Fiber Reinforced Plastic (FRP) pipes and flanges are increasingly used in the oil and gas industry where metal is simply too heavy and expensive. In addition to cost pressure, the need for lightweight chemically resistant materials are also driving the use of fiberglass pipes and flanges. Innovations in FRP flange design coupled with improvements in manufacturing technology have allowed FRP piping to be used in even more demanding applications. However, these demanding applications have added challenges for sealing the bolted flange connections.
More aggressive media and higher internal pressures have pushed the limits of the commonly used rubber gasketing materials, such as Nitrile Butadiene Rubber (NBR), Ethylene Propylene Diene Monomer (EPDM), or neoprene. Obtaining a reliable seal in FRP flanges using conventional gasketing materials has become more difficult.
Fiberglass pipes are generally known to have strength limits and a lower pressure resistance, making sealing fiberglass flanges difficult. Gore solved this problem with its patented expanded polytetrafluoroethylene (ePTFE) gasket, specifically designed to seal flanges at low stresses. This solution was successfully demonstrated in a multistage testing procedure conducted in cooperation with a globally leading manufacturer of anti-corrosive fiberglass pipe systems. Continue reading GORE Universal Pipe Gaskets Have Great Success in Aggressive Media Applications→
So you spend hundreds or even thousands of dollars every year on sealing solutions, like gaskets. But did you know that the way you store your gaskets could affect the effectiveness or life span of your gaskets? In this blog, we offer some tips for gasket storage and shelf life which, if followed, can help ensure that your gaskets are always ready for service.
Gasket Storage and Shelf Life: General Storage Principles
Rubber gaskets should always be stored in a cool location which is free from excessive humidity, direct sunlight, and the presence of chemical vapours or fumes. The storage location should ideally be indoors and free from exposure to the elements or inclement weather. If the storage guidelines given below are followed, rubber gaskets or gasketed components have the following expected shelf life:
Tips for Gasket Storage and Shelf Life
Tip #1: Limit exposure to light
Sunlight and strong artificial light can degrade some gasket materials. For this reason, rubber gaskets should be stored in cartons or opaque bags which prevent direct exposure to light.
Tip #2: Maintain relative humidity levels
Very moist or excessively dry conditions in a storage location should be avoided. Relative humidity levels below 75% are recommended for most rubber gaskets. Similarly, very low humidity levels which can cause some materials to dry out and become brittle should also be avoided. Continue reading Tips for Gasket Storage and Maximizing Life→
Under pressure? Absolutely. The increasingly high temperatures and harsh conditions to which gaskets are exposed makes selecting the right gasket all the more important.
In industries such as chemical processing, hydrocarbon refining, and power generation, leakage from extreme temperature process streams can result in loss of efficiency and production as well as adverse environmental impacts and compromised employee safety. One of the most commonly used sealing products in systems subject to high pressures and temperatures is a spiral-wound gasket. These gaskets typically consist of filler and winding materials selected on the basis of application requirements and end-user preference. Proper selection of these materials is critical to achieving the desired performance in all applications.
Sealing at temperatures above 850 ºF (454 ºC) is particularly challenging because of the limited number of filler materials that can resist thermal degradation at extreme temperatures – these temperatures affect both the sealing material and metal components. For instance, the yield strength of fasteners decreases as the temperature is increased. In addition certain chemicals can become more volatile and aggressive in high-temperature reaction processes.
The two most common filler materials in spiral-wound gaskets are graphite (can withstand temperatures up to 850 ºF) and polytetrafluoroethylene (PTFE; tolerance up to 500 ºF). Other filler materials are used mainly for their thermal insulating properties, not for sealability; these include mica, exfoliated mica, and ceramics. While graphite and PTFE perform satisfactorily in terms of temperature and chemical resistance, they have limitations. Graphite is not compatible with heavily oxidizing media at any temperature, nor can it withstand continuous operating temperatures above 850 ºF. Beyond 850 ºF, volume loss through oxidation becomes excessive and sealing effectiveness is compromised.
Many high-temperature systems, such as exhaust manifolds and flanged piping connections in exhaust systems, are oxidizing. Other services are oxidizing because of the operating temperature and media involved. Continue reading Gaskets Designed to Take the Heat→
The Garlock Family of Companies has launched a new fully-coated isolation gasket known as EVOLUTION.
EVOLUTION® Isolation Gaskets
The next generation of isolation gaskets, EVOLUTION®, features easier installation, tight sealing, high-temperature operation, no permeation, hydrotesting isolation, fire-safety and chemical-resistance.
Featuring a thinner, 1/8-inch design, EVOLUTION minimizes the difficulties encountered when attempting to install thicker isolating gaskets. The full-coating encapsulation allows the gasket to be hydrotested and left in the pipeline with the same isolation properties as before it was tested.
EVOLUTION’s coating is highly resistant to abrasion and impact while providing chemical resistance to hydrogen sulphide (H2S), steam, carbon monoxide, carbon dioxide and other chemicals often found in oil and gas pipelines. This fully encapsulated coating also prevents the need for expensive exotic cores, as it eliminates contact to exposed metal. Continue reading Garlock’s New Isolation Gasket: The Future of Flange Isolation→
How the raised surface profile of PTFE sheet gasket helped a midstream oil and gas processor address leaky pipes
Bolted flange-gasket connections in process piping systems are common and given little thought – unless they start to leak.
Chronic leakage proved to be an issue for one of Garlock’s clients, a midstream oil and gas processor and services provider. The site processes, stores, and transports natural gas, liquefied natural gas and petroleum products. Garlock was brought in to provide a solution to the problem.
Successful connections are dependent on a variety of things, including the state of the flange surfaces, alignment, bolt and nut grade and strength, bolt and nut thread condition, lubrication, bolt tightening process, service conditions, and choice of gasket.
When a flange-gasket joint is assembled, the gasket must first be compressed to fill the gaps between the flange surfaces, creating a seal when system pressure is applied. Secondly, it must maintain that seal as the system is brought on-line and temperature and pressure escalate.
As the temperature increases, a gasket made of non-metallic materials such as rubber, fibre, PTFE and inorganic fillers is prone to lose thickness, that is, creep. And the thicker the gasket is, the
more it is prone to creep (1/8-inch thick gaskets creep more than 1/16-inch).
The two most important performance qualities of a gasket are its ability to seal and its ability maintain that seal. These can be indicated by industry standard tests for sealability and creep.
On the surface, this particular case study would seem to be an application of little complexity. However, the details of the joint gave rise to several issues that caused the user chronic leakage problems. Here are the service conditions and background of this particular case:
Temperature: 100°F to 120°F (38°C to 49°C)
Flanges and use: 18-inch Class 150 raised face flanges used in the pipe systems of cooling tower water pumps. Multiple gaskets are on either side of spool piece
Pressure: 100 psig to 150 psig (7 bar-g to 10.3 bar-g)
The American Society for Testing and Materials (ASTM) International Committee F03 on Gaskets recently released the latest standard practice to derive gasket design constants for the proper design of bolted flanged joints (BFJs): ASTM F2836-18. End users of gaskets can then use these gasket constants for proper BFJ design using calculation methods that are currently being developed by a special working group of American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) Section VIII at the time of this publication. In this article, the current test procedure, the mathematical models of the test evaluation and the calculation of the characteristics are described and discussed.
Most industry professionals are aware that BFJs used in fluid service are complex mechanical systems. In order to create a high-performing BFJ, a designer needs to carefully consider not only the service conditions the BFJ will encounter, but also the performance characteristics inherent to the components of the BFJ. The gasket itself is one of these critical, yet often overlooked, components, and efforts to determine and quantify the performance characteristics of gaskets have been ongoing for decades.
The newest of these efforts to be published in the United States is ASTM F2836-18: Standard Practice for Gasket Constants for Bolted Joint Design (commonly referred to as the Room Temperature Tightness Test, or ROTT). The design constants produced by this method enable a more robust design of BFJs compared to previous, antiquated design constants, such as the m and y factors.
The crucial gasket constants produced by this standard practice are a, Gb and Gs. These constants effectively describe the tightness behavior of the gasket material, reflective of different loading and service conditions.
In addition to their application to the ASME calculation method currently under development, the constants can also be used to compare materials so the proper one may be selected for the application.
Who Will Use ASTM F2836-18?
ASTM F2836-18 is a helium leakage testing and evaluation method that determines tightness-based design constants at room temperature for pressurized bolted flange connections that are designed in accordance with ASME BPVC. As such, ROTT applies mainly to all types of circular gasket products—including, but not limited to, sheet-type, spiral wound, solid metal and jacketed gaskets.
As such, these constants stand to be of interest to all parties who work with circular gaskets and have a vested interest in producing a high-performing BFJ, including end users, BFJ assembly contractors and gasket manufacturers.
The test method consists of analyzing data from multiple gasket leakage tests in order to calculate the three aforementioned design constants for a particular model and size of gasket. The testing can be performed in a pair of appropriately sized flanges, using bolts to achieve varying gasket loads, or in a servo-hydraulic test stand of adequate capacity (Image 1).
In total, the procedure consists of two high-pressure (HP) tests at 6 megapascal (MPa) (870 pounds per square inch [psi]) of helium and two low-pressure (LP) tests at 2 MPa (290 psi) of helium, for a total of four tests on four different specimens. In addition to the differences in internal pressure, the HP and LP tests are also distinct from each other in terms of the gasket loading sequences.
The HP test consists of loading and unloading sequences, continually introducing successively higher loads onto the gasket while interrupting this loading sequence with intermittent unloading ramps. The LP test consists of only a loading sequence.
In both tests, the helium leak rate is measured at these various gasket loads.
For the purposes of test evaluation and gasket constant derivation, the different loading sequences of the tests are categorized as either Part A or Part B. Part A consists of the loading sequences, while Part B consists of the unloading sequences. Therefore, the HP test contains both Part A and Part B sequences, while the LP test consists of Part A only.
See Image 2 and Image 3 for details of the HP and LP testing sequences, respectively.
With its increasing gasket loads, Part A simulates assembly of the gasket in the joint, and therefore represents the gasket seating process. The data from this portion of the test is used to determine the required seating load for the gasket to create a tight seal.
Part B simulates the operating conditions by unloading the specimen to different gasket stress levels. This replicates unloading of the gasket, seen in real applications, due to various factors including internal pressure and relaxation effects of a gasket during operation. Part B test data is used to determine the required operating gasket load in order to maintain a tight seal. Continue reading ASTM International Committee Releases Latest Room Temperature Tightness Test→
GYLON EPIX® is a family of gaskets that effectively seals a broader range of applications and is more forgiving during the installation process. It allows the end user to save valuable turn-around time, reduce re-work, and lower costs, helping them to finish ahead of schedule and under budget.
GYLON EPIX® features a hexagonal surface profile that provides the torque retention and blowout resistance of a thin gasket and the conformability of a thicker gasket. GYLON EPIX Style 3504 is a high performance, aluminosilicate microsphere filled PTFE sheet material designed for use in moderate concentrations of acids, and caustics, as well as hydrocarbons, refrigerants, and more.
Chemical Manufacturer and Distributor
Loading stations are very critical in the chemical industry as flanges are disassembled and reassembled everyday.
Due to the dangerous media being transported through the flanges there is a high risk of incidents and human harm, making it necessary for the gaskets to only be used once. For this reason the customer was looking to evaluate a solution that was more adaptable than the current gaskets being used.
Temperature – Ambient outdoor temperature
Application – Flange connections at the load/unload station (4 stations). Flanges EN1092-1 Type 01, PN10-40, 316 TI stainless steel
Media – Sulfuric Acid (Oleum) with a concentration of 94%
Pressure – 2 bar/29 psig
SOLUTION AND BENEFITS
GYLON EPIX 3504 PTFE gasket with Aluminosilicate Microspheres is specifically designed for use in applications where many acids and caustics are present, making it the ideal solution in the loading stations. GYLON EPIX 3504 performed exceptionally during the 110 day evaulation allowing the customer to continue use with confidence.
Gallagher is your source for all of your Garlock sealing needs. If you have further questions regarding the GYLON EPIX™ 3504 EPX, or any other Garlock products, please do not hesitate to contact us. Our engineering department is always ready to help you design a sealing solution to your toughest application!
Created more than 40 years ago, Gore Joint Sealant was the first form-in-place gasket. It was and still is a great sealing solution for steel flanges with large diameters, irregular shapes, or rough/pitted surfaces. It forms a thin yet strong seal when compressed and works in applications where bolt loads are low.
With a reliable, easy install and being a cost-effective sealing method, it’s become standard seal for MRO applications all over the world. Installing it is very easy, too: Simply peel off the adhesive backing, apply it to the flange, and overlap the ends. Voila, you have an immediate custom gasket for your unique flange shape.
Looking at Gore Joint Sealant, you may notice it looks strikingly similar to other Gore products, such as Gore 500 Series or Gore 1000. So, what makes them different, and what is the right choice for your application?
The Difference Between Gore Joint Sealant and Gore Gasket Tape Series 500
Simply put, the main decision factor for customers looking at Gore Gasket Tape products vs Joint Sealant is thermal performance. Gasket Tape Series 500 Tape has a much more expansive thermal range.
Gore Joint Sealant’s operating range is for temperatures between -60°C to 150°C (-76°F to 300°F).
Gore Gasket Tape Series 500 has a typical operating range between -60°C to 230°C (-76°F to 445°F).
It also has a maximum use from -269°C to 315°C (-452°F to 600°F).
Both products have excellent chemical resistance to all media pH 0-14 except molten alkali metals and elemental fluorine.
Joint sealant’s strength is derived from its fibers, not nodes. It’s made from 100% expanded PTFE with a monodirectional strength. Gasket Tape Series 500 is also made of 100% ePTFE but has multidirectional strength, making it less “squishy,” but much stronger.
For many applications, Joint Sealant would work just fine. For example, the Pulp & Paper industry generally works really well for Joint Sealant applications. There’s no need for Series 500 in their flanges due to the nature of processing at the facility. However, more demanding applications typically use the Series 500 or even Series 1000 Tape.
Speaking of Gore Gasket Tape Series 1000, what makes it different than the other two?
The Difference Between Gore Gasket Tape Series 500 and Gore Gasket Tape Series 1000
Gore Gasket Tape Series 1000 is a sealant that is excellent for particularly challenging applications, such as glass-lined steel equipment. Typical users of this product are chemical processors who deal with aggressive media under demanding conditions. These types of applications frequently have challenging and varying conditions – high temperatures, alternating pressures, low gasket loads, or deviations in surfaces. The main thing that differentiates Gore Series 1000 Tape from Gore Series 500 is the proprietary barrier core. This core helps to maintain the seal even at very low loads.
Gore’s Gasket Tape Series 1000 has an engineered core to amplify the available load. This helps create a seal more than 10X tighter than other ePTFE gasket tapes. Because of this, it delivers exceptional sealing reliability over time and process cycles relative to other ePTFE gasket tapes. It allows for more uptime and runtime periods, enabling longer maintenance cycles.
No matter the type of process media – – Gore has a solution to help you quickly seal challenging applications.
Still not sure which Gore product might be right for you? Check out this simple flow chart to see which one is best for you:
Gallagher Fluid Seals is an authorized distributor of Gore products, which include Joint Sealant, Gasket Tapes, UPG gaskets, and more. For more information or to see if Gore might be a good fit for you, contact us today.
Bacteria accumulation can ruin product and put consumer health at risk.
Bacteria accumulation is a serious issue in the food manufacturing industry – it can ruin product and put consumer health at risk.
While many know that Polytetrafluoroethylene (PTFE) is an excellent choice for use in diaphragms and gaskets, most do not realize that there exist varying grades of PTFE. Some lower cost PTFE offerings may contain an excessive volume of pores within their structure which can harbor organic contaminants such as bacteria.
To address this problem, a calendared manufacturing process is used. Calendared PTFE is a premium grade PTFE designed for use in aseptic applications requiring ultra-high purity standards. It is ideal for use in food, pharmaceuticals and a variety of clean markets.
Distinguished by an extremely low void content, calendared PTFE resists permeation and the accumulation of foreign matter, reducing the risk of harboring unwanted bacteria or residual media.
To achieve this, the unique manufacturing process orients the chains of PTFE in a lattice-like structure that reduces voids in the material and provides it with biaxial strength. This unique structure also delivers a very high flex life. When tested in an MIT Folding Endurance Tester, the flex life of calendared PTFE is four-times greater than conventional PTFE materials.
Unlike the skived process that is commonly used for PTFE manufacturing, the calendaring process produces uniform sheets of material with consistent physical properties. This gives calendared PTFE a renowned reputation for predictable performance and quality. The opposite is true for skived PTFE where variable properties lead to varying performance and reliability.
Gylon Epix’s patterned material provides enhanced compressibility for better sealing
Gaskets are ubiquitous components in a processing plant. Every flange, equipment joint and connection point will have some form of gasket to prevent fluids from compromising (i.e., leaking from) a process system. However, effective sealing can pose challenges. A new form of polytetrafluoroethylene (PTFE) gasket, Gylon Epix, already has successfully addressed a number of persistent problems at plants.
The gasket, which is available in 3⁄32-in.-thick, 60-in. × 60-in. sheets, features a raised hexagonal pattern (Figure 1). It exhibits enhanced compressibility over both 1⁄16-in. and 1⁄8-in. traditional gaskets, seals easily when compressed by flanges and maintains assembled bolt torque better than comparable 1⁄8-in. PTFE gasket materials.
Successes with Gylon 3501-E and Gylon 3504
Trials at three early adopters of the new material underscore its value.
Fatty acid production. A German manufacturer of oleo-based chemicals, including fatty acids, glycerin, fatty alcohols and fatty esters used in consumer and personal health products, was experiencing problems sealing a 29.3-in. (745-mm) outside-diameter spiral heat exchanger. A gasket located atop the heat exchanger was exposed to polysaturated fatty acid and coolant at a continuous temperature of 428°F (220°C) and pressure of 87 psig (6 bar). J-type clamp bolts fasten the lid to the heat exchanger. Spiral heat exchangers present challenges because the gasket must seal across the entire face of the lid, requiring a gasket that will efficiently transmit the force from the bolts across its entire surface.
The traditional PTFE sheet gasket was allowing leakage across the exchanger’s spiral passes, decreasing efficiency. The gasket exhibited cuts from the spiral separation bars and required frequent changes that disrupted manufacturing and decreased plant productivity.
Gylon Epix 3501-E was installed in December 2017 and, after six months of testing, concluded it sealed well. Upon disassembly in July 2018, it was found to be in good condition, with no traces of cuts, discoloration, brittleness or sticking to the lid (Figure 2). A new gasket was installed in July 2018, which now has completed a successful one-year trial; the gasket continues to perform well.
Phosphate processing. New or refurbished equipment generally seals bolted connections well. As the equipment ages, gaskets and flange surfaces help seal gaps caused by corroded, worn, misaligned or repositioned equipment flanges. At a Mexican acid processor, Class 150, 8-in. raised-face flanges of the inlets and discharges of phosphoric and sulfuric acid transfer pumps had become worn and corroded. Temperatures were 104°F (40°C) and pressures 57 psig (4 bar). The 1⁄8-in.-thick glass-filled PTFE gaskets didn’t consistently provide a tight seal. So, the plant applied mastic filler to treat damaged flange surfaces as a stop-gap measure.
Gylon Epix 3504 was installed in December of 2017; it performed successfully without the need for flange treatments or special installation handling. Its enhanced compressibility fills the gap of imperfect flanges. It performed well until its removal in September of 2018 when the pump mechanically failed for a reason not related to the gasket. The acid processor is adding Gylon Epix to its approved materials list because it worked without the need for mastic, was flexible and easy to handle, and performed with zero leaks.
Terephthalic acid manufacturing. A southeastern U.S. producer of terphthalic acid (TPA) was experiencing leaks with traditional glass-filled PTFE sheet gaskets on a pressure vessel operating at 230°F and 60 psig that has a 60-in. × 10-in. rectangular gasket joint opening. Large rectangular joints can have uneven surfaces due to warpage of the cover. In July of 2018, Gylon Epix 3504 was installed and is still in service as of September 2019 and performing well. The company has accepted the product into its system and is re-ordering.
The original article can be found here and was written by Jim Grago, PE, a principal applications engineer for Garlock.
Gallagher Fluid Seals is an authorized distributor of Garlock. For questions about products or to see if Gylon Epix is the right fit for your application, contact our engineering department.