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Teadit : Reliable Sealing Through Origin ®
In the world of fluid sealing and gaskets , the story begins and ends with gasket stress . At its most basic level , bolted flange joint reliability depends on adequately loading a gasket to create and maintain a seal . While this sounds simple enough , experience has shown that the process of effectively sealing an industrial system is ripe with challenges .
With all these factors to consider , it can be challenging to seal standard pipe flanges , and these challenges can often be exacerbated in specialty equipment , vessels , and flanges . Stainless Steel World Americas had the pleasure of speaking with TEADIT to discuss how some of the most difficult applications to seal are those that are torque limited to low clamping forces , such as lined vessels and MONDI™ piping .
By Sara Mathov
John Bickford , in his book “ Gaskets and Gasketed Joints ,” suggests that there can be hundreds of variables influencing joint reliability . These types of connections often require special consideration when it comes to gasket selection , as many traditional gasket technologies are not able to effectively seal under such low load conditions . Historically , both lined equipment and MONDI™ piping applications have utilized tailored approaches to sealing .
What is MONDI™ Piping ?
Developed by the Monsanto Company , MONDI™ piping is made with a special alloy of ductile iron that can handle high concentrations of sulfuric acid up to 300 ° F . ( MONDI™ derives its name from MONsanto and Ductile Iron ). This special metallurgy provides a longer operating life in this aggressive service due to its corrosion resistance characteristics . However , the flange connections for MONDI™ piping have limited load capacity , so the applied torque , and subsequent clamping forces , are lower than in traditional flanged connections .
To account for this low-load condition , the traditional approach for sealing MONDI™ flange connections has been to utilize a step ring-type gasket . These gaskets feature a traditional ring gasket with a second , narrower ring affixed or machined into the face of the carrier gasket , to develop a stepped profile . The idea behind this design is that the applied load can be concentrated on the smaller raised profile . Since stress is simply the applied force distributed over the contact area of the gasket , this provides the desired effect of minimizing the surface area to maximize the developed sealing stress .
Origin ® close up .
The facing on MONDI™ flanges can also create challenges for less compressible ( i . e . harder ) gasket materials . These special considerations can make sealing MONDI™ pipe flanges challenging .
monly manufactured from PTFE-based materials that exhibit an indefinite shelf-life , the same is not true of the adhesive . Over time , gaskets being stored on site can delaminate . Finally , layered PTFE gaskets exhibit more creep than single-layer gaskets due to ‘ slippage ’ between the layers . Gaskets count on the friction created at the flange surface interface to help restrict and resist creep .
Introducing Origin ® Technology
In 2017 , as part of a continuous search for better performance and sustainability , Teadit introduced its pat-
Most step ring-type gaskets utilize two separate layers of material held together with an adhesive layer . This creates several sealing concerns . First , the adhesive layer provides a potential leak path through the body of the gasket . Second , while these gaskets are comented , and award-winning , Origin ® technology used to manufacture PTFE gaskets . This process produces gaskets made from sintered and wound PTFE tape .
Tapes may be with or without fillers , expanded or not , with or without pigments . There are nearly infinite combinations to create the most suitable gasket product for each application . Different additives can be used in different regions of the gasket to have specific characteristics , including varying colors to identify these properties . Additionally , this technology allows the manufacture of thicker or large diameters gaskets without splices .
Another feature of this technology is the reduction of waste , since the fabrication of gaskets from the cutting of sheets is extremely inefficient , causing waste that can reach more than 60 % of the sheet material . Origin ® technology reduces process losses to virtually zero while substantially reducing environmental impact . In 2018 , Origin ® technology was recognized by The Chemours Company , receiving the Plunkett Award , which highlights innovations based on the use of fluoropolymers . It went on to be recognized three more times by winning the Plant Engineering ‘ Product of the Year ’ award in 2018 , a Vaaler Award in 2019 , and was also recognized by the Downstream Awards .
Origin ® APF-510 for Sulfuric Acid Piping
TEADIT engineers ’ study of the use of Origin ® technology in acid piping applications has led to the development of the Origin ® APF-510 gasket ; a soft gasket with an impermeable sealing barrier for sulfuric acid process piping . It is designed to meet the specific conditions of piping where the flanges often have scratches , corrosion , or other irregularities .
2 Stainless Steel World Americas - August 2023 | www . ssw-americas . com