Hard-piping
Hard-piping means piping or tubing that is manufactured and properly installed using good engineering judgment and standards, such as ANSI B313.
Source
40 CFR § 63.1251
Scoping language
Terms used in this subpart are defined in the Act, in subpart A of this part, or in this section. If the same term is defined in subpart A of this part and in this section, it shall have the meaning given in this section for the purposes of this subpart.