Facility Siting of Pressurized Liquidfied Flammable Gas storage tanks

As we have discussed, OSHA does not have a “flammable gas” standard for those flammable gases outside the scope of its Liquefied Petroleum Gas (LPG) standard 1910.110.  So in most of my work with flammable gases, I will use 1910.110 or NFPA 58 as my RAGAGEP.  I do this as many facilities already have some fundamental understanding of LPG hazards.  This all starts with “siting” the storage tank.  To make this easier to understand, I love to use WI-OSHA (LNI) standards as they are written in “plain English”.  So let’s discuss what our “siting” requirements look like in regards to protecting the storage tank from its greatest risk… BLEVE:

• Do NOT stack containers installed for use above the other.
• In industrial installations involving containers
  • of 100,080 gallons of aggregate water capacity or more,
  • where serious mutual exposures between the container and adjacent properties prevail,

firewalls or other means of special protection designed and constructed in accordance with good engineering practices are required.

• In the case of buildings devoted exclusively to gas manufacturing and distributing operations, the distances required by Table H-23 may be reduced provided that in no case you locate containers of water capacity exceeding 500 gallons be located closer than 10 feet to such gas manufacturing and distributing buildings.
• Ensure readily ignitable material such as weeds and long dry grass are NOT within 10 feet of any container.
• The minimum separation between liquefied petroleum gas containers and flammable liquid tanks must be 20 feet, and the minimum separation between a container and the centerline of the dike must be 10 feet.

NOTE: This does not apply when LP-gas containers of 125 gallons or less capacity are installed adjacent to Category 4 flammable liquid tanks of 275 gallons or less capacity.

• Take suitable means to prevent the accumulation of flammable liquids under adjacent liquefied petroleum gas containers, such as by diking, diversion curbs, or grading.
  • When dikes are used with flammable liquid tanks, you must NOT locate any liquefied petroleum gas containers within the diked area.

 Critical Distances

Locate each container with respect to the nearest important building or group of buildings or line of adjoining property which may be built on.

Source: https://lni.wa.gov/safety-health/safety-rules/chapter-pdfs/WAC296-24.pdf