Figure 1 : Component test according to VDI2290 for technical tightness π www . valve-world . net Valve World September 2024
Hydrogen plays a crucial role in both the energy transition and future technology . As hydrogen applications become more prevalent , there is an increasing demand for reliable sealing solutions that can withstand various hydrogen environments . In Germany , hydrogen falls under the scope of the Technical Instructions on Air Quality Control ( TA-Luft ), which sets limit values for substances that are harmful to humans or the environment . In accordance with these regulations , sealing materials for hydrogen applications must meet stringent requirements . These materials must provide mathematical proof of technical tightness as outlined in VDI 2290 , using calculations based on EN 1591-1 for round flange connections . This necessitates determining the EN 13555 characteristics of gasket materials , focusing on factors such as creep at elevated temperatures and maximum tolerated surface pressure . Modified , calendared third-generation PTFE gasket materials possess the necessary EN 13555 characteristics and are already widely used with media subject to TA-Luft regulations . These materials are suitable for applications involving emissions or substances that are harmful to humans or the environment , adhering to the specific limit values established in the TA-Luft .
PTFE GASKET PERFORMANCE
Sealability of PTFE gaskets in cryogenic and gaseous hydrogen environments
This article examines the technical tightness of modified PTFE gaskets in cryogenic and high-temperature hydrogen environments , presenting test results that demonstrate their exceptional performance and suitability for various applications in the valve industry .
By Thomas Schmitz , Application Engineer , Garlock GmbH
Research questions
This study aims to investigate the performance of modified , calendered third-generation PTFE gaskets under various hydrogen conditions . The following questions were addressed : 1 . How do these gaskets change in terms of hardness , tear strength , elongation at break and density when exposed to cryogenic hydrogen ?
2 . How do these gaskets change in terms of hardness , tear strength , elongation at break and density when exposed to gaseous hydrogen at 150 ° C ?
3 . Do modified , calendered third-generation PTFE gaskets achieve the same level of technical tightness in a hydrogen environment as they do in tests conducted with helium ?
4 . How do these gaskets perform in terms of sealability : a ) When manufactured from a single piece ? b ) When manufactured in segments or welded ? Additionally , the study examined the overall sealability of these gaskets under both cryogenic ( -196 ° C ) and high-temperature ( up to 200 ° C ) hydrogen conditions .
Test procedure
About the author Thomas Schmitz is a process engineer with more than 20 years of experience in the field of sealing technology . He works as a Senior Application Engineer Europe for Garlock GmbH and is a member of the ESA Flange Gaskets Division .
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T test
Test temperature [° C ]
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t test
Test timeline
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L 1 |
Determination of leakage at room temperature after installation ( RT ) |
L 2 |
Determination of leakage after temperature ageing |
L 3 |
Determination of the leakage after retightening the connection |
L 4 |
Determination of the leakage with retightening and after the 2nd temperature cycle |
p 0 |
Ambient pressure |
Test pressure / operating pressure |
p B
Figure 1 : Component test according to VDI2290 for technical tightness π www . valve-world . net Valve World September 2024
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