Simple pressure vessels are defined as welded pressure vessels manufactured in series with an internal overpressure of more than 0.5 bar. They are intended to contain air or nitrogen, and should not be exposed to flames.

Furthermore, a number of other limitations apply to the properties of these products:

  • the parts and compositions contributing to the pressure resistance of the vessel are made of either unalloyed high quality steel, unalloyed aluminium, or unhardened aluminium alloys;
  • the pressure vessel must consist of:
  • either a cylindrical part with a circular cross-section, sealed by arched floors with the hollow side pointing inward and/or by flat floors. These floors have the same axis of rotation as the cylindrical part;
  • or two arched floors with the same axis of rotation;
  • the pressure vessel's maximum operating pressure must be equal to no more than 30 bar and the product of this pressure and the contents of the container (PS.V) is no larger than 10,000 bar;
  • the minimum operating temperature must not be lower than –50°C and the maximum operating temperature must not be higher than 300°C for steel pressure vessels and 100°C for aluminium or aluminium alloy pressure vessels.


The general safety regulations for simple pressure vessels are prescribed in the Code of Economic Law, Book IX on  the safety of products and services.

These stipulations are supplemented and further expanded upon in the Royal Decree of 1 April 2016 on placing pressure vessels on the market. This decision transposes European Directive 2014/29/EU of 26 February 2014 on the harmonisation of the laws of the Member States relating to the placing on the market of simple pressure vessels.
Directive 2014/29/EU is a revised version of Directive 2009/105/EC, whose requirements were the topic of the Royal Decree of 11 June 1990 (as amended by the Decrees of 19 May 1992, 5 May 1995 and 6 December 2005), repealed on 20 April 2016, the date on which the new Directive entered into force.

The following pressure vessels are excluded from the scope of the Royal Decree:

  • pressure vessels specially designed for nuclear use, and which could cause the spread of radioactivity if defective;
  • pressure vessels specifically intended for installation on or propulsion of ships and aircraft;
  • fire extinguishers.

Pressure vessels placed on the market prior to 20 April 2016

The simple pressure vessels covered by the aforementioned Royal Decree of 11 June 1990, and in conformity with this Decree, that were placed on the market prior to 20 April 2016, may continue to be placed on the market and/or be commissioned. Certificates in conformity with the Royal Decree of 11 June 1990 issued by recognised inspection bodies are valid.

Obligations for economic operators

The new regulations introduce new obligations for all economic operators involved in the sales chain for simple pressure vessels, with a view to increasing the responsibility of all who play a role in the safety of the products and to ensure better collaboration with the inspection authorities, both in Belgium and abroad.

Thus, all operators are concerned and must take appropriate measures to avoid a non-compliant pressure vessel being traded and they must ensure that the vessels are traceable within the sales chain.

Obligations for manufacturers

For pressure vessels where the product of PS.V is greater than 50 bar:

  • drawing up the technical documentation;
  • designing and manufacturing pressure vessels that meet the essential safety regulations, as described in Annex I of the Royal Decree;
  • before the pressure vessels are manufactured, subjecting them to an EU type investigation;
  • before the pressure vessels are traded, subjecting them (in line with the product of PS.V) to one of the conformity assessment procedures (based on the internal production inspection and, where necessary, tests carried out under supervision); these procedures are described in Annex II of the Royal Decree;
  • draw up an EU declaration of conformity (must be stored for 10 years);
  • apply the CE marking to the compliant pressure vessels, along with the following inscriptions:
  • the maximum operating pressure (PS in bar);
  • the maximum operating temperature (Tmax in °C);
  • the minimum operating temperature (Tmin in °C);
  • the capacity of the vessel (V in l);
  • the manufacturer's name, trading name or trademark, along with their address;
  • the type and the serial or batch number of the pressure vessel.

For pressure vessels where the product of PS.V is lower than or equal to 50 bar:

  • apply the relevant rules in force;
  • apply the necessary inscriptions for their identification and safe use (see above);
  • however, the CE marking must not be applied in any circumstances.

Disputes and complaints

If you have a complaint about simple pressure vessels as a consumer, you can address it to the Helpdesk.

If you are a manufacturer and the product you have been trading carries a safety risk, you must inform the Central Helpdesk for Products.

Last update
3 November 2021

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