Compressed Gases & Cryogenic Liquids Handling

Compressed Gas Handling

1. Type of compressed gas.

2. Why compressed gas is hazardous ?

3. Prevent accident cause by pressure.

4. Prevent accident cause by gas.

5. Prevent accident cause by cylinder.

6. Safety operating procedure

wpe1B.jpg (2254 bytes)

Mr.David Chan


Cryogenic Liquid Handling

1. Types of cryogenic liquid

2. Why cryogenic liquid is hazardous ?

3. Precaution when using cryogenic liquid.

4. Transporting cryogenic liquid containers.

5. Transferring cryogenic liquid nitrogen.

6. Treatment on Cold Burn.

7. Treatment on Asphyxiation


Compress Gas Handling

Type of Compressed Gas

Stored in gas form inside the cylinder. e.g.

        =>Oxygen, hydrogen, nitrogen, helium.

Store in liquid form inside the cylinder e.g.

        =>Carbon dioxide, sulfur hexafloride.

Dissolve in other solvent. e.g.


Why Compressed Gas Is Hazardous ?

High pressure inside the cylinder.

The gas inside the cylinder may be:

        =>Flammable / Explosive.   

        =>Toxic / Corrosive.


The cylinder is also hazardous itself 

Handling of compressed gas:

A: Prevent the accident caused by the pressure inside the cylinder

l. Use suitable gas regulation.

    You have to know:

    Pressure. (Cylinder / Working)wpe1C.jpg (4971 bytes)

    Material Compatibility.

    Condition of the equipment.

2. Proper installation of gas regulator:

    Check cylinder connection.

    (Cylinder outlet / Regulator adaptor)

    Clean the cylinder valve.

    Tighten the fitting with suitable tools.

Test for Leakage Before Use.


B: Prevent the accident caused by the gas.

Understanding the gas inside the cylinder.

    Make sure the gas is the one you want.

    Check the label / Color of the cylinder.

    Never use the gas without proper labeling on the cylinder.

    Get information about the gas properties.

C: Prevent the accident caused by the cylinder.wpe1D.jpg (3637 bytes)

Since the cylinder is very heavy so :

1. When you need to relocate the cylinder, you must

    Use PPE

    Use specially designed tools--- cylinder trolley.

    Never roll the cylinder.

    Always shut the valve before moving.

2. To prevent falling, use specially designed tools to hold the cylinder on its place.

Safety operating procedure

1. Goods receiving:wpe1E.jpg (6211 bytes)

    Check the gas is the one you wanted.

    Check the sealing on the cylinder outlet.

    Check the cylinder valve.

    Check the label / Cert. on the cylinder.

2. Moving- the cylinder to using point.

    Use cylinder trolley to transport the cylinder.

    Use cylinder belt / rack to hold the cylinder

3. Using Area

    Well ventilation.

    Arranged so as to minimize fire risk.

Provided with appropriate safety and emergency equipment. e.g.wpe1F.jpg (4643 bytes)

    =>Fire extinguishers.

    =>Breathing apparatus.

    =>Eye protection.

4. Using the gas.

    Use suitable tools to fit the regulator.

    Clean the cylinder valve outlet and regulator inlet.

    Close the regulator before opening the valve.

    Use proper key to open the cylinder valve slowly.

    If the valve was damaged, never attempt to take gas from that cylinder.

5. Storage of cylinder.

    Keep the cylinder on a clean tidy area

    Keep the cylinder away form fire.

    Store gas by its type. Leave at least 3 meter for the flammable gas and oxygen.

    Full cylinder and empty cylinder should be kept in different place.

    Never smoke inside the compressed gas stores.


Cryogenic Liquid Handling

Types of cryogenic liquid

Liquid nitrogenwpe20.jpg (7263 bytes)

Liquid oxygen

Liquid argon

Liquid helium

Why Cryogenic Liquid is Hazardous

Cryogenic liquid is extremely cold. (Cold burn)

Very small amounts of liquid can convert into very

large amount of gases. (Asphyxiation)

Precaution when using cryogenic liquid.

1. Preventing cold burn

    Face shield or safety goggles.

    Thermal insulated glove.wpe21.jpg (4448 bytes)

    Overall clothing

    Handle with care

2. Preventing asphyxiation.

    Good ventilation.

Transporting cryogenic liquid containers.

Use proper transportation means:

Roller base (For dewar)

Trolley (For LGC)

Always put your PPE on even if your won't contact the liquid.


Transferring cryogenic liquid nitrogen.

Use proper withdraw device or dewar tipper.

Use phase separator.

Use gaseous nitrogen as pressure source.

Transfer at low pressure, usually less than 5 psig.

Always put your PPE on even your won't contact the liquid.


Treatment on Cold Burn

The following are recommended:wpe22.jpg (6916 bytes)

Untight covering clothing.

Do not rub frozen parts.

Wash with warm water.

Cover frozen parts with dry sterile clothing.

No alcohol or cigarette for patient.

Warm drink and food may be helpful.

Medical assistance should be obtained as soon as possible.


Treatment on Asphyxiation


        =>Slow down of physical and mental response.

        =>Unreasonable behavior.wpe23.jpg (4754 bytes)

        =>Rapid and gasping breathing.

        =>Collapse of incapacity to move.


        => Remove patient to open air.

        => Artificial respiration if necessary.



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