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TME 8 �. DIVISION OF INDUSTRIAL �FETY 582.3 UNFIRED PRESSURE VESSEL SAk.KrY ORDERS (Register 75. No. 15--3.2475) (b) A check valve shall be installed in lieu of the required excess flow f� valve on the fill connection, except when flow is needed in both direc- tions, and a remotely operated shutoff valve shall be installed on all other connections located below the maximum liquid level. (c) The filling density for refrigerated storage containers shall be such that the container will not be liquid full at a liquid temperature corresponding to the vapor pressure at the start-to-discharge pressure setting of the safety-relief valve. (d) Safety-relief valves shall be set to start-to-discharge at a pressure not in excess of the design pressure of the container and shall have a total relieving capacity sufficient to prevent a maximum pressure in the container of more than 120 percent of the design pressure. Relief valves for refrigerated storage containers shall be self-contained spring-load- ed, weight-loaded, or self-contained pilot-operated type. The total relieving capacity shall be the larger of: (1) Possible refrigeration system upset such as (A) cooling water failure, (B) power failure, (C) instrument air or instrument failure, (D) mechanical failure of any equipment, (E) excessive pumping rates. (2) Fire exposure determined in accordance with Compressed Gas Association (CGA) S-1, Part 3, Safety Relief Device Standards For Compressed Gas Storage Containers, 1959, except that "A" shall be the total exposed surface area in square feet up to 25-foot above grade or to the equator of the storage container if it is a sphere, = whichever is greater. If the relieving capacity required for fire expo- sure is greater than that required by (1) of this subdivision, the additional capacity may be provided by weak roof-to-shell seams in containers operating at essentially atmospheric pressure and having an inherently weak roof-to-shell seam. The weak roof-to-shell seam is not to be considered as providing any of the capacity required in (1) of this subdivision. If vent lines are installed to conduct the vapors from the relief valve, the back pressure under full relieving conditions shall not exceed 50 percent of the start-to-discharge pressure for pressure balanced valves or 10 percent of the start-to-discharge pressure for conventional valves. The vent lines shall. be installed to prevent ac- cumulation of liquid in the lines. The valve or valve installation shall provide weather protection. Atmospheric storage shall be provided with vacuum breakers. Am- monia gas, nitrogen, methane, or other inert gases can be used to provide a pad. (e) Appurtenances shall be protected against tampering and physi- cal damage. (f) Containers of such size as to require field fabrication shall, when moved and reinstalled, be reconstructed and reinspected in complete accordance with the requirements under which they were constructed. The containers shall be subjected to a pressure retest and if rerating is necessary, rerating shall be in accordance with applicable require- ments. (g) Precaution shall be taken against damage from vehicles.