Why don’t my PTFE gaskets seal FRP, plastic and other light load flanges?
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Top Seals Articles
Find a reliable dry gas seal system for any application.
First of Six Parts
Follow the major developments in seal technology
This month's "Sealing Sense" was prepared by FSA member Larry Sheffield.
Proper safety precautions for selecting, installing and maintaining seal systems
The conformability, flexibility and wide range of material combinations and designs enable packing to seal many difficult, unconventional applications. These capabilities, coupled with other packing systems components, can provide effective sealing solutions that reduce the consumption of valuable water and energy resources.
As we learned last month, carbon/graphite fiber packings have proven to be effective solutions to many common sealing applications. This time, we have learned that flexible graphite packings appear to have become the packings of choice when sealing fugitive emissions, high heat media, and rotating equipment with limited cooling or flush available.
These basic seal system considerations can significantly reduce the energy footprint of the seal face interaction. Their contribution to the overall sealing system energy footprint should be considered after review of all the components of the sealing system's energy footprint.
Maintaining equipment uptime in a mining operation is essential. For one of South American's largest sulfurated copper mining organizations, unreliability simply wasn't acceptable, so they turned to one seal manufacturer to develop a pump sealing system improvement program using the Six Sigma methodology.
Manufacturers of braided packings are often asked to simply supply "A PTFE packing." Though this may seem a straightforward request, it generates questions that must be answered to ensure the correct PTFE packing for the application. A clear understanding of the differences between the various forms of PTFE braided packing will enable a selection of reliable sealing for the pump or valve.
Latest Seals Articles
Why don’t my PTFE gaskets seal FRP, plastic and other light load flanges?
Find a reliable dry gas seal system for any application.
First of Six Parts
Follow the major developments in seal technology
This month's "Sealing Sense" was prepared by FSA member Larry Sheffield.
Proper safety precautions for selecting, installing and maintaining seal systems
In the past, there were two ways to seal a pump: the mechanical seal method or the compression packing set. Either choice was subject to potential leakage and/or hidden costs. For compression packing users, pump leakage has become so widely accepted that many companies have focused on better ways to divert the leakage rather than eliminate the leaks.
Boiler and Pressure Vessel code contains rules for the design and construction of unfired pressure vessels. The design of bolted flanges requires that gasket constants referred to as m and y be used in the calculation.
It is easy to confuse graphite fiber packings with carbon fiber packings. In fact, the terms carbon fiber and graphite fiber are often used interchangeably, even by packing manufacturers. Both products are used to manufacture braided packings, and they both have relatively good chemical and temperature resistant properties. But there are differences, and each has its advantages and disadvantages.
Initial costs and life cycle costs affect which sealing method is chosen for an application. If a sealing device cannot be considered an investment or will not produce an immediate return, there is little incentive for a change or upgrade.
Columns and Blogs
In this multi-part series, we will investigate several aspects of centrifugal pump efficiency.
First of Five Parts
Since the original publication of this draft standard in the January 2008 issue of Pumps & Systems, I have received feedback, encouragement, numerous questions and criticism. The draft listed three basic levels of repair.
The McGraw-Hill scientific dictionary [5] states that a volute is "a spiral casing for a centrifugal pump... designed so that speed will be converted to pressure."
