Electric boilers are covered in Section 1 of the ASME code. Within the code are two sections that apply to electric boiler production. The part PEB and part PMB define specific do and do not situations for fabrication and quality control. PEB is Power Electric Boiler, PMB is Power Miniature Boiler. The PMB applies only to vessels under 5 cubic feet volume, under 100 psi, under 16 inch diameter. Safety relief and hydro testing are mandatory with all boilers. Be sure you seek a reputable ASME stamped boiler. Safety may be compromised in other lesser cost and lesser designed products.