What is BS EN 549 – Rubber materials for seals and diaphragms about?
BS EN 549 specifies requirements and associated test methods for rubber materials used in gas installations, gas equipment and gas appliances in contact with 1st, 2nd and 3rd family combustible gases as classified in EN 437:2018, additionally, LPG, biomethane and bio LPG, in the same quality, are covered.
BS EN 549 also establishes a classification based on temperature range and hardness.
BS EN 549 applies to materials from which homogeneous seals and homogeneous or reinforced diaphragms are manufactured.
Since the dimensions and shape of the components differ from those of standard test pieces taken from sheet material as used for type testing of the rubber materials according to BS EN 549, tolerances have been made in the requirements specified by Annex A for the components concerning those specified for standard test pieces.
The range of operating temperatures covered by BS EN 549 is –40 °C to +150 °C.
For applications with potential condensation, BS EN 549 is not applicable for silicon rubber, e.g. above 200 hPa (200 mbar) nominal pressure or at temperatures below 0 °C with 3rd family gases.
Who is BS EN 549 – Rubber materials for seals and diaphragms for?
BS EN 549 on Plastics and rubber machines is relevant to:
- Manufacturers of rubbers seals
- Chemical engineers
- Health and safety bodies
- Any entity responsible for testing and safety of the gas appliance
Why should you use BS EN 549– Rubber materials for seals and diaphragms?
Seals are used to prevent gas leakage in gas appliances so that there is no risk of injuries or accidents, BS EN 549 specifies the requirements for rubber materials to be used for the manufacture of seals and diaphragms. It specifies for that purpose, tests to be carried out on standardized test pieces taken from sheets of material since the small size of most components, in general, does not allow the preparation of necessary test samples for carrying out the complete range of tests.
Overall, BS EN 549 is a comprehensive guide that provides methods and requirements for rubber materials used for the manufacture of seals, so manufacturers will gain a better understanding of the process and the product's end quality, durability, and efficiency.
What’s changed since the last update?
BS EN 549:2019 supersedes BS EN 549:1994, which is withdrawn and includes:
- Clause 8, “Evaluation of lifetime for material used to manufacture seals” added
- Clause 9, “Infrared spectra of the material” added
- Resistance to condensate/liquid phase of combustible gases added
- Low-temperature classes added
- Ozone resistance for diaphragms is now mandatory