StacksVerified U.S. regulatory reference

49 CFR §230.71

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
  1. (a)Frequency of testing. The compressor or compressors shall be tested for capacity by orifice test as often as conditions may require, but not less frequently than once every 92 service days.
  2. (b)Orifice testing criteria.
    1. (1)Compressors in common use, as listed in the following table, shall have orifice test criteria as follows:
    2. (2)For compressors not listed in the table in paragraph (b)(1) of this section, the air pressure to be maintained shall be no less than 80 percent of the manufacturer's rated capacity for the compressor.