Venting systems (pressure relief - vacuum relief - pressure equalizer caps)

  • When to use them?
  • The risks associated with deformed packaging
  • Examples of systems
  • Prohibitions, obligations and precautions for use

 

 

When should I use a venting system?

When the container may bloat:

•    because of the gas released by the contents (often the case for pesticides, fertilizers, detergents, disinfectants, hydrogen peroxide, bleach)
•    due to a change in pressure (pressure drop due to altitude changes)
•    when subjected to sharp temperature increases

In these cases, use a pressure relief or pressure equalizer cap (if the product is not sensitive to oxidation by oxygen in the air).


Conversely, when the package may collapse:
•    because of the oxygen consumed by the contents,
•    due to a pressure change (increase in the atmospheric pressure),
•    when subjected to sharp temperature drops (e.g., temperature change or hot-fill process)

In these cases, use a vacuum relief system or pressure equalizer system

 

The risks associated with deformed packaging

•    aesthetic problem
•    instability during storage and transportation = risk of falls
•    bursting or cracking = health risk if dangerous goods

 

Examples of venting systems

=> For plastic drums withbungs

2" PP pressure equalizer cap withmicroporous membrane

2'' PP vented cap with black EPDMvalve

2" DIN PP pressure equalizer cap withmicroporous membrane

Click on the visuals to find out more

=> For metal drums with bungs

2'' vacuum relief cap - black EPDM valve

2'' steel vacuum relief caps - black EPDM valve

2'' steel pressure relief caps - black EPDM valve

For more information, please contact us

=> For jerrycans

PE 45DIN tamper-evident pressure equalizer cap with microporous membrane

PE 60/61DIN tamper-evident pressure equalizer cap with microporous membrane

Click on the visuals to find out more

MPV3 -Tri-Sure® - 60/61DIN - tamper-evident pressure equalizer cap with microporous membrane - gas exchange via the threads

For more information, please contact us

=> For plastic bottles

Tamper-evident PP - 42mm - pressure equalizer cap

Tamper-evident PP - 32DIN-E - pressure relief cap

Click on the visuals to find out more

Prohibitions, obligations and precautions for use

Prohibitions / Obligations

1 => Air transport prohibited for any packaging equipped with a venting system.

2 =>ADR regulation - paragraph 4.1.1.8: "Where pressure may develop in a package by the emission of gas from the contents (as a result of temperature increase or other causes), the packaging or IBC may be fitted with a vent provided that the gas emitted will not cause danger on account of its toxicity, its flammability or the quantity released, for example.
A venting device shall be fitted if dangerous overpressure may develop due to normal decomposition of substances. The vent shall be so designed that, [...] leakages of liquid and the penetration of foreign substances are prevented under normal conditions of carriage."


3 => Packaging containing liquid shall be transported and stored upright. This is also the case for vented packaging, which must also include orientation arrows indicating the direction of transport and storage (see ADR regulations - paragraph 5.2.1.9). This includes "combination packagings having inner packagings containing liquids".


4 => TDG approval: for all packaging for transporting dangerous goods, the packaging + type of closure must have an approval certificate.
Packagings fitted with vents undergo drop and stacking tests but no pressure tests.
It is important to check the approval certificate to find out what reference liquid the vented cap has been approved for. Read our Tip of the Month on Transporting Dangerous Goods

Precautions / Recommendations

Packaging Closure: Tighten to the recommended torque.

Chemical compatibility: Respect the chemical compatibility between the packaging + type of closure and the packaged product by performing appropriate testing.

Crystallization: Check if your product is likely to crystallize or form a deposit on the membrane, which may interfere with the gas exchange.
There are vent caps suitable for this type of product, equipped with a protective cover or a special "oleophobic" membrane (e.g. the. MPV3 -Tri-Sure®).
 
Venting speed: Test the venting speed (cm3/minute) to make sure the venting system meets the needs.

Special packing provision: Check the ADR to see if there is a special packing provision for your product that requires you to use a vent.
For example, for product UN 1791, the Packaging Instruction is No. P001, and for this product, packaging provision PP10 states that "The packaging shall be vented."  
Please note, for certain dangerous goods such as bleach - Hazard Group III, there is no specific provision.
In that case, determine whether there is a risk of overpressure. If so, refer to paragraph 4.1.1.8 of the ADR (see point 2 of prohibitions / obligations above).

Transport:
-Ensure that the cap is oriented upwards (see point 3 of prohibitions / obligations above )
-Ensure proper ventilation of the vehicle

Venting natural products: Venting issues may arise for natural products such as fertilizer from seaweed or prepared foods containing cabbage.

Venting systems for food: Please note that very few venting systems are suitable for food contact

Venting systems and tamper-evident seals for drums: For drums, if you want to use a tamper-evident seal, you will have to choose a perforated seal or a porous PE seal, preferably yellow in colour (reference colour specified by ISO 20848-3: 2006 for easier identification of packagings fitted with a venting system).

      This Tip of the Month on Venting Systems was written in collaboration with our partner Tri-Sure     


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