[1] British Standards Institution. Industrial thermo-process equipment Part 2: Safety requirements for combustion and fuel handling systems: BS EN 746-2:2010 [S]. London: British Standards Institution, 2010: 39.
[2] American Petroleum Institute. Instrumentation, control and protective systems for gas fired heaters: API RP 556—2011[S]. Washington, DC: American Petroleum Institute, 2011: 16-18.
[3] National Fire Protection Association. Boiler and combustion systems hazards code: NFPA 85—2019 [S]. Quincy: National Fire Protection Association 2019: 27.