Safety Matters - Protective Materials for Hot Work-Welding Blankets
The cost a major fire in a refinery or chemical plant can be very high, not including lost production and litigated damages. The welding
blanket that could have prevented the fire could have cost a few hundred
dollars.
Purpose of welding/fire blankets: Fire blankets protect persons, property, and
equipment when exposed to welding spark, spatter, or high heat that could result
in expensive damages including major fires.
In major plant shutdowns and new construction, welding blankets are used as equipment covers to
protect sensitive equipment and instruments from the potential damage that can
be caused by welding splatter coming into contact with the equipment. Catwalks
should be lined with welding blanket material to prevent welding spark and
spatter from falling onto other levels and potentially igniting fires where
there may be petroleum spills or simply keeping the spark from landing on
persons working on lower levels.
Do you comply with OSHA Hotwork Standards?
Here is part of the USA, OSHA, Code of Federal Regulations (CFR)
1910.252.
1910.252(a)(1)(i)
Fire
hazards. If the object to be welded or cut cannot readily be moved, all movable
fire hazards in the vicinity shall be taken to a safe place.
1910.252(a)(1)(ii)
Guards. If the object to be welded or cut cannot be moved and if all the fire
hazards cannot be removed, then guards shall be used to confine the heat,
sparks, and slag, and to protect the immovable fire hazards.
1910.252(a)(1)(iii)
Restrictions. If the requirements stated in paragraphs(a)(1)(i) and (a)(1)(ii)
of this section cannot be followed then welding and cutting shall not be
performed.
1910.252(a)(2)(i)
Combustible material. Wherever there are floor openings or cracks in the
flooring that cannot be closed, precautions shall be taken so that no readily
combustible materials on the floor below will be exposed to sparks which might
drop through the floor. The same precautions shall be observed with regard to
cracks or holes in walls, open doorways and open or broken windows.
Similar
Standards are in effect worldwide.
What to look for in
a Welding Blanket!
Toxicity – Smoke and
Flame-Ensure that the materials you use are within threshold limit values when
the materials are exposed to high temperature or splashed slag. In general
products such as neoprene, urethane, Hypalon® (chlorosulfonated
polyethylene),
acid leached materials, and plastics family products have difficulty meeting
Occupational Health & Safety standards.
Solvent resistance – It
is important for welding blankets used in environments where solvents, oils, or
chemicals may be present; that the materials used resist absorbing liquids. A
welding blanket that absorbs solvents can quickly turn into a carrier of fire.
Look for tiny pinholes or a non-sealed weave. Solvents and oils enter the fabric
through imperfections caused by the coating/curing process. Lightweight products
have less protective coating creating voids and more potential for wicking of
solvents. Uncoated fabrics should never be used as welding blanket for projects
where flammable liquids can be wicked and be the source of a fire.
Temperature claims-
Be aware that specifications regarding temperature limits are for the
blanket as a system. Many temperature specifications are listed for the base
fabric and not the protective coating. It does no good to use a material rated
for 1000 °F
with a coating that ignites at 450
°F.
Vertical or horizontal placement of welding blankets calls for different
temperature limits. Horizontal applications of welding blanket can be subject to
much higher temperatures because weld splatter and slag can lay on its surface
for extended periods of time.
Friendly
to work with -
For your specific use, is the material easy to walk on if used on catwalks etc
(non slip)? Does it fray when cut (thus exposing loose fibers and unraveling)?
Is it drapeable, water resistant, washable, easy to cut to size, easy to shape,
etc? Have your welders use the material and provide the practical feedback as to
which material best suits their needs.
Paperwork - Request manufacturer specifications on the materials you propose to
use, including MSDS sheets, and do comparisons.
Safety is the number one priority – ensure the welding blanket material you
choose meets your checklist of requirements.
Make
sure the welding blanket allowed onsite is in your maintenance and construction
specs for Hotwork. Be sure the material you specify is what ends up on your
jobsite.
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