Session: OAC-02-01 Qualification and Testing

Paper Number: 152865

152865 - Gasket Sealing Characterization for Bolted Flange Joint in Cryogenic Conditions at -180°c 

Abstract: 

The industrial challenges of mastering the sealing systems of fluidic equipment involve reducing the risks of emissions during both normal operation ("fugitive emissions") and/or accidental conditions for safety, environmental, and economic reasons, while also considering durability and energy efficiency.

As part of its Strategic Sector Project concerning the tightness of fluidic equipment, Cetim has developed a test apparatus to characterize the performance of seals and/or metal-to-metal contact interfaces under cryogenic conditions at -180°C with LN2 circulation. A test campaign was carried out on a selection of seals incorporating different sealing materials (graphite, PCTFE and Vespel®) as well as metal-to-metal contact interfaces. The test procedure aims to characterize the mechanical behavior, and the sealing levels based on a representative initial tightening level, but also to evaluate the ability to maintain a good sealing level during loosening. Additionally, a specific campaign was also conducted by introducing surface defects on the sealing face to assess the robustness of the tested solutions.

The results show the ability of different sealing interfaces to maintain there sealing performances after mechanical cycling in nominal conditions. The introduction of surface defects shows a variability in terms of sealing performances between the different materials with one material that has the same performances in nominal conditions and degraded conditions. The test results on metal-to-metal interfaces shows the impact of the surface roughness on the sealing performances.

As part of this project, a numerical study was also carried out to develop a model based on finite element analysis of an NPS 8 CLASS 300 valve. The objective of this model is to verify the reliability of the numerical model regarding the thermomechanical multiphysics phenomena within the valve for use under cryogenic conditions (LN2). The results of the tests were used to calibrate the numerical model.

This presentation details the test apparatus and the results obtained on the different configurations tested during the campaign, as well as the numerical model established on an NPS 8 CLASS 300 valve.

Presenting Author: Stéphane Javanaud Cetim

Presenting Author Biography: I work at Cetim company (French Technical Center) since 2016 directly after being graduated from an engineering school.

I've gained experience in in the field of bolted flange joints, elastomeric seals and Finite Element Analysis.

My areas of expertise are :

- Gasket testing: definition of test procedures for gasket characterization and qualification for gasket manufacturers and end-users in the field of Oil&gas, Nuclear and chemical industry

- Bolted flange connection calculation:
- Training for industry on bolted flange joints and EN1591 calculation method,
- Several studies around EN1591,

- Sealing interfaces calculation by FEA with elastomeric O-ring / gasket or metallic O-ring

I'm Co-Author of two publications :

- Materials and Design volume 156 (2018): Temperature-dependent modelling of a HNBR O-ring seal above and below the glass transition temperature.

- ASME PVP 2018: Flange Gasket Behavior Characterization for Service in Arctic Environment (PVP2018-84284).

Authors:

Stéphane Javanaud Cetim
Hubert Lejeune Cetim
Cédric Boulben Cetim