Anyone involved with PSM/RMP knows about “facility siting” and all the attention it has gotten since the Texas City, TX incident in 2005. Many companies struggle with this type of analysis, so I am passing along some great data that could be used during an expansion project at an existing facility or for a new facility. PLEASE note that even if your process does NOT fall under PSM or RMP, this data should still be used as many states use NFPA 30 (or some version) as their flammable liquid code.
Chapter 17 is for “Processing Facilities” and the two sections that are most helpful are 17.3 and 17.4.
17.3 General Requirements.
17.3.1 Liquid processing operations shall be located and operated so that they do not constitute a significant fire or explosion hazard to life, to property of others, or to important buildings or facilities within the same plant.
17.3.2 Specific requirements shall depend on the inherent risk in the operations themselves, including the liquids being processed, operating temperatures and pressures, and the capability to control any liquid or vapor releases or fire incidents that could occur.
17.3.3 The interrelationship of the many factors involved shall be based on good engineering and management practices to establish suitable physical and operating requirements.
17.3.4 … N/A
17.3.5 … N/A
17.3.6 … N/A
17.3.7 When a process heats a liquid to a temperature at or above its flashpoint, the following shall apply:
(1)The process vessel shall be CLOSED to the room in which it is located and VENTED to the outside of the building.
(2)If the vessel needs to be opened to add ingredients, the room ventilation shall meet the requirements of Section 17.11 and the process heating controls will be interlocked with the ventilation such that the process heat will shut down if the ventilation fails or is turned off.
(3)The process vessel shall be equipped with an excess temperature control set to limit excessive heating of the liquid and the subsequent release of vapors.
(4)If a heat transfer medium is used to heat the liquid and the heat transfer fluid can heat the liquid to its boiling point on failure of the process and excess temperature heat controls, a redundant excess temperature control shall be provided.
17.4 Location of Process Vessels and Equipment.
17.4.1 … N/A
17.4.2 Processing vessels and buildings containing such processing vessels shall be located so that a fire involving the vessels does not constitute an exposure hazard to other occupancies.
17.4.3 The MINIMUM DISTANCE of a processing vessel to a property line that is or can be built upon, including the opposite side of a public way; to the nearest side of a public way; or to the nearest important building on the same property shall be one of the following:
(1) In accordance with Table 17.4.3
(2) Determined by an engineering evaluation of the process, followed by application of sound fire protection and process engineering principles
17.4.4 Where process vessels are located in a building and the exterior wall facing the exposure (line of adjoining property that is or can be built upon or nearest important building on the same property) is greater than 25 ft (7.6 m) from the exposure and is a blank wall having a fire resistance rating of not less than 2 hours, any greater distances required by Table 17.4.3 shall be permitted to be waived. If the exterior wall is a blank wall having a fire resistance rating of not less than 4 hours, ALL DISTANCES required by Table 17.4.3 shall be permitted to be waived.
17.4.5 All the distances given in Table 17.4.3 shall be DOUBLED where protection for exposures is not provided.
17.4.6* Liquid-processing equipment, such as pumps, heaters, filters, and exchangers, shall NOT be located closer than 25 ft (7.6 m) to property lines where the adjoining property is or can be built upon or to the nearest important building on the same property that is not an integral part of the process. This spacing requirement shall be permitted to be waived where exposures are protected in accordance with 17.4.3.
17.4.7 Processing equipment in which unstable liquids are handled shall be separated from unrelated plant facilities by either of the following:
(1) 25 ft (7.6 m) clear spacing
(2) A wall having a fire resistance rating of not less than 2 hours and explosion resistance consistent with the expected hazard
17.5 Accessibility. Each process unit or building containing liquid-processing equipment shall be accessible from at least one side for fire fighting and fire control.