Yes, you can heat products inside a flexitank during transport and storage. Flexitanks are designed to accommodate temperature-sensitive bulk liquids, and heating is applied primarily at the point of discharge to restore viscosity and ensure smooth unloading. For cargo that solidifies or thickens at ambient temperatures, proper heating planning is essential for a successful shipment.
Flexitanks can hold up to 27,000 litres of bulk liquid cargo, making temperature management a practical concern for a wide range of industries. The sections below cover the heating methods available, how discharge heating works in practice, which products typically require it, and how to plan your shipment accordingly.
Can you heat products inside a flexitank?
Yes, heating products inside a flexitank is possible, but it is important to understand that flexitanks themselves are not equipped with built-in heating systems. Heating is applied externally, either to the container unit surrounding the flexitank or directly to the cargo during the discharge process. This makes advance planning and clear communication with your logistics provider critical.
Unlike ISO tank containers, which can be fitted with heating coils or steam jackets as part of the tank structure, a flexitank is a flexible bladder installed inside a standard 20-foot shipping container. This means any temperature management relies on external methods. That said, many bulk liquid cargoes transported in flexitanks do require some level of heat treatment, and experienced flexitank logistics providers have well-established procedures to handle these needs safely and efficiently.
What heating methods are used for flexitank cargo?
The most common heating methods for flexitank cargo are steam heating applied to the exterior of the container, electric heating blankets wrapped around the container, and heated storage facilities used during transit stops or at the destination. The right method depends on the cargo type, required temperature, and available infrastructure at the destination terminal or warehouse.
Steam heating is widely used at industrial facilities and ports where steam lines are readily available. Electric heating blankets offer a more flexible solution when steam is not accessible, and they can be applied directly to the container walls. In some cases, cargo is heated in a temperature-controlled warehouse before or during discharge rather than while still inside the container. Each method has its practical advantages depending on the destination country, terminal capabilities, and the sensitivity of the product being transported.
How does heating during discharge work for flexitanks?
Heating during flexitank discharge works by warming the cargo sufficiently to reduce its viscosity before and during the pumping or gravity-flow unloading process. The container is typically placed in a heated environment or wrapped with heating equipment, and the cargo is allowed time to reach the target temperature before the discharge valve is opened.
The discharge process itself relies on gravity flow or a pump connected to the flexitank’s outlet fitting. When a product has thickened or partially solidified during transport, attempting to discharge without heating can damage the flexitank, block the outlet, or result in incomplete unloading. Allowing adequate time for the cargo to heat through the full volume of the flexitank is essential, as the thermal mass of up to 27,000 litres of liquid means heating is not instantaneous. Coordination between the receiving facility and the logistics provider ensures the right equipment is in place before the container arrives.
What products typically require heating in a flexitank?
Products that typically require heating in a flexitank are those with a high pour point or melting point, meaning they solidify, gel, or become too viscous to pump at ambient temperatures. Common examples include vegetable oils, animal fats, molasses, glycerine, biodiesel, and certain industrial oils or resins.
Food-grade products such as palm oil, coconut oil, and tallow are among the most frequently transported heated flexitank cargoes because they solidify at relatively mild temperatures. Industrial products like lubricating oils, fatty acids, and some chemical intermediates also fall into this category. The specific temperature at which a product begins to thicken varies widely, so it is important to review the technical data sheet for your cargo before booking and to communicate those requirements clearly as part of your international shipping solution.
What temperature limits apply when heating a flexitank?
Flexitanks have a maximum recommended cargo temperature at the time of filling, which is typically around 40 to 50 degrees Celsius depending on the manufacturer and product specifications. Exceeding these temperature limits can compromise the structural integrity of the flexitank liner and create safety risks during transport.
It is equally important to note that flexitanks are designed for non-hazardous cargo only. High-temperature or reactive products that require sustained elevated temperatures throughout the voyage are generally better suited to ISO tank containers, which are built with robust steel construction and can be equipped with proper heating and insulation systems. For borderline cases, always consult with your logistics provider before committing to a flexitank solution. We work closely with customers to assess cargo suitability and recommend the right transport format based on the product’s thermal behaviour and safety profile.
How should heating requirements be planned before booking a flexitank shipment?
Heating requirements for a flexitank shipment should be identified and communicated at the booking stage, before the container is fitted or the transport schedule is confirmed. Key information to provide includes the cargo’s pour point or solidification temperature, the required discharge temperature, and the available heating infrastructure at the destination.
Effective planning involves several practical steps:
- Review the cargo’s technical data sheet to identify its pour point, flash point, and any temperature-related handling requirements.
- Confirm destination capabilities by checking whether the receiving terminal or warehouse has steam lines, heating blankets, or heated storage available.
- Allow sufficient heating time at the destination, as large volumes of viscous liquid can take many hours to reach the target discharge temperature.
- Communicate with your logistics provider early so that the correct flexitank product is selected and any special handling instructions are documented in the shipping paperwork.
- Consider transit conditions, particularly for long-distance or multi-modal routes where the cargo may be exposed to low ambient temperatures for extended periods.
As a provider of flexitank logistics services in Finland and across the Nordics and Baltics, we support customers through every stage of this planning process, from cargo assessment to discharge coordination. Getting the temperature management right from the start protects both the product and the equipment, and it is one of the details that separates a smooth international freight shipping experience from a costly one. Contact us to discuss your cargo’s specific heating requirements and how we can support your shipment.
