Buried Propane Storage Tanks 2

[chicopee]

Is anyone familiar with guidelines from such organization as the American Propane Association concerning the referenced subject? Also, how is the requirement for determining the relieving capacity of safety valves for such installation calculated- filling rates perhaps?

 

[stookeyfpe]

The requirements for buried underground stationary LP-Gas containers are found in NFPA 58, Liquefied Petroleum Gas Code. The vessels must meet the ASME BPV, Section VIII, Division 1 for underground service. If the container is designed as an interchangeable vessel (meaning it can be installed either underground or aboveground), it must be listed as meeting UL standard 644,Container Assemblies for LP-Gas. These containers are generally limited to a water capacity of 2,000 gallons or less.

Larger (> 2,000 gallons water capacity) can also be mounded. Mounding is providing a earth or aggregate cover of a code specified depth over an aboveground ASME pressure vessel.

In either underground or mounded applications, cathodic protection is required.

If the container is installed underground or mounded, NFPA 58 allows the flow capacity of pressure relief valves to be reduced to 30% of the flow rate specified in NFPA 58. The flow rate in CFM (air) = 53.632 x A^0.82, where A is the total outside surface area of the vessel measured in square feet.

Finally, if the installation is > 4,000 gallons water capacity, more extensive requirements in NFPA 58 are specified for excess flow control and loading/unloading connections.

One US trade association for LP-Gas is the National Propane Gas Association.

http://www.npga.org/i4a/pages/index.cfm?pageid=1

 

[joerd]

European guidelines are provided through EEMUA, in particular publication 190.

Cheers,
Joerd

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.