certificates and reports. Replacement, modification and commissioning of the boiler burner shall be the responsibility of the burner manufacturer or its directly authorized unit. Burner manufacturer or its directly authorized unit should be burner replacement, modification of whether the boiler safety performance of the impact of the corresponding safety responsibility, and issue a safety confirmation. To take direct authorization, the burner manufacturer should issue a formal authorization instrument.

3 only to replace the burner can not achieve the effect of low-nitrogen conversion, the need for overall replacement of the boiler, or the implementation of boiler renovation and major maintenance, and belongs to the category of special equipment, gas boilers, the need to be first to the district special equipment safety inspection agency for boiler construction to inform the procedures, the strict implementation of the first requirement, in accordance with the relevant provisions of the inspection and testing and the original boiler in a timely manner for the cancellation of the formalities as well as the use of the new boiler Registration procedures.

4 implementation of low-NOx transformation of gas heating boilers should be scientifically arranged construction schedule, set aside time for commissioning, inspection, acceptance, to ensure the normal and stable operation of the heating season.

5 In order to effectively prevent safety risks and accidents, comprehensive safety and environmental protection influencing factors, the following suggestions are made:

1. for in-use boilers above 7.0MW (evaporation capacity 10t/h), it is not recommended to adopt the remodeling method of premixed combustion.

2. for the center return combustion boiler, it is not recommended to adopt the modification method of replacing the burner.