Technical Approach for the Reduction of Fugitive Emissions

Abstract

The demands on industry to reduce fugitive emissions are increasing, steadily. For the European Union the Integrated Pollution Prevention and Control (IPPC) directive determines emission levels. Individual countries can adopt even tighter legislation like the TA-Luft (“Technical Instructions on Air Quality Control”) in Germany. E. g. the TA-Luft gives specific emission levels for valves according to the German VDI guideline 2440 - Emission reduction in oil refineries. In industrial applications in which the demands of the TA-Luft have to be met only certified sealing materials can be used in future. There are several requirements the sealants must fulfill, the most important in this respect is the tightness proof in a first-time test according to VDI 2440. In this objective, new packing materials were developed to be in compliance with the TA-Luft needs. The knowledge of the material characteristic is the basis for the improvement of the tightness capability and therefore for the reduction of fugitive emissions. But in almost the same manner the mounting procedure of the packing rings is important. It is necessary to perform the mounting procedure in two steps: a pre-deformation step (high stress level for seating) and a prestressing step (stress level must meet tightness requirements). Mounting by use of torque wrenches is time consuming, if this 2-step procedure is followed. Thus, mounting by use of hydraulic tensioner becomes effective. In the paper the most relevant packing material characteristics and the necessary tests to determine these characteristics are summarized. Then the mounting tools for hydraulic tensioning are introduced. Finally, some results of packing tests according to VDI 2440 are presented.