506.3.2.5 Grease duct test.
MC § 506.3.2.5
Prior to the use or concealment of any portion of a grease duct system, a leakage test shall be performed. Ducts shall be considered to be concealed where installed in shafts or covered by coatings or wraps that prevent the ductwork from being visually inspected on all sides. The duct installer shall be responsible for providing the necessary equipment and performing the grease duct leakage test. A duct leakage test, in accordance with this section, shall be performed for the entire duct system, including the hood-to-duct connection. The duct work shall be permitted to be tested in sections, provided that every joint is tested. To determine the tightness of the grease duct construction, a smoke test shall be made in accordance with the following conditions and requirements: 1. The test shall be performed in the presence of the special inspector.
2.The grease duct shall be filled with a thick penetrating smoke produced by one or more smoke machines, or smoke bombs. A static pressure equal to or not less than 2" wg shall be maintained throughout the test. The test shall be applied for a length of time sufficient to permit the inspection of the grease duct.
3.If the test shows any evidence of leakage or other defects, such defects shall be corrected in accordance with the requirements of this chapter, and the test shall be repeated until there is no visible smoke observed.
