GE contracted Kalsi Engineering, Inc. (KEI) to perform actuator testing to determine the effective diaphragm area for the Model 37/38 actuator line and to develop a bounding effective diaphragm area tolerance to account for measurement uncertainties and manufacturing tolerances.
The GE sponsored test matrix includes Model 37/38 Sizes 9, 11, 13, 15, 18, and 24 actuators. The test matrix was primary defined to provide EDA data for actuators used in US nuclear power plants. The test matrix was primarily designed to facilitate the evaluation of the effects of stroke position, pressure, diaphragm materials, and measurement uncertainty. The test matrix also included with and without spring test configurations, two spring options for the same actuator size and model, and two diaphragm materials: Nitrile Elastomer and Silicone.
The test program provides reliable data for AOV design basis evaluations as required by the NRC RIS 2000-03. This paper presents the results for the Masoneilan Model 38 Size 11 diaphragm actuator, which show that EDA is strongly position dependent and weakly pressure-dependent.
As part of the project, a method for determining the required EDA tolerance to account for manufacturing variations was developed, which allows EDA determined by testing to be used across the product line.
Paper published with permission.