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DIN EN ISO 18119 – Periodic Inspection and Testing of Gas Cylinders

Purpose and Significance of the Standard

The DIN EN ISO 18119 is a European harmonized standard that defines requirements, test methods, and evaluation criteria for the recurring inspection and testing of seamless gas cylinders and large cylinders made of steel and aluminum alloys.

The purpose of the standard is to ensure the operational safety of compressed gas cylinders throughout their entire service life and to detect safety-relevant damage at an early stage.

Scope and Areas of Application with Focus on Diving and Industrial Gas Cylinders

The standard applies, among others, to:

  • seamless gas cylinders made of steel
  • seamless gas cylinders made of aluminum alloys
  • large cylinders and pressure gas tubes

Typical Areas of Use

  • technical and industrial gases
  • breathing air and diving cylinders
  • medical gases
  • mobile and stationary compressed gas applications

Diving Cylinders

Diving cylinders are subject to special stresses due to frequent pressure changes, moisture ingress, saltwater exposure, and mechanical stresses during transport and use.

The DIN EN ISO 18119 ensures that:

  • corrosion in the interior and exterior is detected early
  • the cylinder neck and threads remain suitable for safe valve installation
  • the structural strength of the cylinder is maintained

Industrial Gas Cylinders

Industrial gas cylinders are used in a wide range of areas, e.g., for technical, medical, or specialty gases. Depending on the type of gas and environment, increased requirements for material and condition may apply.

The standard considers:

  • gas-specific effects on cylinder material
  • stresses from frequent filling and transport
  • different operating conditions in industry and commerce

Recurring Inspection and Test Intervals

The DIN EN ISO 18119 specifies that gas cylinders must undergo recurring inspection and testing at regular intervals. The specific test intervals depend on various factors, including:

  • the material of the gas cylinder
  • the type of gas contained
  • operating and environmental conditions
  • national legal and regulatory requirements

Preparation of the Gas Cylinder for Testing

Identification and Inspection

Before the actual testing begins, the gas cylinder is clearly identified. This includes manufacturer markings, serial numbers, and existing test marks.

Pressure Relief and Valve Handling

Depending on the test method and cylinder type, complete pressure relief is performed, and if necessary, the valve is removed or the test is conducted with the valve mounted, provided this is permitted by the standard.

External Visual Inspection

The external visual inspection serves to assess the general condition of the gas cylinder. In particular, the following features are checked:

  • corrosion and material loss
  • dents, deformations, and mechanical damage
  • cracks or notches
  • condition of coating, paint, and cylinder base

Internal Inspection

The internal inspection allows assessment of the interior condition of the gas cylinder. It is used, among other things, to detect:

  • internal corrosion
  • material degradation due to gases or moisture
  • deposits or foreign substances
  • damage to internal coatings

Inspection of Cylinder Neck and Threads

The cylinder neck and internal threads are checked using suitable gauges and testing equipment. The aim is to detect wear, deformations, or cracks that could impair safe valve installation.

Pressure Testing and Ultrasonic Testing

Pressure Testing

Hydraulic pressure testing is used to check the structural strength of the gas cylinder. Volume expansion and elastic behavior are evaluated.

Ultrasonic Testing (UT)

Ultrasonic testing is a non-destructive method for determining wall thickness and detecting material weaknesses. Under certain conditions, it can be used as an alternative or complement to pressure testing.

Marking and Documentation

After successful testing, the gas cylinder is marked according to the standard. In addition, test results are documented to ensure traceability and accountability.

FAQ – Frequently Asked Questions

Is DIN EN ISO 18119 legally required?

The standard itself is not a law, but it is often used as a technical basis for legal and regulatory requirements.

Does the standard also apply to diving cylinders?

Yes, because diving cylinders are seamless gas cylinders made of steel or aluminum.

Why are regular inspections particularly important for diving cylinders?

Due to moisture, saltwater, and frequent pressure changes, there is an increased risk of corrosion and material damage.

Does the standard also apply to industrial gas cylinders?

Yes, DIN EN ISO 18119 also applies to industrial gas cylinders made of steel and aluminum.

Who is allowed to perform the inspections?

Inspections may only be carried out by qualified personnel with suitable testing equipment.

Contact

Inspections according to DIN EN ISO 18119 can – depending on the application – be conducted or supervised in coordination with us in-house.

If you have any questions, please feel free to contact us.

Phone: +49 (0) 37206/84551
Email: info@high-tech-diving.org