In-operation Inspection Method of Valves by Heat Degradation Models for Valve Packings

EPRI 2000
Session: Major Component Inspection

In-operation Inspection Method of Valves by Heat Degradation Models for Valve Packings

M. Koike, Hitachi, Ltd. Power & Industrial System R&D Laboratory; K. Takeshima, Hitachi, Ltd. Nuclear Systems Division; T. Miyoshi, M. Kiyota, Y. Hosoda, K. Matsumoto, Japan Power Engineering and Inspection Corporation;

ABSTRACT

Therefore, weight loss is adopted as a heat degradation index of valve packings (gasket and gland packings). The long-term (_$B!A_(J10, 000 hours) weight loss was studied experimentally at high temperatures (200_$B!A_(J400 _$B!n_(J). From these results, a heat degradation (a weight loss) model was proposed based on chemical kinetics. The degradation model is able to estimate lifetime of packings and to determine the interval between valve inspections by comparing the calculated value with the limit weight for leakage.

The research was carried out by the Japan Power Engineering and Inspection Corporation (JAPEIC) which was entrusted by the Ministry of International Trade and Industry (MITI).

Publication Source: 2nd International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurized Components, May 24-26, 2000, New Orleans, Louisiana USA.
Publisher: EPRI - [Homepage]