Fastener Spacing & Tightening Torque of Gasket Joints of Oil Filled Transformers

Abstract

Objectives: Design of leak-proof gasket joint of the transformer is very important to ensure the safe long-term service of a transformer. This paper gives the properties of gaskets, fastener spacing calculation and recommended tightening torque values. Methods/Statistical Analysis: This study commences with a review of the equations applicable for the calculation of leak rate of gas and oil through a gasket joint. Findings: A comparison of properties of various types of gaskets used is carried out and NITRILE Rubber and NITRILE Cork gaskets are selected as the most suitable ones for transformer application. The procedure to calculate the fastener spacing and the recommended tightening torque values are given. Application/Improvements: This paper is useful for the transformer designer because the gasket types and parameters fastener spacing calculation and torque requirements are not consolidated in any published paper. Further studies to determine the relationship of surface finish, gasket characteristics, fastener spacing and tightening torque on the long-term performance of the transformer. Keywords: Distribution Transformers, Gasket, Tightening Torque, Fastener Spacing, Oil-Filled Transformers