“Harmonized” Gasket Testing

Abstract

The last years there has been a great effort on research and development on gasket testing for bolted joints in Europe and in North America. In Europe, a new standard for the calculation of flanged joints (EN 1591) was developed by the Technical Committee TC 74 of the European Committee for Standardization (CEN). This standard requires gasket factors which must be determined in accordance to the testing standard EN 13555. In North America, the ASTM Committee F03 on Gaskets was established to implement PVRC developed gasket test procedures in the code. Since many companies are operating worldwide, there is an interest in “harmonized” gasket testing procedures to minimize the costs and to raise the effectivity of the tests performed. Several information exchange meetings on gasket constants and gasket testing have been held, and there have been many discussions concerning the difference between the European and the American test procedures. Up to now, only the test procedure for leakage tests has been “harmonized”. Although there are still some differences in detail, the European gasket constants as well as the PVRC parameter can be determined with the new definition of the test procedure, theoretically. In this paper some tests are evaluated in both ways, the results show some mismatch. More tests (with several gasket materials) are necessary to prove the reliability of this procedure.

Leak rate investigation of expanded polytetrafluoroethylene flat gasket

“…To measure the leakage rate, test equipment "TEMES fl.ai1" fig. 2 was used with software controlling the effective gasket surface stress, supplying test gas under pressure and reading the mass of gas passed through the gasket [10,11,12]. Helium was used as the test gas in the test.…”

“…Tightness tests are conducted at room temperature, but it is also possible to conduct tests at elevated temperatures [4]. Gasket characteristics are standardized but differ in America and Europe [5]. There exist ePTFE gaskets with a diffusion barrier [6], with alternating layers of low and high density [7], with a locally increased density that leads to a reduction in the mass of gas passed through the gasket without it being clear what the effect of the increased density is on the leakage rate of the gasket.…”