Checklist for buyers of second-hand IBC containers: what do you need to find out before installing the container on its rack?

Checklist for used IBC containers helps to distinguish a serviceable cylinder from one that may leak, contaminate new liquid or fail during mobile use. A sound appearance alone is not enough, as chemical stress on the inner liner, valve wear and damage to the base may not be apparent at first glance. It is advisable to carry out an inspection before lifting the container onto the rack and filling it.

Find out what the container previously held and its usage history

Ask the seller for information about the tank’s previous contents, intended use and cleaning. The labels, hazard warnings and product names on the tank must match the seller’s description. If the history remains unclear, do not use the container for watering, as drinking water for animals, in connection with foodstuffs, or for washing water that may come into contact with sensitive surfaces.

Residues from previous chemicals may be absorbed into the polyethylene of the inner bottle or remain in the valve, cap and seal components. An odour, discolouration or greasy film indicates a need for cleaning, but the absence of an odour does not prove that the container is clean. Check the safety data sheet to ensure that the previous substance is compatible with the intended liquid. Finnish Safety and Chemicals Agency (Tukes) provides information on the safe handling of chemicals.

Checklist for the inner container of a used IBC container

Inspect the inner bottle whilst it is empty, in good lighting. Examine all sides, the top and, in particular, the bottom corners, which are subject to stress caused by impacts and the movement of the liquid. Look for hairline cracks, dents, bulges, deep scratches and areas where the plastic has turned pale. Pale stress marks may indicate that the plastic has stretched.

Also look inside the container through the filling hole. Use a torch, but do not go inside the container. Any sediment visible at the bottom, stubborn colour stains or a layer adhering to the walls may prevent the container from being reused. If liquid fertiliser or a preservative is to be added to the tank, check with the supplier of the substance to ensure that the materials of the inner liner, seals and valve are compatible.

In the water test, the tank is filled with clean water in a controlled environment. Start with a small amount and check the bottom corners, seams, cap and valve. A full tank must not be subjected to a test load whilst resting on a damaged pallet. If the intended use changes, please also refer to Instructions for cleaning and rinsing an IBC container.

Washing removes residues, but it does not repair brittle plastic, a damaged base or an unknown history of use.

Protective cage and base structure in mobile use

The protective cage supports the inner bottle and transfers the load to the base structure. Check the welds, pipe joints and any signs of rust damage. A broken weld, a bent vertical support or a cage that has bulged outwards weakens the structure as a whole. Sharp edges can rub the inner cylinder raw due to vibration, even if the tank remains stationary in storage.

The base pallet must be inspected from underneath. Plastic pallets must not have any cracks at the lifting channels or corners. Steel pallets must be checked for areas thinned by rust, loose joints and warping. In wooden pallets, moisture damage, cracks or loose fixings may cause a full container to shift on the rack or the base to break during lifting.

Checklist for the valve on a used IBC container

The valve is one of the most common points of leakage in a tank. Check that the valve body is straight, that the operating lever moves freely, and inspect the protective cap and the threaded connection. The lever must move smoothly and close fully into its set position. A loose lever, a stiff mechanism or a misaligned valve body may indicate an impact, chemical damage or a worn seal.

Inspect the connection between the valve and the inner container. There must be no signs of dried-up spillage, discolouration or deformation of the plastic at the connection point. Also check the type of valve and the connector size, as IBC containers that look similar on the outside may use different thread types. An incorrect fit may damage the valve and cause it to leak when subjected to vibration.

Carry out a leak test using water, both with the valve closed and with the hose connected. Wipe the connection dry before the test so that even the slightest seepage is visible. At the same time, check the cap seal and the condition of the top cover. Replacing the valve may be justified if the rest of the tank is intact and a new valve is guaranteed to fit the outlet on the inner cylinder.

Test run before installation on the rack

Carry out the final test on a level, stable surface. Add water in stages and check the shape of the tank, its base and the valve. The inner bottle must not protrude unevenly through the openings in the cage. Stop filling the tank if the base sinks, the cage moves or water leaks from any part of it. Do not attempt to repair a loaded tank.

Calculate the total mass of the complete assembly before installation. Water weighs approximately one kilogram per litre, so 1,000 litres of liquid will add around 1,000 kilograms to the load, in addition to the mass of the tank and the frame. The density of the liquid may be greater than that of water. More detailed examples can be found A guide to the weight and loading of IBC containers.

It is advisable to keep the checklist for used IBC containers with the equipment inspection records. Mark the container with an identification number and record its permitted contents, the date of inspection and any repairs carried out. Take any container you are unsure about out of service. The cost of a new container is negligible compared to the damage caused by leaks, breakages or the use of the wrong liquid.