Is copper tubing permitted to be used for fuel gas distribution in Massachusetts?
The installation of fuel gas systems in Massachusetts is governed by the 248 CMR Massachusetts State Plumbing and Gas Fitting Code in which unlined copper tube is not permitted for natural gas transmission or distribution. Although the code references the allowable use of tin lined copper tube for fuel gas applications, 248CMR also references NFPA 54, which is the National Fuel Gas Code, and this code does allow the use of copper tube for fuel gas if the gas supplied contains less than 0.3 grains of hydrogen sulfide per 100 standard cubic feet of gas. Elevated levels of hydrogen sulfide in the gas stream can react with copper tube and can cause flaking of copper oxides on the inside of the tube.
