Nitrogen safety in the patch are you trained

P bar Y Safety Consultants

Nitrogen Safety in the Patch


Why Take Precautions?

• The gas isn’t technically toxic, but it can easily start to replace oxygen in the air so your body can’t breathe in enough oxygen. This can cause affixation very quickly.

• Oxygen becomes a liquid at a higher temperature than nitrogen, so liquid oxygen can become encased in liquid nitrogen. These oxygen enriched environments can cause materials to burn rapidly.


GHS


Understand Hazards Associated with Nitrogen

• Your Safety• Safety of Others• Recognize Hazards• Take Corrective Action• Respect N2


Physical Properties of Nitrogen

• Boiling Point is -320.4 Fahrenheit• Liquid Density is 6.745 pounds per gallon• Heat required to convert liquid to 70 F Gas is

184 btu per pound• Expansion Ratio of liquid to Gas is

697 to 1One gallon of Liquid Nitrogen at -320.4 F

is equal to 93.11 scf/70 F Gas


Nitrogen in Air• Air contains 78% nitrogen, 21% oxygen and 1%

other rare gases• Nitrogen Gas is:

– Colorless– Odorless– Non-toxic or irritating– Does NOT burn or support combustion– Will NOT support life functions– A poor conductor of heat

• Oxygen supports combustion and life support • Oxygen equals 21% of the air you breath


• Liquid Nitrogen Hazards– Explosion Due to Rapid Expansion

• “boiling liquid expanding vapor explosion” (BLEVE)– improper venting on containers– faulty pressure-relief devices – accidental or unusual conditions

» an external fire» incident that may cause break in the vacuum which

provides thermal insulation

Liquid NitrogenSafety & Handling


The Cryogenic ThermometerShows extraordinarily cold nature of liquid nitrogen

• Oxygen -297.3 F• Carbon Dioxide -109.3 F• Nitrogen -320.4 F• Absolute zero -459.7 F• Water +212 F

Liquids can boil on the positive and negative side

of the temperature spectrum


Liquid Nitrogen Burn


Avoid Skin Contact

• Avoid touching or exposing skin to:– Liquid Leaking from Equipment

• Destroys tissue similar to high temp burn

– Cold Equipment surfaces– Freeze Burns

• PPE should be worn


PPE goes further than you think


First Aid on Site


Handling Liquid Nitrogen

• Avoid rough handling of liquid containers

• Liquid cylinders should only be moved with proper handling equipment.

• Prior to use, ensure the fittings on the regulator match the fittings on the liquid container

• Never use adaptors

• Never attempt to change or remove any fittings


Safety Precautions for handling Liquid Nitrogen

• Wear Protective Clothing at all times when working with nitrogen

• Never work around nitrogen without:– Hard hat– Safety glasses or safety goggles and a face shield– Loose fitting insulated gloves– Long sleeve shirts– Cuff-less trousers (worn outside of safety boots)– Hearing protection– Safety boots


Protect Your Eyes

• Liquid nitrogen causes immediate damage• EYE DAMAGE IS USUALLY BEYOND REPAIR• One drop liquid nitrogen to the eyeball could

damage the eyeball instantaneouslyOne second of unsafe practice you could be

blind for LIFE!


Acceptable Cryogenic Materials

• Copper and brass• Stainless steel of the 300 series and• Aluminum (open ended only – low PSI)

EXAMPLES OF CRYOGENIC COMPONENTSInner tank of a nitrogen tankNitrogen low pressure pipingNitrogen fluid endsNitrogen high pressure piping


Non-Cryogenic Material

• Examples of Non-cryogenic material:– Carbon steels – which becomes brittle at

-40 F– Low alloy steels– Most Rubbers– Most plastics


Non-Cryogenic Components

• Examples of Non-cryogenic components:– Treating iron – made of carbon steel

(liquid nitrogen should never be allowed to enter or flow through it)

– Cryogenic tank casing and other components will crack when liquid nitrogen lands on the surface as these are made from carbon steel

(ex: when overfilling occurs)


Non-Cryogenic Components

Examples of Non-cryogenic (continued)Trailer framesPower trainsStructural componentsHydraulic linesTires


Treating Iron will NOT withstand Cryogenic Temperatures

• Allowing liquid nitrogen in the carbon steel treating iron is one of the most dangerous mistakes – shock could cause treating iron to break like glass

• Carbon steel cannot withstand rapid contraction

• Treating iron must not be hit or moved while frozen


Liquid Air Hazard• Ambient air condenses on the cold surface

with -320 F liquid nitrogen in the pipe• Boiling point of nitrogen is lower that the

boiling point of oxygen• Condensed liquid air can result in puddles

containing approximately 52% oxygen• Oxygen-enriched air may cause non-

combustible material to become flammable and normally flammable material to burn a a highly increased rate


Nitrogen Expansion

• Nitrogen expands 697 times it’s volume in going from a liquid at -320 F to Gas @ 70 F


Effect of Trapping Liquid Nitrogen

• Liquid nitrogen has a 697 to 1 expansion ratio

• It is important to note the pressure difference with temperature increase, in a closed container


Effect of Trapping Liquid Nitrogen

• Trapped liquid nitrogen will absorb heat and can exert pressure in excess of 21 tons per square inch

• Any place nitrogen can be trapped, a rego safety or popoff is used


Symptoms of Oxygen Deficiency

• Cold nitrogen gas will displace warmer air containing vital oxygen for breating in a confined space

• You need 21% oxygen for normal breathing and life support


Symptoms of Oxygen Deficiency (continued)

• Oxygen is necessary for us to live and function.

• Slight oxygen deficiency results in:– deeper respiration– Faster pulse– Poor coordination


Symptoms of Oxygen Deficiency (continued)

• As Oxygen deficiency INCREASES:–Ones judgment becomes poor

• He may or may not know to move to a well ventilated area


Gas Withdrawal

1. Connect a control regulator to the gas withdrawal valve and the outlet of the valve to the system receiving gas.

2. Open withdrawal and pressure building valves until the container reaches desire pressure.

3. You may begin withdrawing gas.


Liquid Withdrawal

1. Always wear a face mask for liquid withdrawal.2. Connect a transfer line from the liquid valve to

the system being filled.3. Open valve to desired rate of flow, close when

finished.4. To prevent back contamination, all valves should

be closed when the container has been emptied.


REMEMBER

• NITROGEN WILL DISPLACE OXYGEN WITHOUT WARNING

_________________________

Maintain proper ventilation to prevent asphyxiation


REMEMBER

• One full breath of pure nitrogen will strip blood of necessary oxygen resulting in a loss of consciousness


REMEMBER

• Always be cautious when there is a nitrogen gas cloud present.

• Never enter a gas cloud unless you are certain that it is NOT oxygen deficient

• If you suspect an oxygen deficient atmosphere – use company Confined Space Entry procedures and use appropriate breathing apparatus before entering


Always remember Hazards of Compressed Gases

ExplosionFlammability

CorrosiveToxicity

ReactivityAir displacing

Check SDS for specific hazards


Always remember Bulk Systems

• Built and maintained by qualified personnel• Filled by trained and qualified personnel• Tank and piping properly labeled• Tank system protected from damage


Always remember Cylinder Transportation

• Receiving/shipping cylinders requires DOT Hazardous Materials training

• Use lift trucks or hoists only with proper lifting equipment

• Never use a sling or electromagnet to hoist a cylinder

• Never lift a cylinder by the valve cap


Always remember Manual Cylinder Handling

Close the valve and put on the cap

Do not “walk” cylinder by holding onto valve

stem or capNever roll a cylinder

on its sideUse a hand truck with a secure system


Always remember Leaking Cylinders

Never try to repairTag it, move it

outdoors, and keep it away from heat

or flameCall manufacturer

or dealer

Presentations & Public Speaking

Nitrogen safety in the patch are you trained