Views: 0 Author: Site Editor Publish Time: 2026-08-24 Origin: Site
Flexitank safety is a systemic issue, not a single product attribute—it depends on the synergy of container condition, cargo compatibility, installation, loading/unloading operations, and the manufacturer’s quality control.
The Container Owners Association (COA) Code of Practice (TG‑07) and PAS 1008:2018 together define industry standards for safe flexitank operations.
Container condition is as important as flexitank quality—a damaged or unsuitable container creates risks even if the flexitank itself is properly manufactured.
Industry experience shows that valve‑to‑door impacts account for a significant proportion of flexitank leakage incidents, but improper installation and inadequate container preparation are equally critical risk factors—highlighting the need for strict adherence to installation and preparation protocols.
A reliable flexitank manufacturer should provide test documentation, installation guidance, container selection requirements, and technical support—not just sell a product.
Yes, professionally manufactured and correctly installed flexitanks can be a reliable solution for transporting suitable non‑hazardous bulk liquids. This is in line with the framework established by the Container Owners Association (COA) Code of Practice for Flexitank Container Systems (TG‑07) and PAS 1008:2018, which together define the performance, testing and quality management requirements for safe flexitank operations.
However, the safety of a flexitank does not depend on the bag alone. A safe flexitank operation is a complete system involving:
Flexitank design
Material compatibility
Container condition
Installation
Loading procedures
Cargo temperature
Fill volume
Valve configuration
Transport conditions
Unloading procedures
Quality control by both manufacturer and operator
This is why companies looking for a reliable flexitank manufacturer should not evaluate suppliers on product price alone. The COA has developed the Code of Practice for Flexitank Container Systems (TG‑07), covering manufacturing, testing, installation, operations, training and quality management. Manufacturers and operators that comply with TG‑07 can obtain COA Quality Conformity Certification (CQC) and be listed on the Flexitank Quality List (FQL). PAS 1008:2018 specifies the performance and testing requirements for single‑use flexitanks used in the intermodal transport of suitable liquid commodities in general‑purpose freight containers.
The key principle is simple: flexitank safety is a system, not a single product feature.
A professionally designed flexitank should be engineered around the cargo characteristics and the conditions it will encounter during transport. Important safety factors include:
The flexitank film must be suitable for the liquid being transported. Different liquids have different:
Chemical properties
Viscosity
Density
Temperature requirements
Interactions with packaging materials
A flexitank manufacturer may need to evaluate cargo compatibility before recommending a specific design. PAS 1008:2018 states that compatibility between the cargo and the flexitank film must be assessed, because suitability depends on the chemical and physical properties of both the liquid and the film.
The flexitank must withstand the physical forces of:
Filling
Handling
Road transport
Rail transport
Sea transport
Loading and unloading
The filling/discharge valves are critical components. Valve connections must maintain integrity during:
Filling
Transport
Discharge
The COA technical guide includes routine testing of filling/discharge valves as part of flexitank quality management.
Flexitanks are installed inside freight containers. Therefore, the condition of that container directly affects the safety of the entire system. Even a properly manufactured flexitank can be at risk in a damaged container.
A professional flexitank manufacturer should operate a documented quality management system covering material testing, production control, finished product inspection and traceability.
Properly selected, installed and loaded flexitanks are compatible with suitable freight containers. However, container bulging or deformation can still occur if the container, flexitank, loading conditions or installation process are not appropriate. Potential risk factors include:
Overloading
Incorrect fill volume
Unsuitable container condition
Improper installation
Damaged container walls or floor
Sharp edges or protrusions
Incorrect restraint systems
Improper door operation
Ocean Blue Whale’s container selection guidelines specifically recommend inspecting containers for structural issues, sharp edges, dents, rust, loose parts, floor defects, contamination and other conditions that could damage the flexitank. Therefore, container inspection should be regarded as an essential part of flexitank safety, not an optional step.
Not every freight container is suitable for flexitank installation. Before installation, the container should be checked for:
The container must be structurally sound and suitable for the intended transport service.
The interior should be:
Clean
Dry
Free from sharp objects
Free from protruding nails or screws
Free from significant dents
Free from loose floor components
Free from residues that could contaminate the cargo
Any sharp edges, damaged surfaces, protrusions or defects that could puncture, abrade or damage the flexitank should be removed or properly protected.
Doors must close correctly and must not interfere with the flexitank or its restraint system.
The container should have valid identification and safety markings for the intended transport service.
Ocean Blue Whale’s container guidelines emphasise that containers with questionable structural integrity or unsuitable installation conditions should be repaired or replaced rather than used.
Correct installation is one of the most important factors in preventing flexitank damage. The installation process varies depending on the flexitank design, container, valve configuration and manufacturer’s instructions. A typical installation includes:
Confirm that the container meets the manufacturer’s requirements.
Remove:
Debris
Sharp objects
Loose hardware
Contaminants
Residues
Protect any areas that may contact and damage the flexitank.
Correctly position the flexitank inside the container according to the manufacturer’s installation instructions.
Properly install any required bulkheads, protective materials or other restraint components.
Before loading, confirm that valves and connection systems are correctly positioned and secured.
Carry out an inspection of the installation before liquid loading begins.
Ocean Blue Whale’s installation guides emphasise container preparation, removal or protection of sharp edges, correct positioning, pre‑loading inspection and adherence to the manufacturer’s installation instructions.
Loading is another critical phase. Before loading, operators should confirm:
Cargo is compatible with the flexitank
Flexitank is correctly installed
Container is suitable
Valves and connections are secured
Loading equipment is compatible
Planned fill volume is within product specifications
Cargo temperature is within the manufacturer’s specified range
A flexitank should never be filled beyond its rated capacity. The correct fill volume depends on:
Flexitank rated capacity
Liquid density
Cargo temperature
Container limitations
Transport requirements
Manufacturer’s instructions
Different models of flexitanks may have different loading requirements. Therefore, buyers should use the manufacturer’s technical data rather than applying a generic fill percentage to every flexitank.
Ocean Blue Whale’s installation guidelines recommend a maximum fill level of 100% ± 3% (i.e., 97%–103%) for applicable flexitanks, with emphasis on controlling loading and post‑fill inspections.
Yes. Temperature affects:
Liquid expansion
Liquid viscosity
Film performance
Internal pressure
Loading and discharge behaviour
Therefore, cargo temperature should be considered before loading. A flexitank designed for one temperature range may not be suitable for a different application. For example:
Standard food liquids are loaded at relatively moderate temperatures
High‑viscosity liquids may require heating during discharge
High‑temperature cargoes require specially designed flexitank systems
Appropriate temperature ranges should always be based on the specific flexitank manufacturer’s technical specifications. Do not assume that every flexitank can carry hot liquids.
Flexitanks are commonly used to transport suitable non‑hazardous bulk liquids. Typical applications include:
Edible oils
Palm oil
Vegetable oils
Rapeseed oil
Wine
Fruit juice concentrates
Syrups
Food ingredients
Lubricating oils
Base oils
Industrial oils
Latex
Resins
Glycerine
Some non‑hazardous chemicals may also be transported in flexitanks, subject to material compatibility and applicable transport requirements.
Ocean Blue Whale’s product literature lists food products, lubricating oils, latex, plasticisers, surfactants, base oils, glycerine, industrial oils and other liquid products as applications for its flexitank solutions.
Standard flexitanks should not be assumed to be suitable for dangerous goods. PAS 1008:2018 covers single‑use flexitanks used for the intermodal transport of liquid commodities that are not classified or regulated as dangerous goods. Whether a specific liquid can legally and safely be transported in a flexitank depends on:
Cargo classification
Applicable dangerous goods regulations
Flexitank design
Material compatibility
Shipping line requirements
Container requirements
Route requirements
Manufacturer’s approval
Therefore, companies transporting potentially regulated goods should obtain a technical compatibility assessment and regulatory confirmation before selecting a flexitank. Do not use a standard flexitank for dangerous goods simply because the liquid physically fits inside.
When evaluating quality flexitank manufacturers, buyers should go beyond marketing claims and request relevant documentation. Important standards and quality references include:
COA TG‑07 covers flexitank system requirements and quality management. Areas covered by the COA framework include:
Manufacturer quality management
Installation and operating instructions
Material testing
Valve testing
Rail impact testing
Factory site audits
Manufacturers complying with TG‑07 can obtain COA Quality Conformity Certification (CQC) and be listed on the Flexitank Quality List (FQL). CQC is required for each manufacturer, each flexitank design and model, and each manufacturing facility.
PAS 1008:2018 specifies performance and testing requirements for single‑use flexitanks used in general‑purpose freight containers for suitable liquid commodities, covering:
Flexitank film material properties
Valve leak‑tightness
Rail impact testing
Flexitank information requirements
For food‑grade flexitanks, buyers may need to verify compliance with applicable food contact regulations, for example:
FDA requirements for the US market
EU food contact requirements
FSSC 22000
Other customer or destination market requirements
The specific certifications required depend on the cargo and destination market.
A professional flexitank manufacturer should have a documented quality control system. Depending on the product and applicable standards, tests may include:
Film properties
Thickness
Mechanical properties
Material identification
Heat seal strength
Seam integrity
Heat seal consistency
Valve integrity
Leak‑tightness
Functional performance
Leak testing
Visual inspection
Dimensional inspection
Packaging inspection
The COA technical guide specifically requires material and valve testing in accordance with PAS 1008:2018, with test records retained for audit. For example, Ocean Blue Whale flexitanks have successfully passed CRCC rail impact testing and AAR (Association of American Railroads) rail impact testing, demonstrating their durability in rail transport applications. Ocean Blue Whale fully complies with the COA Flexitank Code of Practice and has participated in the revision of COA industry standards.
Leakage is one of the risks buyers most want to understand. Leakage can result from a combination of factors rather than a single manufacturing defect. Industry experience indicates that valve‑to‑door impacts, improper installation and inadequate container preparation are the most significant risk factors for flexitank leakage. Potential causes include:
Damaged container surfaces
Sharp objects inside the container
Improper installation
Improper loading
Overloading
Valve or connection problems
Cargo incompatibility
Improper handling
Damage during transport
Ocean Blue Whale’s container selection guidelines list sharp edges, tools, metal parts, damaged container surfaces and unsuitable container conditions as potential causes of flexitank damage and leakage. This is why simply asking a manufacturer for their “damage rate” does not tell the whole story. A more valuable procurement question is:
What quality control, installation procedures, testing standards and technical support does the manufacturer provide to reduce operational risks?
If a leak or abnormal behaviour is detected, operators should prioritise safety and follow the manufacturer’s emergency procedures. General principles include:
Stop the relevant loading/unloading operations if safe to do so
Keep personnel away from any spilled liquid until the cargo type is confirmed and appropriate precautions are known
Follow the cargo’s safety data sheet and on‑site emergency procedures
Prevent unauthorised personnel from entering the affected area
Contact the flexitank supplier or technical support team
Follow the manufacturer’s instructions for containment, transfer or disposal
Appropriate responses depend heavily on the liquid being transported. For food‑grade liquids, concerns may include product contamination and clean‑up. For industrial liquids, additional chemical, environmental or occupational hazards may be involved. Never assume that the leak response for all cargoes is the same.
Container bulging risk can be reduced by controlling the complete flexitank system. Key measures include:
Selecting a suitable container
Inspecting the container condition
Using the correct flexitank capacity
Loading within specified limits
Correctly installing restraint systems
Following loading instructions
Avoiding unsuitable cargo temperatures
Ensuring container doors can close properly
Ocean Blue Whale’s container condition guidelines emphasise suitable container condition, loading limits, protection against internal defects and proper door operation. Importantly, container bulging should not be automatically attributed to the flexitank itself; the entire container‑flexitank‑cargo system should be evaluated.
Safe unloading requires the same level of attention as loading. Before discharge:
Confirm that the cargo and discharge equipment are compatible
Check valve and hose connections
Ensure the discharge area is properly prepared
Follow the manufacturer’s discharge procedures
Monitor the unloading process
High‑viscosity liquids may require additional discharge equipment or temperature management. For example, Ocean Blue Whale’s product literature describes customised discharge solutions for certain high‑viscosity liquids, including heating systems and specialised valves. The exact unloading procedure should always be based on the flexitank model and cargo characteristics.
Flexitank installation is usually a structured process, but it should be carried out according to the manufacturer’s instructions and by personnel familiar with the equipment. The level of complexity depends on:
Flexitank design
Valve configuration
Container type
Restraint system
Cargo application
Local operating conditions
Ocean Blue Whale provides installation guides for its flexitank systems, covering container preparation, installation, loading and inspection procedures. For large‑scale operations, companies should establish standardised installation procedures and train relevant warehouse or logistics personnel.
When comparing flexitank manufacturers, buyers should evaluate at least seven aspects:
Does the supplier own its own flexitank factory?
Does the company have documented inspection and testing procedures?
Can the manufacturer provide evidence of relevant COA, PAS 1008, ISO, food contact or transport requirements? Does the manufacturer hold COA Quality Conformity Certification (CQC) and appear on the Flexitank Quality List (FQL)?
Can the supplier assess whether the flexitank material is suitable for your liquid?
Does the manufacturer provide installation instructions and technical support?
Can the supplier support customers at different ports and transport locations?
Can the supplier provide product specifications, test records, installation instructions and other relevant documentation?
These factors offer a more meaningful way to identify reliable flexitank suppliers than simply comparing prices.
Ocean Blue Whale is a professional Chinese flexitank manufacturer offering food‑grade and industrial‑grade bulk liquid transport solutions. According to its published technical information, its safety and quality control approach includes:
Raw material and component testing
Cargo compatibility assessment
Production process quality control
Finished product inspection
Material and valve testing
Testing and production procedures based on PAS 1008:2018
COA impact testing for applicable systems
Rail impact testing for applicable rail products, including CRCC rail impact testing and AAR rail impact testing
Ocean Blue Whale has obtained COA Quality Conformity Certification (CQC) and is listed on the COA Flexitank Quality List (FQL). The company has also participated in the revision of COA industry standards and led the update of CRCC rail transport standards. Ocean Blue Whale also publishes container selection and installation guidelines for its flexitank system users.
This approach reflects an important principle in flexitank transport: product quality, container condition, installation, loading and cargo compatibility must work together to achieve reliable transport performance.
Core answer: Professionally manufactured flexitanks are safe when used with the correct product, container, installation and loading procedures.
Detailed explanation: Professionally manufactured flexitanks can be a reliable solution for transporting suitable non‑hazardous bulk liquids when the correct product, container, installation method, loading procedures and transport conditions are used. Safety depends on the complete flexitank system—including material compatibility, container condition, installation quality, loading procedures and cargo temperature—rather than the bag alone. This system‑based approach is consistent with the COA Code of Practice for Flexitank Container Systems (TG‑07).
Core answer: Flexitanks are durable when professionally manufactured and installed, but they can be damaged by sharp objects, unsuitable container conditions, improper installation, improper handling or unsuitable loading conditions.
Detailed explanation: Flexitanks are flexible packaging and can be damaged by sharp objects, unsuitable container conditions, improper installation, improper handling or unsuitable loading conditions. This is why container inspection and correct installation are essential.
Core answer: There is no single universal damage rate that applies to every flexitank manufacturer, cargo, route or operating condition.
Detailed explanation: Meaningful comparisons should consider:
Product design
Container condition
Installation procedures
Cargo type
Loading operations
Transport route
Quality management system
Buyers should request manufacturer‑specific quality and incident data where appropriate, rather than relying on generic industry percentages.
Core answer: Correctly selected and installed flexitanks should not damage standard freight containers.
Detailed explanation: Container deformation risk increases when the container is unsuitable, damaged, overloaded, or when installation requirements are not followed. Bulging risk is often associated with missing door crossbars, overloading or improper installation.
Core answer: Maximum capacity depends on the specific flexitank design and applicable transport requirements.
Detailed explanation: Flexitank capacities vary by container size and model. Typical ranges for 20‑foot containers are 14,000 to 26,000 litres, and for 40‑foot containers 8,000 to 28,000 litres. Buyers should always refer to the manufacturer’s product specifications for the actual rated capacity of each model.
Core answer: Temperature limits vary by flexitank design and cargo.
Detailed explanation: Loading temperatures should always be kept within the manufacturer’s specified range. High‑temperature cargoes may require specially designed flexitank systems.
Core answer: Standard flexitanks should not be assumed to be suitable for dangerous goods.
Detailed explanation: PAS 1008:2018 covers suitable non‑hazardous liquid commodities within its defined scope. Dangerous goods transport requires separate assessment of cargo classification, regulations, equipment, route and approvals.
Core answer: Flexitanks are commonly used for suitable non‑hazardous liquids such as edible oils, wine, fruit juice concentrates, syrups, lubricating oils, base oils, latex, glycerine and other compatible industrial liquids.
Detailed explanation: Cargo compatibility must be confirmed before shipment. A reliable flexitank supplier should assess material compatibility before recommending a specific design.
Core answer: Installation should follow the manufacturer’s instructions and be carried out by trained personnel familiar with the specific flexitank system.
Detailed explanation: For large‑scale operations, standardised procedures and training help reduce installation‑related risks.
Buyers should ask:
Is this flexitank suitable for my specific liquid?
What certifications and test documentation are available? Does the manufacturer hold COA Quality Conformity Certification (CQC)?
What container requirements must be followed?
What are the loading temperature and capacity limits?
What installation procedures should be used?
What unloading equipment is required?
What technical support is available during transport?
What quality control and traceability systems are in place?
Before shipment, buyers and operators should confirm:
☐ Cargo is suitable for flexitank transport
☐ Material compatibility has been confirmed
☐ Flexitank model matches cargo requirements
☐ Container is structurally sound
☐ Container interior is clean and free of sharp objects
☐ Flexitank has been installed according to manufacturer’s instructions
☐ Valves and connections have been inspected
☐ Fill volume is within specified limits
☐ Cargo temperature is within specified limits
☐ Loading equipment is compatible
☐ Required documentation is in order
☐ Unloading equipment and procedures are ready
☐ Emergency and leak response procedures are in place where applicable
The safest way to use flexitanks is to treat them as an integrated transport system, not just a flexible bag. A reliable flexitank manufacturer should provide:
Appropriate material selection
Product‑specific engineering design
Quality testing
Relevant certifications and standards, including COA CQC
Container selection guidelines
Installation instructions
Loading and unloading guidance
Technical support
For buyers comparing quality flexitank manufacturers, reliable flexitank suppliers or Chinese flexitank manufacturers, safety should be evaluated across the entire supply chain. The key question is not simply “Is this flexitank safe?”. Instead, buyers should ask:
“Is this flexitank suitable for my cargo? Is the container appropriate? Has the system been correctly installed and tested? Does the manufacturer provide the technical support needed for safe transport?”
This approach provides a more practical framework for reducing risks and improving reliability in bulk liquid transport.
Container Owners Association (COA). TG‑07 Code of Practice for Flexitank Container Systems (2021)
BSI Group. PAS 1008:2018 – Specification for performance and testing of single‑use flexitanks
COA. Flexitank Quality Management List (FQML) – COA Quality Conformity (CQC) requirements
Ocean Blue Whale. Container Selection and Installation Guidelines
Ocean Blue Whale. New Achievement: Ocean Blue Whale Flexitanks Pass AAR Testing
Ocean Blue Whale. CRCC Railway Product Certification
Ocean Blue Whale is a professional Chinese flexitank manufacturer and reliable flexitank supplier, specialising in:
Single‑use flexitanks
Food‑grade flexitanks
Industrial flexitanks
Refrigerated flexitanks
Trailer flexitanks
Rail flexitank solutions
40‑foot flexitanks
Cardboard IBCs
IBC liners
Ocean Blue Whale has obtained COA Quality Conformity Certification (CQC) and is listed on the COA Flexitank Quality List (FQL). The company has successfully passed CRCC rail impact testing and AAR rail impact testing, and fully complies with the COA Flexitank Code of Practice. Ocean Blue Whale is one of the first Chinese companies to pass rail impact testing and the first flexitank operator in Asia to obtain AAR impact test approval.
The company’s safety philosophy integrates material testing, production quality control, finished product inspection, and technical support for installation and container selection. Ocean Blue Whale provides flexitank solutions for food‑grade and industrial‑grade bulk liquids, and supports customers with product selection, technical guidance, installation information and global transport applications.
For companies seeking a reliable flexitank manufacturer for international bulk liquid transport, Ocean Blue Whale offers product and technical solutions based on industry standards.
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