Safety in gas welding, cutting and similar processes

25

Nov

PRAKSHI RAWAT

A fire was put out in the mast house of a cargo ship, where oxygen and acetylene cylinders were housed. For gas welding on the windlass drum, the crew had set up two gas torches in tandem. By temporarily attaching "standard" t-joints at the regulator valves, both torches were linked in parallel from the very same pair of gas cylinders. It was agreed at some point during the gas welding to employ one gas torch to perform out brazing restoration work but at the other torch even when it was linked to the compressed air hoses.

The torch's frictional heating caused a flashback that traveled all the way the hoses to the mast housing, rupturing the pipes at the regulator valve connections and creating a fire. Fortunately, the regulators' backfire, composed of various things, prevented a huge cylinder explosion. If sufficient measures are not taken when conducting gas welding/cutting on board ships, such hazardous mishaps may occur on any ship.

In the engine room but on the deck of a ship, compressed gas cylinders are employed for a range of repair and production operations. For with this function, oxygen and acetylene gas cylinders are by far the most commonly used. Acetylene plants should be built in a safer place.

The following practical advice should indeed be followed when performing gas welding or cutting operations for efficiency and safety, and to also avoid accidents while conducting deck activities:

Retain a vertical position:

Compressed gas cylinders must be handled with utmost caution and kept upright at any and all times, whether filled or empty. Separate and clearly label full and empty cylinders.

Store in Right Spaces:

When appropriate, avoid placing the oxygen and acetylene cylinders together in the same location. Separate them and keep them in well-ventilated areas. When not in use, make absolutely sure their caps have always been on.

Keep Grease and Oil Out:

Oil and grease should be kept out of control valves and fittings. Never use oily or greasy hands to operate cylinder valves and parts.

Ensure Flame Arresters Are Installed Properly:

In the acetylene and oxygen cylinder lines, make very sure non-return valves and flame arresters are installed. One flame arrester is normally attached near the cylinder on the bottom side of the regulator, and then the other near the fire.

Keep the oxygen pressure higher:

When gas welding, make absolutely sure the oxygen pressure is always significantly larger than just the acetylene pressure to avoid acetylene flowing back into the oxygen line.

Handle Acetylene With Caution:

Acetylene will not be used for welding at pressures greater than 1 bar of atmospheric gauge even though it is prone to exploding though in the absence of air.

Rectify the Backfire Cause:

In the instance of a backfire, the oxygen valve should be closed first, followed by the acetylene valve. No actions are to be conducted until the source of the backfire has already been identified.

Handle Flashback with Care:

In the event of such a gas pipe explosion or flashback, the first step should have been to disconnect the cylinder valves for both cylinders. Further action would be taken in accordance with the ship's fire-fighting procedures.

Ensure Proper Connections:

To comply with the Regulatory Standard, the connections here between hose and the blowpipe, including between hoses, should be necessary measures with fittings.

Keep a Consistent Watch:

The temperature of the acetylene cylinder should indeed be a subsequently measured basis. If the temperature rises, the incident should be addressed as though it was a flashback or even an explosion.

Handle Flashback with Care:

In the event of a gas pipe explosion or flashback, the first step ought to be to disconnect the cylinder valves for both cylinders. Further measures shall be taken in accordance with ship's fire-fighting procedures.

Ensure Proper Connections:

To comply with the Regulatory Standard, the connections between both the hose and the blowpipe, including between hoses, should be problems that can be fixed with fittings.

Keep a Consistent Watch:

The temperature of the acetylene cylinder should indeed be measured over time basis. Acetylene plant should be made in a safer place. If the temperature goes up, the incident should be handled as though it were a flashback or perhaps an explosion.

Avoid Hose Interchange:

Manifold hose connections, including outlet and inlet connections, ought not to be changeable between fuel gas and oxygen manifolds and heads.

Replace any old or faulty hoses:

Any hose that really has undergone flashback must be replaced by the new one.

Hoses Should Be Handled Properly:

Hoses should indeed be set out properly and kept away from turning machinery, sharp corners, and high-temperature locations while completing the tasks. Make certain they are really not dangling, knitted, or tipped over.

Use Only Approved leak detection fluid:

It should be used to identify a leak from a hose or regulator configuration. Non-detergent soap (Ivory) can be replaced if this is not obtainable.

Never Use Sealing Tape:

To prevent leaks between metal to metal gas tight junctions, never use sealing tape composed of metal combining material. With an oxygen cylinder, it might allow a metal-oxygen fire to start.

Never Over Tighten Connections:

To stop a leak, never overtighten any nut here on regulator connections or the cylinder valve spindles. This will have the potential to cause injury.

Take the Following Maintenance Steps:

Cleaning any obstruction in the blow pipe must only be done with sophisticated equipment. The existing network must be isolated before any repairs can be conducted. Never try to fix pressurized oxy-acetylene equipment or conduct any unauthorized access to sensitive work equipment.

Only use safe ignitors:

Only a friction ignitor or any other reliable flame source will be used to light a blowpipe. Avoid and use a lighter as a sudden flame; alternatively, the blow pipe may contact the lighter's body that causes it to explode.

Never Use Oxygen:

Never use oxygen for Ventilation, Cooling, or Blowing Dust off Interfaces or Clothes: Oxygen shouldn't be used for ventilation, cooling, or blowing dust off surfaces or clothes.

Hoses with flashback should be discarded:

Any length of hose that really has experienced a flashback should indeed be discarded immediately.

Last but not least, double what is the workover checklist and risk evaluation forms have been properly completed before commencing any type of gas welding. Also, remember to implement all safety rules when conducting such tasks in restricted areas.

The ship and its crew are at risk from greater gas cylinders containing extremely flammable substances. Handling such gear requires extra caution and concentration, along with attention to all safety precautions and product's instructions.