If you’re in the welding business (and want to make money at it), then you’re using high- pressure cylinders. If you’re using high- pressure cylinders then you’ve got a safety risk. And when you have risks, you want a plan to minimize the risk and maximize the reward…
One of the ways to manage risk is to dentify the worst-case scenario. For example, you’re a sports team playing against a much stronger team. You believe the worst-case scenario is to be scored on early in the game. It’ll give your opponents a psychological advantage and your team a psychological disadvantage. So, you take steps to essen the risk of getting scored on early: you encourage your players to think and behave more defensively early in the game, etc.
This way your stronger opponents aren’t going to score easily. Maybe your stronger opponents get frustrated, take unnecessary chances that creates chances for your team to score (maximizing the reward).
In the welding business, gas cylinder risk comes from only 2 areas: (1) outside (the physical cylinder) and (2) inside (the contents of the cylinder). The physical cylinder is heavy and awkward to handle. It has the ability to become a falling object or a self-propelled projectile or a bomb. The contents of the cylinder can create a minor scare or take your life away.
Minimize the Risk of the Physical Cylinder Dangers
1. Keep the cylinder away from sparks, flames, excessive heat, electric contact or corrosion. Some of the contents are stored in pressures of up to 2500 pounds per square inch. Anything that can create a crack or weakness in the cylinder wall could cause it to rupture and explode: sending sharp metal pieces, like shrapnel, through the work area.
2. Make sure the cylinder has the valve cap on when it’s not in use, especially in transportation. Exposed and unprotected cylinder valve is going to increase the risk of the valve becoming severed.
The Compressed Gas Association (CGA) has established a 0.300- inch maximum valve inlet diameter to minimize the propulsion effect if the valve becomes severed. When a valve gets broken, the cylinder will rapidly release all its gas (which can create a health and or flammability hazard), cause a whistling sound and may spin uncontrollably.
WorkSafe BC regulation stipulates the valve cover must be on the cylinder when it’s not connected for use.
3. Take special care in handling and securing the cylinder. Don’t be afraid to use a cart to move the cylinder about the shop. The most common hazard with cylinders is they fall over or get tipped over.
They are heavy and awkward. They can fall on you or your coworker or … whatever you have within its vicinity … falling on the unintended might lead to the most dangerous consequences.
4. Keep the cylinders in a well-ventilated area. Cylinder valves can leak.
Minimize the Risk of Cylinder Contents
1. Follow the markings on the cylinder. Each compressed cylinder has unique hazards based on the contents.
2. Don’t go by the color of the cylinder. There are no standard colors for gases. Gas suppliers have their own markings; some use one color for all their gases.
3. Flammable gases should be in well-ventilated areas. Flammable gases can burn or explode when certain conditions exist. Flammable gases have an upper and lower flammable limit. When those conditions are met, it can be ignited. E.g. Hydrogen can be ignited when its concentration in the air is between 4 and 75%. Below 4% it is too lean and over 75% it’s too high.
– For Flammable gases to ignite, they require an ignition source: open flames, sparks, and hot surfaces.
– Some flammable gases are heavier than air. In a poor ventilated area, they can settle and collect in low areas. The gas trail can lead far from the cylinder. But if the gas trail connects with an ignition source, the fire produced can go back to the cylinder.
– The normal oxygen content in air is 21%. If air becomes more enriched with oxygen it can cause things to ignite quicker and burn faster.
Fires in atmospheres that are oxygen enriched are hard to extinguish and spread rapidly.
– Inert gases like argon and nitrogen don’t explode or burn but they have the ability to displace air and reduce the oxygen level.
Depending on the level of concentration it can lead to injury or death.
4. Acetylene cylinders should be always kept upright. If they have to be laid down for transportation than WorkSafe BC says it must be placed in the upright position for a minimum of 1 hour.
Acetylene is one of the Dangerously Reactive Gases. Some pure compressed gases are chemically unstable. If exposed to slight temperature or pressure increase, or mechanical shock they can readily undergo certain types of chemical reactions. These reactions can be violent, resulting in fire or explosion. This is why there are inhibitors put in acetylene: to prevent hazardous reactions.
5. Worksafe BC also mandates that a worker must not permit oil or grease to contact an oxygen cylinder valve, regulator or fitting.
6. Worksafe BC says the worker is not to stand in front of the regulator when the cylinder valve is being opened.
As with all risk-reward reviews, there is a reward when all forms of risk have been accounted for. Those gases (that you minimized the risk) have the ability to increase your productivity, make better welds, cut, and weld. It has been gases that have allowed manufacturers to create better welding wires: metal core wires that are fast and that make better welds.