Air Pressure And Plastic Barrels: Understanding Safe Limits

Plastic barrels are used in a variety of applications, from shop air systems to sump pumps. The pressure they can withstand depends on their material, design, and any modifications. Steel drums can generally handle higher pressures than plastic ones, with standard steel drums withstanding up to 5 to 7 psi before requiring a pressure relief valve. However, some sources suggest that plastic drums can withstand higher pressures, with one user reporting a pressure of 30 psi before shutting down the experiment. It's important to note that manufacturers often specify a drum's maximum pressure rating, so it's crucial to refer to those guidelines for safe usage.

The pressure a barrel can withstand depends on its material, design, and modifications

A sealed metal drum can withstand up to 65 psi before the top unrolls and blows the barrel. However, one user reported that they pressurised a plastic drum to 30 psi and it was "flowing pretty good but not 80 ft". Another user suggested that 40 psi might be too much for a plastic drum. Beer is only pressurised to 25-30 psi, and that's only to force carbonate it.

Steel drums can handle higher pressures than plastic ones

In contrast, plastic drums are rated to withstand much lower pressures. For example, beer is only pressurized to 25-30 psi to force carbonate it. A user on Reddit reported that they got a plastic drum up to 30 psi before shutting it down, and another user commented that 40 psi "may be too much" for a plastic drum.

Manufacturers specify a drum's maximum pressure rating

The pressure rating of a drum can be found by looking at the UN rating. For example, the UN rating 1H1/Y1.8/120/09 can be read as follows: the first number after the Y refers to the specific gravity of the material the drum is rated to contain; the second number after the Y refers to the hydrostatic pressure the drum is designed to withstand. In this case, the drum is rated to contain a material with a specific gravity of 1.8 and withstand a hydrostatic pressure of 120 kPa.

It is important to note that the pressure a drum can withstand also depends on its size. For example, a 55-gallon drum will have a different pressure rating than a smaller drum.

When pressurising a plastic drum, it is important to consider the potential risks. For example, one user reported that they were able to get a sealed metal drum up to 65 psi before the top unrolled and blew the barrel about 50 feet, rattling every window in the neighbourhood. Another user reported that they were able to get a plastic drum up to 30 psi before shutting it down, but that it was not able to force the water up 80 feet.

A standard steel drum can withstand 5-7 psi before needing a pressure relief valve

For example, a sealed metal drum can withstand 65 psi before the top unrolls and blows the barrel. Beer is pressurised to 25-30 psi, and 40 psi is considered a lot of pressure.

Beer is pressurised to 25-30 psi

The pressure a barrel can withstand depends on its material, design, and any modifications it may have. Steel drums can handle higher pressures compared to plastic ones. Manufacturers often specify a drum's maximum pressure rating, but as a general rule, standard steel drums can safely withstand pressures up to around 5 to 7 psi before needing a pressure relief valve to release excess pressure.

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