R 408.11293 Gas holders.

Rule 1293. (1) A gas holder shall be constructed on the gasometer principle, the bell being suitably guided. The gas bell shall move without a tendency to bind and shall have a clearance of not less than 2 inches (5.08 cm) from the shell. (2) The compressor or booster cutoff of a gas holder shall be located 12 inches above the landing point of the gas bell to prevent collapse of the bell. (3) A gas holder shall be located in a heated and ventilated room as prescribed in R 408.11292(2) and the Michigan Occupational Safety and Health Administration (MIOSHA) standards. When heat is not supplied, the gas holder seals shall be protected from freezing. (4) A means shall be provided to stop the generator feeding mechanism before the gas holder reaches the upper limit of its travel. A gas holder connected to only 1 generator shall have a capacity of not less than 1/3 of the hourly rating of the generator. (5) Protective devices shall be installed in each supply line when acetylene is used from a gas holder without an increase in pressure at some points but with increased pressure by a compressor or booster pump at other points. A low pressure protective device shall be installed between the gas holder and the shop piping, and a medium pressure protective device shall be installed between the compressor or booster pump and the shop piping (see FIGURE 2). Approved protective equipment is used to prevent all of the following: (a) Backflow of oxygen into a fuel gas supply system. (b) Passage of a flashback into a fuel gas supply system. (c) Excessive back pressure of oxygen in the fuel gas supply system. The 3 functions may be combined in 1 device or may be provided by separate devices. (6) A compressor or booster pump shall be located in a ventilated area away from sources of ignition. (7) A compressor or booster pump shall be provided with a pressure relief valve which will relieve at not more than 15 psig (103.5 kPa gage) as prescribed in R 408.11292(5). The discharge outlets of a compressor or booster pump shall be provided protective equipment as prescribed in R 408.11252. FIGURE 2