ptfe
- July 24, 2018
FFKMs, also known as perfluoroelastomers, were first developed in the 1960s for applications involving high temperatures and/or aggressive chemicals. Perfluoroelastomers exhibit many properties similar to PTFE (polytetrafluoroethlyene, or Teflon®), and are considered inert in almost all solvents. However, PTFE is a plastic, and when compressed, it will not recover to its original shape. On the other hand, elastomers contain crosslinks, which act as springs to give the material resiliency and the ability to recover after a part has been compressed - this resistance to permanent compression gives the material the ability to maintain a seal over time. (To learn more about perfluoroelastomers, download our Introduction to Perfluoroelastomers White Paper).
The article below was recently published on FlowControlNetwork.com, and discusses how FFKMs are being used in oil & gas exploration, as production companies are increasingly operating in high-pressure, high-temperature (HPHT) downhole conditions.
HOW FFKMS PROTECT COMPONENTS IN ENHANCED OIL RECOVERY OPERATIONS
Companies are increasingly operating in high-pressure, high-temperature downhole conditions.
Improving technologies and methods to increase the recovery of oil from existing reservoirs is a global challenge. In the U.S., oil production at reservoirs can include three phases: primary, secondary and tertiary (or enhanced) recovery. The U.S. Department of Energy (DOE) estimates that primary recovery methods — which rely on the natural pressure of the reservoir or gravity to drive oil into the wellbore, combined with pumps to bring the oil to the surface — typically tap only 10 percent of a reservoir’s oil. Furthermore, secondary efforts to extend a field’s productive life — generally by injecting water or gas to displace oil and drive it to a production wellbore — still only push recovery totals to between 20 and 40 percent of the original oil in place. Clearly, much untapped oil and gas remains in existing wells.
- January 11, 2018
Sealex® joint sealant, specially processed, 100% pure PTFE on a roll, provides soft, highly compressible gasketing for longer life and trouble-free sealing. Its form-in-place versatility also cuts maintenance and storage costs. The high compressibility of Sealex® enables it to effectively fill flange imperfections for a tight, leak-free seal. Under pressure, it provides a very wide, thin ribbon-like joint sealant. Unlike conventional PTFE which is prone to cold flow, Sealex® has good creep resistance and bolt torque retention properties.
Sealex® joint sealant does not support bacterial growth or cause product contamination and is FDA compliant. It has virtually no shelf-life concerns since PTFE is unaffected by normal environmental conditions.
It has excellent resistance properties to chemical attack. It is ideal for most chemical services at temperatures to 500°F (260°C) and pressure to 2,000 psi (138 bar). It is also suitable for cryogenic use to -321°F (-196°C).
- June 06, 2017
Polytetrafluoroethylene (PTFE) is commonly known as a coating for pans under the DuPont trade name Teflon™. It is also superbly suited as a sealant and is superior to many materials in specific ways. For example, it can be used at low and high temperatures and in combination with gasoline, solvents, water and other polar media such as lyes, standard lubricants and brake fluid. PTFE’s chemical resistance is nearly universal.
History
In 1938, while working for DuPont, American chemist Roy Plunkett was looking for a substitute for the fluorohydrocarbon Freon, which his employer was only allowed to sell to General Motors’ Frigidaire division for patent-related reasons. For his research, he had obtained a supply of tetrafluoroethylene (TFE), which was used as refrigerator coolant. He stored it in small pressurized gas cylinders at low temperatures. When he was ready to use the gas after a fairly long storage period, none was left in the container. But its weight was unchanged. After it was opened, there were white crumbs inside and the inner walls of the container were covered with a thin layer. Plunkett quickly realized that the TFE gas had been polymerized into a plastic. This new plastic, PTFE, proved to be completely resistant to chemical exposure. Not even aqua regia¹ could harm it in any way. But its production was so costly that practical uses seemed inconceivable.
- March 21, 2017
Gallagher recently released our Introduction to Perfluoroelastomers White Paper, available for download on our site. This was written by Russell Schnell, a current contracted employee of Gallagher Fluid Seals, and more importantly, a former Senior Application Engineer with the Kalrez® perfluoroelastomer parts business at DuPont. The following excerpt is the first section of the White Paper, discussing the history or elastomers and perfluoroelastomers, and the chemistry that helped create these modern materials.
Introduction to the World of Perfluoroelastomers
The use of elastomers is widespread in our world. Elastomers have many uses including: sealing fluids, for tires, in chemical plants, in semiconductor manufacturing equipment, for dust and moisture seals on cell phones, and seals on aircraft engines. The function of the elastomer and technology involved can vary from something as simple as a barrier to rain water, to seals in automobile engines, to critical sealing applications on the Space Station. Selection of the correct elastomer in an application is very important for successful and long term equipment operation. Although many different elastomers exist in the marketplace, when the highest service performance is needed, in terms of chemical and high temperature resistance, the choice is perfluoroelastomers.A perfluoroelastomer can be represented by the letters: FFKM or FFPM (ASTM and ISO designations, respectively). The word itself has two parts, perfluoro (meaning fully fluorinated), and elastomer. Perfluoroelastomers exhibit many properties similar to PTFE (polytetrafluoroethylene), which is also fully fluorinated and considered inert to almost all solvents. PTFE is often referred to as Teflon®, which is a registered trademark of The Chemours Company. PTFE is a plastic, and when compressed, will not recover to its original shape. However, elastomers contain crosslinks, which act as springs to give the material resiliency and the ability to recover after a part has been compressed. This resistance to permanent compression (compression set) gives the material the ability to maintain a seal over time. Finally, while whereas plastics are crystalline, elastomers are amorphous at room temperature; they can be easily compressed and will mold themselves to maintain a seal. Given the chemical structure and performance similarities of FFKMs to PTFE, perfluoroelastomers are sometimes referred to as an elastomeric form of PTFE.
- January 10, 2017
GORE® Gasket Tape is a 100% ePTFE form-in-place gasket that delivers worry-free sealing performance for large steel flanges (Series 500) and large glass-lined steel equipment (Series 1000). While this product has a number of advantages, GORE® has now made their gasket tape line even easier to use.
Improved installation-aid adhesive.GORE® has upgraded the removable adhesive backer on GORE® Gasket Tape Series 500 and Series 1000 to a new higher strength material. This ensures that when the backer is removed at installation, it peels away in one easy-to-remove piece.
- January 05, 2017
There are many factors to be considered when choosing the right type of hose for your application. There are many different types of hose available on the market. They include metal, rubber, composite, PTFE and fabric. The decision of which hose type to buy depends on the application for which the hose is being used.
Metal hose is ideal for absorbing vibration, misalignment correction, thermal expansion or contraction of piping systems, and protecting equipment from excess motion. Typically, metal hose is used when no other (non-metallic) constructed hose will work. In other words, metal hose is used as a last resort.
Here are some of the factors that should alert you it's time to use metal hose:
- August 23, 2016
Today we’ll continue our look at spring-energized seals by exploring some of the preliminary considerations to made when working with these seals.
A spring energized PTFE seal is selected to fit an exact set of service conditions found in your application.
Gallagher Fluid Seals recommends conducting a review of the entire sealing environment. You should use the Engineering Action Request (EAR) form before selecting a seal design.