Best Practices for Cartridge Mechanical Seal Installations

TutorialThe reliability of a mechanical seal depends on more than the design of the seal itself. It also depends heavily on the practices used to install the mechanical seal into the centrifugal pump or other equipment. The actual installation may occur in a controlled environment such as a factory or repair shop or it may occur out in the field in an installed pump. The people performing the installation range from skilled workers with significant experience with seals to general mechanics who have had little exposure to seals. Regardless of the situation, the steps taken during the installation process set the foundation for the ultimate success of the seal in operation. Different pump and seal designs may require different installation procedures but there are several key elements that are common across all installations. These include inspection of the equipment, general requirements for equipment condition, preparation for installation, installing the seal, setting the seal drive, removal of setting/shipping fixtures, and connecting the piping plan. While each of the steps is deceptively simple, the ability to identify and correct problems during the installation is critical

Pixie: A heterogeneous Virtual Coarse-Grained Reconfigurable Array for high performance image processing applications

Coarse-Grained Reconfigurable Arrays (CGRAs) enable ease of programmability and result in low development costs. They enable the ease of use specifically in reconfigurable computing applications. The smaller cost of compilation and reduced reconfiguration overhead enables them to become attractive platforms for accelerating high-performance computing applications such as image processing. The CGRAs are ASICs and therefore, expensive to produce. However, Field Programmable Gate Arrays (FPGAs) are relatively cheaper for low volume products but they are not so easily programmable. We combine best of both worlds by implementing a Virtual Coarse-Grained Reconfigurable Array (VCGRA) on FPGA. VCGRAs are a trade off between FPGA with large routing overheads and ASICs. In this perspective we present a novel heterogeneous Virtual Coarse-Grained Reconfigurable Array (VCGRA) called "Pixie" which is suitable for implementing high performance image processing applications. The proposed VCGRA contains generic processing elements and virtual channels that are described using the Hardware Description Language VHDL. Both elements have been optimized by using the parameterized configuration tool flow and result in a resource reduction of 24% for each processing elements and 82% for each virtual channels respectively.Comment: Presented at 3rd International Workshop on Overlay Architectures for FPGAs (OLAF 2017) arXiv:1704.0880

Field Troubleshooting Common Mechanical Seal Piping Plans

Tutoria

The Selection and Design of Dual Pressurized Liquid Sealing Systems

TutorialsDual 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

Dynamics of Political Opinion Formation including Catastrophe Theory

After Nazism and Communism new forms of totalitarianism fostered by religious fundamentalism have arisen at the turn of the present century. In view of this fact we present a parsimonious quantitative model designed to shed some light on the dynamics of the formation of totalitarian systems. The model is constructed according to the principles of “sociodynamics” that belongs to the broad field of nonlinear dynamic systems theory (NDS). It comprises two order parameters and four trend parameters. All of them are socio-politically interpreted. Stationary, stagnant and revolutionary system-phases are exhibited in 10 scenarios. The relation to catastrophe theory is discussed

Mechanical Seals

Discussion Grou

Advancements in Mechanical Sealing - API 682 Fourth Edition

TutorialsAPI 682 is the leading document for mechanical seals in petrochemical, chemical, and pipeline services worldwide. It has combined the aspects of seal design, testing, standardization, and applications to provide the users and OEMs alike with a common source of information for mechanical seals. As seal technology has advanced, the standard has expanded to incorporate new seal designs, materials, seal selection guidance, and piping plans. The current edition, the Fourth Edition, was published in May of 2014 and is now available for purchase. This tutorial will cover the major changes introduced in the Fourth Edition

Barrier And Buffer Fluid Selection And Considerations For Mechanical Seals

TutorialThe increased use of pressurized and non-pressurized dual mechanical seals has driven more installations to require the use of barrier and buffer fluids. While some end users have viewed the selection of barrier fluids as an afterthought, their selection is a critical aspect of the seal operation and reliability. A thorough application review requires an understanding of the mechanical seal, sealing system, pump, and process. Fortunately there is a large installed base of successful installations to guide barrier and buffer fluid selections. Through the careful selection of fluids and good operating practices, barrier and buffer fluids can help provide reliable dual seal operation