Enhancing the safety of disused LP cylinders

LP gas marketer, Elgas goes to great lengths to protect the safety of its domestic and commercial customers. As part of its safety program, its hundreds of thousands of cylinders are individually assessed for ongoing structural integrity and lifespan every time they are filled.

Disposal of defective or doubtful cylinders is itself a major undertaking, given the multitude of steel and aluminium cylinders Elgas has in capacities from 5-90 kg, used in diverse markets ranging from barbecues, caravans and households through to factories and commercial sites.

Efficient destruction of defective cylinders is a challenge, because the tough cylinders are manufactured with high safety margins built in, being designed to withstand rugged environments and extensive manual handling. Thousands of cylinders are destroyed every year, because Elgas takes no chances with its safety record and this is increasingly important with the recent significant expansion into the leisure market via its acquisition of Swap N Go.

"When we find cylinders that are corroded or have been dropped, damaged or deformed - we don't hesitate. They are scrapped," says Elgas' Asset Manager Lee Duncum, who is responsible for a series of Enerpac hydraulic presses being introduced around the country to make the job of scrapping the cylinders safer and swifter.

The hydraulic power of the compact high-pressure cylinders (700 bar, 10,000 psi) is used to punch a hole in cylinders marked for destruction, quickly and safely rendering them useless for any function except scrap.

Enerpac's H-frame presses feature a Hydra-Lift bed, which reduces the manipulation required to position work pieces. This roller head design allows movement and locking of the press head from side to side, further facilitating work piece set-up and increasing safety by reducing handling.

Elgas drew on its long association with Enerpac to develop a better solution to its expanding disposal task, which includes cylinders used in the highly successful Swap N Go cylinder program. The resulting Enerpac punch program is now being expanded to encompass mobile presses and fixed vertical presses for the largest industrial types.

"The main need for the presses was due to the 9 kg bottle because there are so many out there," said Duncum, adding that - in addition to routine visual checks - each cylinder has a 10 year test date.

"Anything found in the way of deformities or corrosion, they are scrapped. Deformities can come about through the bottles being dropped or occasional misuse, such as when people weld them to caravans, for example.

"We have had people who suddenly decide the caravan might lose a bottle - so they become engineers and weld them to the brackets. That's pretty scary, because the moment the cylinder's integrity is changed - as when welded - it becomes a major problem. We have to say they aren't safe."

Elgas asked Enerpac to modify its fixed hydraulic cylinder destruction units to accommodate a 240 V flameproof electric motor, so the unit pumps and cylinders could be operated inside areas that could otherwise be potentially hazardous.

"In the trailers, the Enerpac units are driven by air from a compressor, because they are not required for working in hazardous areas - more for punching old stock in the field and getting rid of them. They are virtually self-contained compressors, sitting in the trailer, and driving the air motor that does the hydraulics," says Duncum.

They roll it into the press and clamp it. They operate the press to punch the cylinder horizontally, so there is no lifting at all with the unit. It's not really a viable proposition for a trailer unit, travelling around the country, but with a fixed installation predominantly for 18 and 45 kg cylinders, the arrangement is a great advantage."