Section 5586 - Low Pressure Tanks(a) The normal operating pressure of the tank shall not exceed the design pressure of the tank.(b) Low pressure tanks shall be built in accordance with approved standards of design. Low pressure tanks may be built in accordance with:(1) American Petroleum Institute Standard No. 620, Recommended Rules for the Design and Construction of Large, Welded, Low-Pressure Storage Tanks, Fifth Edition 1973.(2) The principles of the Code for Unfired Pressure Vessels, Section VIII, Division I of the ASME Boiler and Pressure Vessels Code, 1971 Edition.(c) Atmospheric tanks built according to Underwriters' Laboratories, Inc. requirements in Section 5585(a) may be used for operating pressures not exceeding 1 psig and shall be limited to 2.5 psig under emergency venting conditions.(d) Pressure vessels may be used as low pressure tanks.Cal. Code Regs. Tit. 8, § 5586