We have discussed all the requirements for transferring flammable liquids and gases (i.e., NFPA Flammable “4”); however, I have not mentioned the requirements for transferring TOXIC and HIGHLY TOXIC LIQUIDS that have an NFPA 704 Health Rating of 3 or 4. We see these issues in our Chlorine work where Cl2 is a “utility” to the business and is sort of “out of sight – out of mind” until there is a LOPC event. Many facilities also overlooked their state fire code requirements as a great baseline RAGAGEP for their “primary containment” systems, such as piping.
The IFC provides us with some excellent baseline line designs that should be incorporated into our process, regardless of whether or not the State Fire Marshal enforces the requirements. We do these things to IMPROVE PROCESS SAFETY (not PSM/RMP compliance!), not to make the SFM happy.
(Emphasis by me)
SECTION 5005—USE, DISPENSING AND HANDLING
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5005.1.10 Liquid transfer.
Liquids having a hazard ranking of 3 or 4 in accordance with NFPA 704 shall be transferred by one of the following methods:
1. From safety cans complying with UL 30.
2. Through an approved CLOSED1 piping system.
3. From containers or tanks by an approved pump taking suction through an opening in the top of the container or tank.
4. From containers or tanks by gravity through an approved self-closing or automatic-closing valve where the container or tank and dispensing operations are provided with spill control and secondary containment in accordance with Section 5004.2. Highly toxic liquids shall NOT be dispensed by gravity from tanks.
5. Approved engineered liquid transfer systems.
Exceptions:
Liquids having a hazard ranking of 4 where dispensed from approved containers not exceeding 1.3 gallons (5 L).
Liquids having a hazard ranking of 3 where dispensed from approved containers not exceeding 5.3 gallons (20 L).
5005.1.11 Design.
Systems shall be suitable for the use intended and shall be designed by persons competent in such design. Controls shall be designed to prevent materials from entering or leaving the process or reaction system at other than theintended time, rate or path. Where failure of an automatic control could result in a dangerous condition or reaction, the automaticcontrol shall be fail-safe.
5005.1.12 Emergency isolation.
Where gases or liquids having a hazard ranking of Health Class 3 or 4, Flammability Class 4 orInstability Class 3 or 4 in accordance with NFPA 704 are carried in pressurized piping above 15 pounds per square inch gauge(psig) (103 kPa), an approved means of leak detection AND emergency shutoff or excess flow control shall be provided.
Where the piping originates from within a hazardous material storage room or area, the excess flow control shall be located within the storageroom or area. Where the piping originates from a bulk source, the excess flow control shall be located as close to the bulksource as practical.
Exceptions:
1. Piping for inlet connections designed to prevent backflow.
2. Piping for pressure relief devices.
1. The use of a solid or liquid hazardous material involving a closed vessel or system that remains closed during normal operations where vapors emitted by the product are not liberated outside of the vessel or system and the product is not exposed to the atmosphere during normal operations; and all uses of compressed gases. Examples of closed systems for solids and liquids include product conveyed through a piping system into a closed vessel, system or piece of equipment.