The Selection and Design of Dual Pressurized Liquid Sealing Systems

Abstract

Dual mechanical seals represent one of the most common approaches to improving seal reliability and reducing process emissions. While the presence of the pressurized barrier fluid provides significant benefits, the challenge for the end user is to select the most appropriate method of creating this pressurized environment. Fortunately there are several defined options for piping plans which describe the general characteristics of a dual pressurized sealing system. This however is just the starting point. The user must consider the impact of the seal design, the operating environment of the pump, and the considerations and risk assessment for upset conditions in their system evaluation. Other factors include maintenance requirements and seal monitoring strategies. Finally the selection of individual components for the systems will be dictated by operational requirements, local codes, and customer preferences. All of these considerations will require that the end user use a complete, systematic evaluation of their application in specifying the most appropriate system.