600 PSI Cylinder Travels 1/4 mile

600 PSI Cylinder Travels 1/4 mile

600 PSI Cylinder travels ¼ mile

Don Kinney


Cylinder Training Services creates blogs, posts and holds classes to remind users to use safe procedures when handling all pressurized cylinders.

This specific incident involved two employees moving a 600 psi (41 bar) Halon (fire suppression) cylinder to be weighed. Not knowing the exact specifications of this 4BW cylinder or capacity it is within the range of 48” (1.2m) tall and around 200 lbs (90 kilos).

During movement, the cylinder was dropped, and the valve struck the corner of a concrete ledge. A short fall against the hard surface dislodged the valve. Once the valve broke off, the pressure in the cylinder caused the cylinder to act as a projectile. This incident occurred outside a building.  With no containment, this cylinder travelled approximately ¼ mile or .4km before being stopped by a fence. Luckily nobody was injured.

This example reminds us that even lower pressure cylinders (600 psi / 41 bar) have explosive force. In this instance, nobody was injured. Imagine if the cylinder was in a confined area where the energy could not be dispersed. Think about the rapid escape of a Halon gas in a confined area, and the exposure of the employees.

This specific cylinder was not fitted with a safety collar for a protective cap. It was designed for semi-permanent installation, attached to a wall, and connected to a fire suppression system. Some system designs have a protective collar, which is added at installation.  Any time there is an option to add a safety collar or protective cap, it should be added. For a relatively small fee up front, it may prevent a catastrophic event.

 It does not appear that the workers violated any safety protocols, in fact they were moving the cylinder to weigh it as part of a safety inspection. Not knowing the distance of movement, about the only obvious safety issue was not using a dolly or device to move the cylinder and help prevent it from falling over. But there is no guarantee that a dolly or moving device would have prevented the incident.

We mention this incident for a few reasons. The workers were likely performing a routine function. They might have been focused on the task at hand, weighing the cylinder. They might not have taken the extra steps to remember that they were moving a high-pressure cylinder with compressed gases. Could a safer system of weighing the pressurized cylinder be used? Possibly so by getting the weight of an added dolly and keeping the cylinder secured during movement and weighing.

When dealing with any high-pressure cylinder safety cannot be taken for granted. Any cylinder over 30 psi can harm the user or operator. When we start increasing the pressures to hundreds or thousands of PSI (tens or hundreds of BAR) the hazards get worse. Fill Station Technicians and visual inspectors need to constantly be aware of the hazards when working around cylinders. A simple trip or stumble may cause the cylinder to be launched as a projectile or rupture in a confined space. Be aware of concerns involving all high-pressure cylinders. A simple trip or stumble can create a catastrophic event.

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