This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at

Subchapter 1. Unfired Pressure Vessel Safety Orders
Article 7. Compressed and Liquefied Natural Gas System

Return to index
New query

§529. Gauging Devices For Liquefied Natural Gas Tanks.

(a) A permanent dip pipe shall be installed in all LNG tanks filled by volume and shall be of such length that it will indicate when the tank is filled to the level specified by the manufacturer and in no case more than 90 percent. This fixed dip pipe shall be permanently installed in the tank. Additional dip pipes may be used providing they are permanently marked to show the outage they indicate.

(b) In addition to the fixed dip pipe required in (a) above, each LNG tank 60-gallon capacity or more, filled by volume, and each motor fuel tank shall be equipped with a liquid level gage.

(c) Gauging devices that require bleeding of the product to the atmosphere shall be so designed that the maximum opening of the bleeder valve is No. 54 drill size.

(d) Gauging devices shall be designed for the most severe pressure and temperature conditions to which the device may be subjected with a factor of safety of not less than 4. Such gaging devices shall be labeled with the maximum permitted pressure by the manufacturer.

(e) Where the efficiency of the insulation of an insulated tank is dependent upon the vacuum in an annular space, an indicating device or other means shall be provided to warn of loss of vacuum.

Go BackGo Back to Article 7 Table of Contents