CEN/TC 208/WG 4 - Seals and diaphragms for gas appliances and gas equipment.

This document specifies requirements and test methods for unsintered polytetrafluorethylene (PTFE) tapes and polytetrafluorethylene (PTFE) strings (PTFE tapes or PTFE strings, for short) which are suitable for sealing threaded metallic joints as specified in EN 10226-1:2004.
This document covers two classes of PTFE tapes and PTFE strings suitable for fine (F) and coarse (G) threads.
The PTFE tapes and PTFE strings are used as sealing materials for metallic threaded joints in contact with 1st family gases (town gas), 2nd family gases (natural gas) and 3rd family gases (liquefied petroleum gases (LPG)) up to 500 kPa, up to 700 kPa for hot water of heating systems, and up to 20 kPa in gas appliances and their auxiliary equipment. The maximum working pressure covered in this document is 2000 kPa which is relevant to LPG storage. The temperature range is limited to −20 °C to 125 °C.

This document 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, bio methane and bio LPG, in the same quality, are covered. It also establishes a classification based on temperature range and hardness. This document is applicable 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 this document, tolerances have been made in the requirements specified by Annex A for the components with respect to those specified for standard test pieces.
The range of operating temperatures covered by this document is –40 °C to +150 °C.
For applications with potential condensation, this document 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.

This document 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, bio methane and bio LPG, in the same quality, are covered. It also establishes a classification based on temperature range and hardness. This document is applicable 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 this document, tolerances have been made in the requirements specified by Annex A for the components with respect to those specified for standard test pieces.
The range of operating temperatures covered by this document is –40 °C to +150 °C.
For applications with potential condensation, this document 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.

This document specifies requirements and test methods for unsintered polytetrafluorethylene (PTFE) tapes and polytetrafluorethylene (PTFE) strings (PTFE tapes or PTFE strings, for short) which are suitable for sealing threaded metallic joints as specified in EN 10226-1:2004.
This document covers two classes of PTFE tapes and PTFE strings suitable for fine (F) and coarse (G) threads.
The PTFE tapes and PTFE strings are used as sealing materials for metallic threaded joints in contact with 1st family gases (town gas), 2nd family gases (natural gas) and 3rd family gases (liquefied petroleum gases (LPG)) up to 500 kPa, up to 700 kPa for hot water of heating systems, and up to 20 kPa in gas appliances and their auxiliary equipment. The maximum working pressure covered in this document is 2000 kPa which is relevant to LPG storage. The temperature range is limited to −20 °C to 125 °C.