Hazardous Materials Operations

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Highway Tankers
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Types of Tankers

• There are four types of tankers
• Flammable liquid tankers
• Compressed gas tankers
• Corrosive liquid tankers
• Cryogenic liquid tankers

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• Flammable liquid tankers are the most common type
  of tanker presently hauling hazardous materials

They have a very distinctive silhouette
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Design Features of Flammable Liquid Tankers
Common features slightly oval in shape flat
or blunt ends ladder to access personnel
walkway across top
Dome covers on top function as emergency
relief devices covers are actuated by a
fusible link dome covers are NOT self-closing
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Design Features of Flammable Liquid Tankers

• Off-loading is performed through bottom valves

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Design Features of Flammable Liquid Tankers
Emergency shutoffs may be either manual or air
pressure actuated
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Design Features of Flammable Liquid Tankers
Construction is usually aluminum, but some are
light weight stainless steel
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Design Features of Flammable Liquid Tankers
The tanker MUST have an identification
inspection plate installed on either side, toward
the front, that contains the model number of the
tanker
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Design Features of Flammable Liquid Tankers
Model numbers
MC - 303 MC - 304 MC - 305 MC - 306 MC
- 307

• These are the DOT model numbers for various types
  of flammable liquid tankers

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Design Features of Flammable Liquid Tankers
Emergency responders should familiarize
themselves with these tankers their unique
features, general appearance likely contents

• cannot contain pressurized gases
• most likely to contain flammable or combustible
  liquids
• may contain non-flammable liquids like milk or
  molasses
• not likely to contain corrosives
• BLEVE potential is minimal

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• Compressed gas tankers are the second most common
  type of tanker presently hauling hazardous
  materials

They have a very distinctive silhouette
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Design Features of Compressed Gas Tankers
Common features diameter is perfectly round
evenly rounded ends construction is high grade
steel that varies from 1/2 to 1 inch

• at least one sometimes
• two PRVs (pressure relief
• valves)
• PRVs are spring loaded, self-closing recessed
  into the top of the tank for rollover protection

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Design Features of Compressed Gas Tankers

• Loading off-loading performed through bottom
  valves

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Design Features of Compressed Gas Tankers
Emergency shutoffs are generally spring-loaded
and are normally located near the offloading
ports...
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Design Features of Compressed Gas Tankers
...and occasionally near the cab
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Design Features of Compressed Gas Tankers

• The tanker must have an identification
  inspection plate installed on either side, toward
  the front, that contains the model number of the
  tanker

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Design Features of Compressed Gas Tankers
Model numbers
MC - 330 MC - 331

• These are the DOT model numbers for the various
  types of compressed gas tankers

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Design Features of Compressed Gas Tankers
Emergency responders should familiarize
themselves with these tankers their unique
features, general appearance likely contents

• will have pressurized gases
• unlikely to contain flammable liquids
• will NOT contain cryogenics
• BLEVE potential is very high

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• Corrosive tankers are the third most common type
  of tanker presently hauling hazardous materials

They have a very distinctive silhouette
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Design Features of Corrosive Tankers
Common features have relatively blunt ends,
with some roundness much smaller in diameter
than a pressure vessel can be very long

• have several (up to ten) reinforcing rings
  encircling the exterior of the tank that add
  strength to the tank
• construction materials vary
• frangible disc on top, not self-closing

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Design Features of Corrosive Tankers

• Loading off-loading is performed through rear
  valves

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Design Features of Corrosive Tankers

• The tanker must have an identification
  inspection plate installed on either side, toward
  the front, that contains the model number of the
  tanker

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Design Features of Corrosive Tankers
Model numbers
MC-310 MC-311 MC-312

• These are the DOT model numbers for the various
  types of corrosive tankers

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Design Features of Corrosive Tankers
Emergency responders should familiarize
themselves with these tankers their unique
features, general appearance likely contents

• will have corrosives
• somewhat likely to contain a flammable liquid,
  like grain alcohol
• likely to contain poison liquid or oxidizing
  liquid
• will not contain pressurized gas
• BLEVE potential is moderate to high

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Cryogenic tankers are the fourth most common type
of tanker hauling hazardous materials

• Their silhouette is similar to a compressed gas
  tanker except for the rear box and the relatively
  blunt ends

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Design Features of Cryogenic Tankers
Common features diameter is round relatively
blunt ends construction varies larger in
diameter than a pressurized gas or flammable
liquid tanker

• has a large box or compartment mounted at the
  rear of the tank
• design features give the tank an appearance of
  immense size, but the inner tank rarely exceeds
  7,000 gallons

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Design Features of Cryogenic Tankers
Common features (continued) a frangible disc
is located at the top of the tank is not
self-closing equipped with a true
pressure-relieving device for emergency venting
in case of fire
equipped with a breather venting device,
similar to a PRV
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Design Features of Cryogenic Tankers

• Loading offloading is performed through rear
  valves

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Design Features of Cryogenic Tankers
Emergency shutoffs are usually spring-loaded and
located in the rear compartment and occasionally
near the cab
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Design Features of Cryogenic Tankers

• The tanker must have an identification
  inspection plate installed on either side, toward
  the front, that contains the model number of the
  tanker

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Design Features of Cryogenic Tankers
Model numbers
MC-338

• This is the only DOT model number for cryogenic
  tankers

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Design Features of Cryogenic Tankers
Emergency responders should familiarize
themselves with these tankers their unique
features, general appearance likely contents

• will have cryogenic liquids
• likely to contain corrosives
• likely to contain flammable gas
• likely to contain a poison or oxidizing liquid
• will not have pressurized gas
• BLEVE potential is very high

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Dry Goods Carrier