Toolbox Topic: Industrial / Compressed Gases
Compressed gases can be extremely dangerous, as we will see when discussing actual events in today’s episode. Also, we will cover ways to stay safe when working with industrial /compressed gases.
Definitions
Industrial gases are gases manufactured for use in industry. Industrial gases can include nitrogen, oxygen, carbon dioxide, Argon, hydrogen, helium, and acetylene.
Compressed gasses are those stored under pressure in cylinders. The pressure in a gas cylinder is usually recorded as pounds per square inch. The three major types of gases include compressed, liquefied, non-liquefied, and dissolved.
History of Industrial Compressed Gases
The history of industrial gases is the history of chemistry. In ancient Greece, many philosophers believed that there were four basic elements earth, water, air, and fire. Today we recognize these as states of matter, including solid, liquid, gas, and plasma.
Around 300 BC, Greek philosophy and Egyptian metallurgical tradition intersected, creating alchemy. Alchemists erroneously theorized the “philosophers Stone” (a substance that could transmute metals) transforming metals such as iron or lead into gold.
Late in the 17th century, many scientists began experimenting with gases. The increased interest in gases led to the development of pneumatic chemistry.
In the 18th century, the industrial revolution propelled science even further. Many gases were identified and either discovered or first made in (mostly) pure form. The collaboration between chemists and industrialists proved crucial in commercializing industrial gases.
In 1754 a Dutch chemistry teacher discovered Carbon Dioxide.
In 1766 Henry Cavendish discovered hydrogen but didn’t know it at the time. In 1781, Cavendish found that he could create water by combining hydrogen and oxygen. Only years later would hydrogen have a proper place in chemistry and get its official name which means “producing water.”
In 1844 nitrous oxide was first used for dentistry.
Initially used for lighting and welding, Acetylene would launch the industrial gas business.
By the 19th century, gases had found uses in food, refrigeration, medicine, fuel, lighting, fertilizers, fire extinguishers, fizzy drinks (coca cola uses carbonated water), and even flight (the Hindenburg).
Today industrial gases are used in a wide range of industries, such as oil and gas, power, chemicals mining, steelmaking, metals, pharmaceuticals, biotech, electronics, and aerospace.
Safety Tips
Safety Tip # 1 Safe Handling and Use
Compressed gases must be handled and used only by trained employees. Always consult the gas manufacturer’s safety data sheets (SDSs) for specific information.
Safety Tip #2 Clearly Identify Cylinders
Labels must not be defaced or removed. Do not accept or use containers whose content labels are not legible. Do not use the container’s color to identify the cylinder’s content. Do not repaint containers. Clearly label all gas lines leading from a compressed gas supply.
Safety Tip #3 Valve Protection Caps
Leave valve protection caps in place until cylinders are secured and connected. Keep cylinder valves closed except when the cylinder is being used. Closing the valve prevents corrosion and contamination. When opening a cylinder valve, ensure it is pointed away from yourself and others. Slowly open the valves.
Safety Tip #4 Tampering
Never tamper with or alter cylinders, valves, or safety relief devices.
Safety Tip #5 Transporting Cylinders
Do not drag or slide cylinders. Do not lift cylinders by the caps. Secure the cylinder and move it with a hand truck, lift truck, or crane with a cradle or platform. Do not use lifting magnets. Slings, ropes, or chains are acceptable if cylinders are equipped with lifting attachments. Never drop cylinders or strike them against one another or other surfaces.
Safety Tip#6 Secure and Store Cylinders Properly
The gas inside an oxygen cylinder is compressed to 2,200 pounds per square inch (psi), yet the wall thickness of this cylinder is only one-quarter of an inch. If the cylinder falls over and the valve breaks, the gas will escape through an opening about the size of a pencil. This minor incident will turn that gas cylinder into a rocket, which can go through walls, ricochet, spin, and damage anything in its path. So always secure gas cylinders to avoid tip over.
Group and store compressed gases based on their hazard class. Provide adequate space or segregate by partitions. Post conspicuous signs that identify the gas or hazard class. Store full and empty cylinders apart. Always handle empty cylinders as though they are full.
Storage areas should be dry, well-drained, ventilated, and fire-resistant. Avoid sub-surface storage. Cylinders can be stored in the open, but they should be protected from rusting. Prevent exposure to salt, corrosive chemicals, or fumes. Cylinders stored in the sun must not exceed temperatures above 125 F.
Always refer to the manufacturers’ storage requirements and SDSs. Storage areas should protect cylinders from damage. Do not store on unprotected platform edges or obstruct walkways or exits.
Safety Tip #7 Inspect Cylinders
Inspect for exterior corrosion, denting, bulging, gouges or digs. Take leaking regulators, cylinder valves, or other faulty equipment out of service. Return questionable cylinders to the gas supplier.
Safety Tip #8 Know the dangers of Compressed Gases
The primary hazard for acetylene and propane is flammability; both are secondarily asphyxiants.
Argon and carbon dioxide are asphyxiants. Asphyxiants (including inert gases) can displace oxygen and may cause suffocation.
Corrosive and toxic gases present serious hazards: keep exposures as low as possible and avoid inhaling or contact with skin or eyes.
Safety Tip #9 Assess your shop
Look around. Are Gas Cylinders Stored properly?
Are valve protection caps in place?
Are all gas cylinders secured to prevent tip over?
Are cylinders properly segregated?
Empty or full and by type?
Safety Tip #10 Fuel Gas and Oxygen Cylinders
Acetylene is a gas that is almost universally used for welding. When mixed with oxygen, Acetylene burns at temperatures exceeding 5000 degrees Fahrenheit. Always store acetylene cylinders at least 20′ from oxygen cylinders. Suppose 20′ of separation is impossible: In that case, gases should be separated by a five-foot (minimum) non-combustible (half-hour fire-rated) partition, such as a metal barrier.
Sources:
Almqvist, Ebbe. History of Industrial Gases. New York, Kluwer Academic/Plenum Publishers, 2003.
https://en.wikipedia.org/wiki/Industrial_gas
https://safety.uoregon.edu/compressed-gases
https://osha.oregon.gov/OSHAPubs/factsheets/fs09.pdf
https://dmse.mit.edu/sites/default/files/imce/research/safety/Gas_Cylinder_Safety.pdf