Tech Talk – Why it’s important not to cause a vacuum

The act of emptying 1000L of liquid out of an IBC is fairly straight forward right? All you need to do is open the valve at the bottom of the tank and then leave the IBC to drain until it’s empty.

Well, not quite. Depending on the liquid, emptying an IBC can actually lead to some big issues, the main one being that you cause a vacuum to form within the bottle. Mostly occurring on faster flowing liquids, a vacuum within an IBC bottle can lead to some scary results – the main one being that the IBC actually implodes in on itself – here’s an example (albeit an extreme example) of what an implosion can look like on something much larger and heavier. Scary stuff right?

The reason this happens is because as the liquid drains out of the bottom of the tank, there is no where that air can get back into the tank and replace the space left where the liquid was, thus forming an area within the tank where there is no air at all

Thankfully there are two very easy and simple ways around this issue. The first is simply to open the top cap and allow air in through the manhole opening. But what if your chemical or liquid is harmful or has lots of nasty vapours? Well Pensteel can also offer an anti-vacuum vent which will allow air into the IBC as it drains, again allowing the air to fill the gap left by the liquid.