Session: CT-01-01 The James R. Payne Memorial Session on Design and Analysis of Bolted Flange Joints - 1

Paper Number: 179219

179219 - From Test Data to Tightness Proof: Aligning Gasket Characterization Across Asme and en Standards 

Abstract: 

From Test Data to Tightness Proof: Aligning gasket characterization across ASME and EN Standards

 

The calculation of bolted flange joints depends strongly on how gasket behavior is represented in design rules. While both American and European standards recognize the importance of gasket data, their approaches differ significantly.

The European framework, defined in EN 1591-1 and supported by EN 13555 testing, explicitly requires gasket characteristics such as Qmin, QSmax, creep, and relaxation data. This creates a direct link between laboratory test results and tightness proof, which is essential for meeting modern emission control targets.

By contrast, ASME PCC-1 emphasizes assembly practices and bolt stress guidance. Appendix O introduces a set of stress parameters for evaluating joint performance, but does not define how these values are to be experimentally determined. Similarly, PVRC developed a tightness-based method using gasket constants also derived from testing. The PVRC gasket constants Gb and a, determined from two or more ROTT (Room-Temperature Tightness) tests, define the initial sealing performance line, offering a more realistic representation of gasket behavior than the traditional m and y factors of ASME Section VIII.

This presentation will compare the different approaches in ASME, EN 1591-1, and PVRC method, highlighting the gaps in standardized gasket characterization and discussing pathways toward harmonization of tightness proofs across codes.

Presenting Author: Stefan Hufnagel Amtec North America, Inc.

Presenting Author Biography: Stefan Hufnagel is a German mechanical engineer with over a decade of hands-on experience in the field of bolted flange connections. Since earning his Bachelor of Science in Mechanical Engineering, he has been deeply involved in gasket testing, stress analysis, and tightness evaluations in accordance with international standards such as EN 1591-1 and ASME.
Stefan plays a key role at AMTEC, where he has led numerous projects in the areas of gasket characterization, flange design, and high-temperature testing of industrial valves. After more than 10 years at AMTEC’s headquarters in Germany, he is now bringing his expertise to North America, currently based at AMTEC North America Inc. in Athens, Ohio.
His work bridges engineering, software, and training, supporting customers worldwide with practical solutions for reliable flange connections.

Authors:

Stefan Hufnagel Amtec North America, Inc.