DooFlexi Flexitank        Overview   |   System Design   |   Material   |   Valves   |   Model & Type   |   Accessories   |   Installation   |   Production Technology   |   Certification

Flexitank Overview

Flexitank, known as flexibag, is one kind soft, high-strength, light-weight single-use large bladders with valves. It is designed to fit inside general purpose freight standard 20 foot ISO container. Flexitank logistics is for the bulk transportation of non-hazardous liquids that are not classified or regulated as dangerous goods.

As the China professional flexitank manufacturer, we introduce the most advanced technologies and material to produce the highest quality flexitank bag under the strictest quality standard. DooFlexi flexi tank is constructed from multiple Polyethylene (PE) layers and Polypropylene (PP) layer, with various valves. The capacity sizes are from a specific capacity ranging from 14 to 24m3. All the material is brand new, food grade, and compliant with EC and FAD regulations.

The common liquid includes oil, wine, diesel, diesel, palm oil. Somebody also uses it for water storage bladder tanks.

  • Click DooFlexi to know more our sister company 

Flexitank System Design

The system used for the transport of liquid commodity. While a flexitank is a single entity,
it operates as part of a system which includes the flexitank bag, its fittings, restraining system

DooFlexi flexitank system

Flexitank Material

Our material properties meet (higher) the requirements of PAS 1008:2016.
Multilayer flexibag consisting of polyethylene/polyethylene blend film with a sleeve.

Inner Polyethylene Liner (PE Film)

PP film is used to pocket the inner liquid. It also can protect the transported product from all external factors that might alter the original condition of the product contained in the flexitank. So the PE film must be high puncture resistance, high stretching resistance, and anti-rub properties.

Our PE film is manufactured with a unique special formula. Please refer below its typical characteristics. All our raw material is from Exxon Mobil and Dow. We test each roll PE film under the control of ISO 9001 Quality Management System.

Below is the typical characteristics of 0.125mm PE film.

Woven Polypropylene Outer Sleeve (PP)

The woven polypropylene outer sleeve is used outside to protect the PE inner bladder well. So its strength is very important. Our PP outer film sleeve is an integral molding tubular type design. No need to seam two sides. This design ensures the higher strength and more safety than the traditional two PP layers seaming design.

We use the highest grade brand new PP raw material from Sinopec. Never use the reclaimed material. It ensures our PP layers has greater performance on has a great performance on stretching resistance and anti-friction, also provide flexitank with best and reliable production.

Below is the typical characteristics of our common PP layer.


Tensile Strength at Break (MD/TD)


Elongation at Break (MD/TD)


Tearing Strength (MD/TD)


Total Impact Strength


Tensile Strength


Sawing Part Tearing Strength

≤25 (25-15%)

Elongation at Break (Warp/Weft)

Flexitank Loading and Discharging

SGS Certificated comply with FDA Standard  |  Maximum Pressure 0.8Mpa.

DooFlexi has four type valves for your choice: Butterfly Valves, Ball Valves, Auto Airvent, Manual Airvent.

We uses the special High-Strength polypropylene material, which is FDA and EC certificated. These PP valves have higher strength, high and low-temperature resistance,  corrosion resistance. It ensures the valves can work well under violent collision.

The valves are designed with threaded self-locking pull and securing cap. It ensures better tightness and safety. The special design bottom filter can prevent the valve from being suffocated by the inner PE layers.

Each valve is sterilized and tested before using. The common size is 3 inch. The 2 inch and 4 inch is valves are available upon request. We also can provide the adapter for your special request.

To protect the safety, the airvent can automatically to expel the inside air when the pressure reaches 1~2 psi.

√  Pressure≥0.5Mpa         √  Self-locking Plug & Securing Cap         √  Auto Pressure Release Airvent

Choose Ball Valve or Butterfly Valve?

What's the different ball valve with butterfly valve? How to choose it?

Ball Valve VS Butterfly Valve

Comparing with the butterfly valve, the ball valves can seal more tightly, higher flow velocity and has better resistance to pressure.

Max. Pressure of Ball Valve: 0.8Mpa
Max. Pressure of Butterfly Valve: 0.4Mpa

flexitank butterfly valves

2”/3”/4” Butterfly Valve

flexitank ball valves

2”/3”/4” Ball Valve

flexitank auto airvent

Auto Airvent

flexitank auto air vent

Manual Airvent

Flexitank Sizes and Type

Flexitank Standard (D4)

Flexitank Eco (D3)

Standard Model is our common flexitank type.

  • Inner Layer: 4 PE film
  • Outer Layer: 1 PP out sleeve
  • Capacity 16,000 ~ 24,000L
  • Three loading/discharge option
  • Top pressure release valve
4 layers flexitank

DooFlix Eco Model is design for econimical solution.

  • Inner Layer: 3 PE film
  • Outer Layer: 1 PP out sleeve
  • Capacity 16,000 ~ 24,000L
  • Three loading/discharge option
  • Top pressure release valve
3 layers flexitank

Thermostable Flexitank (TF)

High-temperature-resistant flexitank is a flexitank with our new heat-resistant material technology. It is specially designed bulk liquid cargo with high filling temperature like liquid bitumen/asphalt.


Features and Advantages:

  • Withstand 60-90℃, high pressure resistant, strong and durable.
  • Load 30% more than drums per 20ft container
  • Save 50%+ package cost than with drums per 20ft container
  • Inner bag can melt with the bitumen, do not influence its quality
  • Environment-friendly and convenient for operation

Volume: 16000L–24000L
Temperature: 60-90 degree centigrade
Application: Liquid road bitumen, chemicals with high filling temperature.

Wine Flexitank (WF)

Wine flexitank is a system specially designed for bulk wine transport. It designed with an additional EVOH layer between the PE and PP layers. This design performs well in protecting wine from oxygen, moisture or sunlight permeation.


Features and Advantages:

  • Save packaging and transportation cost than ISO tank
  • The superior performance of oxygen resistance
  • Safety food grade LLDPE inner layer
  • Environmentally friendly, degradable and recycled

Volume: 16000L–24000L
Oxygen transmission rate: ≤0.45 cm3/m2·24h·0.1Mpa.
Application: Wine, Fruit Juice Concentrate

BLBD flexibag
Bottom Load/Bottom Discharge
TLBD flexitank
Top Load/Bottom Discharge
TLTD flexitank
Top Load/Top Discharge

Corrugated Paper

1.4m height x 28m length

flexitank Corrugated Paper

Steel Bar

Various steel bars design for different request

flexitank steel bar

Bulkhead Board

Option: Cardboard, Hard PP and Steel

flexitank bulkhead board
flexitank installation

Advanced Production Technology

The whole production process is under ISO 9001:2008 control

DooFlexi commits to producing the highest quality flexibag to meet the needs of different customers. We continually keep to design and upgrade the
product technology and flexitank’s details following Safety First rule. Our experienced engineering team focuses on the research of new technology,
new material to reach the highest level. The quality and safety risk control of flexitank is regarded as the most important principle.
The skillful workers concentrate on each step and details of flexitank production.

flxitank production process

Trust Flexitanks

We strictly adhere to the requirements of PAS 1008:2016, EC, FDA, COA Code of Practice
to carry out Material Test, Leak Tightness Test of Valves, Flexitank System Rail Impact Test.

To see Flexitank System Rail Impact Test Video >>

ukas color
halal color

Do you want to know more information? 

Ocean, Air, Road or Rail, our experienced multi-skilled professional team are ready to serve you 7x24h. We supply flexitanks all over the world. The main services country includes Malaysia, Singapore, Indonesia, UAE, South Africa, India, NZ, USA, UK, Australia, Canada. For the flexibag disposal, you also can contact with us.

Contact us by email at or Mobile: +86-18560655892 (WhatsApp).
Visit our sister company DooFlexi to know more information.

flexitank inspection