(1) After September 14, 1990, welding of pressurized piping for LNG or other cryogenic or hazardous fluids shall comply with 49 CFR Part 192, Subpart E - Welding of Steel in Pipelines. Such welding shall conform to the restrictions expressed in the 220 CMR 112.62 in addition to other sound engineering and work practices.(2) Materials to be qualified by impact testing shall be welded using procedures that preserve the low temperature properties of the material.(3) Piping attachments shall be welded using procedures to prevent burn-through and stress intensification.(4) Oxygen-fuel gas welding is prohibited.(5) Marking materials used to identify pipe welds shall be compatible with the basic pipe material.(6) Any permitted die-stamping must be done with a die with edges blunted to minimize stress concentrations. Surfaces of components less than 0.25 inches thick may not be field die-stamped.Amended by Mass Register Issue 1432, eff. 12/11/2020.