Flexitanks are normally made of polyethylene in the available volume of up to 24,000 liters that is fitted inside a standard 20-foot dry box container. Also known as Flexitank or Flexibag, it is a soft, light bladder. These Flexitanks are ideal for the transportation of non-toxic liquid cargoes in bulk and the bladder is generally intended for one-time use.
To assist the chemical companies, their customers, and logistics service providers in being cautious with unsafe situations in the supply chain of Flexitanks, especially best practices for effective unloading, here are a few guidelines that should be taken into account.
Proper loading of the container ensures trouble-free unloading subsequently. Here are the things that need to be kept in account before and while loading to make sure it is done effectively.
Check the suitability of the combination of the Flexibag and container according to the manufacturer’s instructions and the loading limit as per the manufacturer’s specifications.
A visual audit of the container should be carried out to be sure that there are no structural damages in the container. The exterior of the container must be devoid of any ‘dangerous goods’ marking or any other markings from the previous cargoes.
Flexitank suppliers should provide a manual including the process description of the container. A trained and responsible person should be assigned for correct loading and filling of the Flexitank. Lastly, a checklist for all containers and Flexitank checks should be used.
The filling process can start after the flexibag is installed. A few precautions are to be maintained.
Avoid unintended movement by securing the vehicle with wheel chocks. The bulkhead and valve used in the Flexitank should not be in contact with the interior container doors. The hose must be connected and secured to minimize the stress on the valve. Make sure that all the valves are in the correct position before the loading process starts. The container’s left door should be closed properly before the loading starts for additional precaution.
Use spill protection devices like a collecting bag or drip tray. Prevention of gases entering the flexibag during or after filling flexibag is a must. The tightness of the connections of the pump and hoses should be checked after starting the pump. The Flexibag must be filled to its correct capacity and tolerance according to the manufacturers’ instructions. A lower filling rate is recommended to start the filling process. Avoid pumping air in the flexitank.
Once all the protocols are maintained for the perfect loading, it becomes easier to manage the process of unloading without any untoward events.
Best Practices for Unloading
Before going through the recommendations below for the unloading process, the general precautions and guidelines mentioned above for the loading process should be considered during unloading especially during the usage of hose support or the supervision of the unloading process.
- The right-hand door of the CTU should be opened carefully.
- Till the time the Flexitank is adequately empty, keep the door on the left hand closed.
- All the required steps for spill protection should be undertaken.
- Ensure that all markings are removed from the container after the Flexitank has been removed from the container and it is clean and safe.
- Also keep in mind the design of the flexitank, for instance, a multi-layer tank versus single-layer. An outer layer should be selected based on the built of the material so that it provides additional risk mitigation benefits such as:
- Mechanical stability to accommodate the effect of the heating devices. Prevention of the occurrence of localized hot spots and potential loss of integrity due to thinning.
- Resistance to potentially damaging things like welding bars or sharp angles that could puncture the bag if the heating device protection is dysfunctional.
- Be careful while heating the cargo before unloading. The weather conditions during transport or the physical properties of the product may require the application of a heating system to smoothen the unloading process. If there is a need to use heating systems, the method, and devices used for heating the product should be part of the risk assessment. The desired temperature should be kept below the maximum loading temperature specified. Ideally, the desired temperature should be kept below the maximum loading temperature specified by the manufacturer.
- The effectiveness of the heating system to raise the cargo temperature should be taken into account, considering ambient cargo temperature and environmental temperature.
- Only trained and competent personnel should conduct the heating. Also, ensure that the SOP is followed during the installation of the heating system.
- The cargo should be suitable for heating and have a melting point not exceeding the maximum temperature of the Flexitank. The cargo should remain static during heating. The heating should be carried out close to the unloading point.
- Inspect if the Flexitank walls are straight.
- In case the Flexitank is bulging, check if it is due to weak walls or to overpressure. If there is overpressure take the required measures.
- Check that container is not dripping. If dripping, follow the required measures, for instance, placing the flexitank in a spill containment area. Ensure that flexitank is parked on a spill containment area at the unloading station to facilitate the recovery of any leakage. See to it that the drip recovery bucket in place.
- Make sure that the hose is properly connected and secured with support. Check that flexitank is blocked with two chocks in opposite directions. Ensure that during the whole unloading, the left-hand door remains closed.
- See to it that required Personal Protection Equipment (PPE) is used.
- If the Flexitank is tilted during the unloading, with the help of a tilting trailer chassis, check that the trailer is well secured.
- Ensure that Flexitank is grounded if required.
- Inspect that the seal number on the valve with valve seal number on transport documents.
- See to it that the temperature of the product is compatible with the unloading equipment if there are any needs for temperature/viscosity products. If yes, take the appropriate measures like placing the flexitank in a headed shed.
- In cases where heater pads are used, inspect the pressure ratings. Also, check the site Health and Safety requirements where heater pads are used are met.
- Ensure that there is no drip during the unloading on the connections.
- Make sure that the hose support remains correctly positioned to avoid any constraints on the valve.
- Go through the check-list at the unloading station after unloading and disconnecting.
- Ensure that the bag is effectively empty. Make sure that the bag with the remainder of products and the equipment of flexitank is correctly recovered and stored according to the applicable recycling procedure. Follow the application procedure to empty the bag.
- See to it that the Health Safety and Environmental requirements are met for tanks that require manipulation (rolling/folding) to facilitate a clean discharge and to minimize residue levels.
Following these best practices by the book can ensure that your unloading process is smooth and free of any unforeseen glitches. An end to end procedure of effective loading and unloading is highly recommended to make it hassle-free transportation and unloading.
We at Fluid Flexitanks are a leading Flexitank Manufacturer in India, delivering products with global standards of quality. Our Flexitanks are FDA approved, made of virgin polyethylene and polypropylene, suitable for a wide range of food-grade and non-hazardous liquid cargos. Please contact our team for more details on our offerings.