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About Select-a-Seal® Rubber-Edged Composite (REC) Technology
Q: In what ways are Select-a-Seal® gaskets different from other gaskets?
A: The Select-a-Seal brand name denotes a completely new category of sealing products – rubber-edged composites (RECs) – the only kind of sealing system in the marketplace that uses a compressible, non-rigid composite base (or carrier) in combination with a rubber (polymer) sealing edge. In most cases, the edge polymer provides adhesion that enhances the sealing mechanism.
Q: How does a Select-a-Seal REC gasket differ in performance from other sealing barriers?
A: In a typical joint that uses a static rubber (polymer) seal as a sealing barrier, there is a maximum limit on the amount of compression that can be applied to the rubber. So, when the seal relaxes over time, leaks can develop. The dynamics within a Select-a-Seal REC joint are very different from those in a typical "fixed compression" joint. With Select-a-Seal REC seals, as the rubber sealing edge relaxes over time, the compressible carrier further compresses and transfers "new" compressive stress to the rubber edge-seal. The result is higher retained sealing stress within the joint.
Q: Compared to manufacturing processes for other sealing technologies, what advantages are inherent in the way Select-a-Seal REC gaskets are made?
A: Interface Solutions employs a unique, patented manufacturing process in a new QS-registered facility, where products meet the highest standards of quality control. Compared to manufacturing processes for some other sealing technologies, the Select-a-Seal production process does not require the costly, time-consuming creation of dies or tooling. For example, in round figures, the production tooling cost for a Select-a-Seal REC gasket is about $5,000 compared to as much as $40,000 for a rubber-on-metal product and $100,000 for a rubber-edged-metal system. Other competitive advantages result because Select-a-Seal REC gaskets are processed in large quantities, and polymers are applied to the edges of gasket apertures by coating rather than molding. A gasket with more than one sealing aperture can be coated with a different sealing polymer on each aperture – up to three kinds of polymer on one gasket – allowing one gasket to provide optimum sealing against a variety of fluids.
Q: What strategies are open to Interface Solutions' engineers to allow them to customize Select-a-Seal RECs for specific applications?
A: Besides being able to apply as many as three different polymers to the same gasket, Interface Solutions' REC approach to sealing provides additional freedom to engineers to design seals for specific applications. Since different applications have different features (flange stiffness, bolt loading, internal pressure, etc.), demands on the base carrier differ from application to application. Select-a-Seal applications engineers analyze the stresses in each joint and choose the base carrier with the optimum combination of cost and physical properties (compression, tensile strength, surface friction, etc.)
Q: How quickly can Interface Solutions respond to a request for a prototype for a specific application?
A: Because of the efficient design and production processes available for the creation of Select-a-Seal REC products, the turnaround time for a Select-a- Seal prototype is about 10 days following the receipt or creation of a CAD file of the flanges to be mated. Because of the comparatively long times required to create dies or other tooling for competitive technologies, the design lead times for rubber coated metals is about 60 days while the lead time for rubber-edged metals is around 120 days.
Q: What are some considerations in varying the rubber (polymer) edge for specific applications?
A: On a Select-a-Seal REC gasket, customizing edge properties includes controlling the adhesive properties, thermal properties, and compression characteristics of the edge polymer. In other sealing technologies that use rubber, e.g., O-rings or rubber-edged metal gaskets, the polymers are relatively hard and have almost no adhesion characteristics. Due to their rigidity, these products do develop high initial sealing stress, but they rely on stress retention for seal integrity over time. By contrast, Select-a-Seal REC gaskets generally employ custom-formulated polyacrylic edge-seals with adhesion properties. They develop a lower initial compression stress compared to the typical O-ring seal, but over time they retain stress better. By varying the formulation and treatment of edge polymers, Interface Solutions' engineers can vary the adhesion characteristics and compression stress as well as resistance to extremes of hot and cold, as well as resistance to a variety of fluids.
Q: What are some considerations in varying the base (carrier) for specific applications?
A: Since requirements such as flange stiffness, bolt loading and internal pressure vary from application to application, Select-a-Seal applications engineers examine the specific characteristics of a joint while choosing a base carrier. For example, a carrier can be selected that optimizes the required physical properties (compression, tensile strength, surface friction, etc.) while taking into consideration specific conditions that the joint may experience (shear forces, low temperatures, etc.). It's easier to vary the mechanical characteristics of Select-a-Seal base composites than it is to vary the bases of other kinds of gaskets, because in an REC gasket, the edge, not the carrier, forms the seal.
Q: What have been some typical successful applications of Select-a- Seal REC technology?
A: Select-a-Seal REC technology has experienced considerable success in applications on heavy-duty diesel engines and power transmission designs for power takeoffs and accessory drive covers. Other successful applications, which underscore Select-a-Seal REC gaskets' abilities to handle a variety of fluids, include water pumps and automotive applications as diverse as axle covers, fuel pumps and oil pans. More important than specific industries served, however, is the fact that Select-a-Seal RECs exhibit durability – the measure of how long a product seals without leaking under certain test conditions – in combination with outstanding robustness – the measure of a seal's ability to perform acceptably in less than ideal circumstances, e.g., when a flange bolt is missing. In fact, tests indicate that Select-a-Seal REC technology should be considered in applications with lessthan- ideal bolt positions, including wide bolt spans, as well as conditions of low loading, rough or unmachined flange surfaces, highly dynamic joints and highly loaded joints, among others.
Q: Will Interface Solutions work with our company to develop the best seal for an application?
A: Interface Solutions is capable of side-by-side comparison tests under identical conditions on a Select-a-Seal REC gasket developed for one of your most difficult applications and the gasket you currently use in that application. Interface Solutions has run many such tests on the gasket technologies against which Select-a-Seal typically competes, and our customers have benefited. In these tests, technicians vary clamping forces on the gaskets and internal pressures. They also vary the surface finishes and the type of metal (or metals) of mating flanges, the results indicate which products are appropriate for specific conditions. As a result of all this testing, there are now many applications for which Interface Solutions' engineers can immediately propose a solution. In such cases, the engineers can say with confidence that if the geometry of an application allows, the application is workable because the testing has been done. However, if a particular application is untested, InterFace Solutions might opt for testing it as a way to increase its knowledge and understanding of sealing needs across a broad range of industries.
Q: Who can I contact in order to get more information about Select-a- Seal REC gaskets?
A: For help with technical or customer service questions, click on "Rep Link" and pick the appropriate ISI representative from our list of worldwide personnel.