Flammable liquid - sparks
Flammable liquid - sparks
(OP)
Dear All,
I am in the process of installing a pressure transmitter on a toluene tank (highly flammable).
A question came up regarding the fact that when opening the 4" nozzle to install the transmitter sparks could develop by something being dropped.
The technicians already use no-spark tools to work on this tank.
What can be done to handle the installation of a new instrument on this tank nozzle that contains flammable liquid?
Are there any procedures identifying how to prevent these sparks? Any particular special cautions?
Thank you!
I am in the process of installing a pressure transmitter on a toluene tank (highly flammable).
A question came up regarding the fact that when opening the 4" nozzle to install the transmitter sparks could develop by something being dropped.
The technicians already use no-spark tools to work on this tank.
What can be done to handle the installation of a new instrument on this tank nozzle that contains flammable liquid?
Are there any procedures identifying how to prevent these sparks? Any particular special cautions?
Thank you!





RE: Flammable liquid - sparks
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Flammable liquid - sparks
Thanks!
RE: Flammable liquid - sparks
RE: Flammable liquid - sparks
RE: Flammable liquid - sparks
RE: Flammable liquid - sparks
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Flammable liquid - sparks
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Flammable liquid - sparks
Good luck,
Latexman
To a ChE, the glass is always full - 1/2 air and 1/2 water.
RE: Flammable liquid - sparks
If only once, consider inerting the tank with something dense like CO2 or argon to reduce the risk while doing the installation.
If this is a routine operation, consider a way to avoid having to do it- install it and valve it off for instance when not required.
Toluene is NOT "highly carcinogenic"- you're thinking of benzene, which can be shown to be a contributing cause to a very specific cancer (aplastic anemia). Toluene is widely used in consumer products. Benzene is not. The primary concern here is the flammability, and that's a very serious concern.
RE: Flammable liquid - sparks
The toluene tank in question is not under pressure during normal operation. The tank is set up with a Flame Arrester that has adequate capacity for these scenarios:
Pressure relief for accidental line clearing into tank using utility N2
Pressure relief for maximum fill-in rate + thermal outbreathing
Vacuum relief for maximum pump out rate + thermal inbreathing
We also have a Blowoff Manway with 1.0 psig set pressure. (Tank is rated 3 psig.) It operates at amb temp.
The Toluene tank is an above ground tank that has a capacity of ~ 15,000 gallons. Design Temp and Pressure = 200F & 3 psig. This tank is located inside a containment area that provides for containment in the event of a large spill. Whenever routine maintenance is performed on the system, personnel must use spark resistant tools. In line spark arrestor is installed on the inside of the off-loading line and a flame arrestor is designed on the top of the storage tank to prevent outside flame sources from entering the storage tank vent.
The tank is also set-up with Fire Safe Valves on Suction to each pump. Fusible linked valves provide protection in the event of an external fire. If temp reaches 165F, valves automatically CLOSE and shuts off toluene flow to the process.[Not to be confused with in line spark arrestor & vent flame arrestor also installed to keep external fires from entering into the toluene storage tank.]
* The main reason to install a pressure transmitter is to comply with a new plant initiative to monitor design limit exceedances, therefore the transmitter. The maintenance superintendent voiced a concern about sparks during the installation of the instrument and I was just wondering if other sites have a good way of handling this.
Thank you all for your comments and ideas.
RE: Flammable liquid - sparks
RE: Flammable liquid - sparks
RE: Flammable liquid - sparks
RE: Flammable liquid - sparks
The selected instrument meets the requirement for flammability.
Thanks again.
RE: Flammable liquid - sparks
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P.E. Metallurgy, Plymouth Tube
RE: Flammable liquid - sparks
With respect to frictional heat or sparks, it is recognized that there is a need to control sources of ignition, including mechanical sparks from hand tools, that have sufficient energy to ignite flammable vapors. Studies, anecdotes, codes, and referenced standards (e.g., API 2214, Spark Ignition Properties of Hand Tools) show that there is a potential for hand tool sparks to ignite flammable vapors from a limited number of chemicals and under certain unique conditions. These include flammable liquids with low minimum ignition energies, operations in which flammable or combustible liquids are heated, and a typical spark generation that can occur between specific types of hand tools and struck surfaces (i.e., thermite reactions or impact of steel tools on quartzitic materials).
Even spark-resistant tools might not provide suitable protection against ignition. For example, hard metal particles can become imbedded in the relatively soft metal of spark-resistant tools, and these particles can cause sparks when the tools are used.
Over the years, it has become more accepted that ordinary steel hand tools cannot generate ignition-capable sparks, except under unusual circumstances. (See API RP 2214, Spark Ignition Properties of Hand Tools.)”
RE: Flammable liquid - sparks
I will also share this info with our I&E and mechanics in the plant.
Greetings