Dry Gas Seals. Wet Seal to Dry Gas Seal Conversion - Considering the Benefits of Retrofitting Your Compressor

Abstract

Tutorial 19C: Dry gas seals are specified in most of the new centrifugal compressors; yet many installed units are still equipped with conventional oil sealing systems. The benefits of dry gas seals conversions from traditional oil seals to dry gas seals are usually advantageous to compressor operators. However, end users should ask themselves several questions before deciding to retrofit their compressors with dry gas seals. The decision to retrofit a compressor with these upgraded seals may be dictated by economic factors, HSE constraints or technical considerations. Users should consider all of these factors when deciding whether or not to upgrade a compressor with dry gas seals. In addition, the following precautions should be taken during project execution to ensure successful conversion: perform a detailed physical integration analysis of the dry gas seal in the existing compressor; conduct a detailed rotor dynamic analysis; select the proper gas seal system design for the compressor; and plan for operator training. This paper will discuss the factors end users should consider before upgrading to dry gas seals together with an economic evaluation, and the steps that should be taken to ensure a successful conversion once the decision is made to retrofit a compressor with dry gas seals.