Composite pneumatics seals

Pneumatic seals are a device that restricts the escape of air or the entrance of foreign materials in a pneumatic application such as a cylinder. Pneumatic Seals are designed for low operating pressure. Pneumatic Seals are vital in machinery. Pneumatic Seals may be used for rotary and reciprocating motion. Pneumatic cylinders typically demand higher operating speeds and lower friction pneumatic seals. Common pneumatic seals include rod seals, piston seals, symmetrical seals, V-Rings, wipers, rotary shaft seals, wear rings, static seals, back-up rings, o-rings, buffer rings, u-cups and gaskets. Pneumatic seals can either be single or double acting. Single acting pneumatic seals are used for one axial direction only. Double acting pneumatic seals are used in both directions for a reciprocating motion. Pneumatic seals require minimal lubrication when exposed to air in order to create a tight seal.

Pneumatic seals may also be exposed to high operating speeds at which the pressure is not high. Piston seals, rod seals, flange packings, u-cups, and vee-cups are a few sealing designs that take advantage of pneumatic seals. The difference between pneumatic seals and hydraulic seals is pressure. Pneumatic seals typically have a pressure range of 1 to 150 pound-force per square inch (psi), while hydraulic pressure can reach greater than 10,000 psi. Pneumatic seals can be made of a variety of materials like Polyurethane, Nitrile, Viton, Silicone, EPDM and some types of PTFE. A pneumatic seal's sealing orientation can be internal as with a rod seal, external as with a piston, symmetrical, or axial. With internal pneumatic seals, a housing bore surrounds the seal and the sealing lip touches the shaft. This seal requires very little lubricant. With external piston pneumatic seals, the seal surrounds a shaft and the sealing lip touches the housing bore. This system requires more lubrication. Symmetric pneumatic seals are the same on both sides, and axial pneumatic seals fit axially against the housing. In both cases, however, the seals are used externally and require more lubrication.

Sometimes, composite seals are used as pneumatic seals. Composite seals are seals composed of two or three different materials. Therefore, pneumatic seals are often found in products requiring one seal for many parts. A PTFE ring and an elastomer ring are often used in this situation. NASA uses this technology in their rocket systems. Composite pneumatic seals are also used in the diesel engines for trucks. Rotary applications need only one pneumatic seal. This seal is considered to be single acting because it can seal in one axial direction while the application is moving. On the other hand, a reciprocating application requires two pneumatic seals, or double acting seals. In this case, one seal is needed for each of the directions. Double acting pneumatic seals are more complicated than single acting ones. 
 
Darcoid Nor-Cal Seals is an ace supplier of sealing solutions and accessories. Darcoid supplies a number of seals, wear rings and scrapers / wipers specifically engineered for pneumatic applications, where cylinders and valves are actuated by air. Pneumatic seals operate in dynamic applications, often at high speeds, generally with rotary or reciprocating motions. 

 

Standard sized fluid power seals

Seals have been used since ancient times and have evolved into a wide variety of shapes and materials. For those who are not familiar with sealing technology, the number of options available can be confusing. Selecting the most suitable product for a given application can be difficult. This engineering section will assist in product selection by explaining the fundamentals of seal design and material technology.

Darcoid Nor-Cal Seal is a leading distributor of fluid power seals. Darcoid Nor-Cal Seal has been providing standard and custom-made fluid power seals for a wide range of applications and industries for a long time as an industrial global leader and has been providing fluid power seals for various applications including Aerospace and Military markets where quality is of utmost importance. A fluid power seal is a two piece design consisted of standard sized rubber square ring energizing a PTFE cap.

Fluid power seals are widely used in heavy duty hydraulic actuators. Darcoid Nor-Cal Seals deliver top quality fluid power seals that are of excellent quality, stability, long lasting, low friction and give protection from extrusion. The applications that use fluid power seals include agriculture hydraulics, mobile hydraulics, machine tools and hydraulic presses. Darcoid is a global leader for diversified products of motion and control technologies and systems. The company provides precision engineered solutions for a wide range of commercial, mobile, industrial and aerospace markets.

When choosing a sealing system, the desired result is ultimately leakage control. Seal design and material improvements have made it possible not only to have seal combinations that provide zero leakage, but also provide extended life in a variety of applications. Aside from the seals themselves, a thorough understanding of system parameters is necessary to obtain the best results. Optimal sealing is best achieved by taking a system's approach to the seal package rather than considering components individually.

Fluid power seals from Darcoid Nor-Cal Seals have been designed specifically to compliment one another to create high performance systems. For instance, pairing a Darcoid's rod seal with a wiper minimizes fluid leakage and maximizes contamination exclusion. The seal element plays a vital role in the hydraulic system. It can prevent the fluid leakage and also can stop the outside air or dust entering into the system. The hydraulic seal elements are the core of the hydraulic equipment. For a hydraulic device to perform better, a good hydraulic seal is necessary, which is the guarantee of the excellent hydraulic device.

Therefore, this device has been widely applied in a lot of sectors, such as industry, agriculture and nation defense. In order to ensure the good performance of the hydraulic transmission device, the hydraulic seal must be compatible with the features of the device. The leakage rate of the hydraulic seal must be very small. With the increase of the hydraulic liquid's pressure, the seal intensity can be improved automatically.

Even though the seal is used in the harsh environment, the leakage rate can not be increased obviously. The seal is often soaked in the fluid and so it easily becomes hard. In order to ensure the long-term sustainability of the seal, the hydraulic seal should be compatible with the liquid. The hydraulic seal must be characterized by features, such as heat, pressure and abrasion resistance and also good elasticity. Technological innovations and valued added services allow us to engineer your success with leading edge material development, experienced design and application engineering, quality and outstanding customer service.

EMI gaskets variations

            

                The primary goal of an EMI shielding gasket is to seal an electronic enclosure to prevent transmission of electromagnetic interference. Improper design of the seal or enclosure mating flanges can result in a failure. Several mechanical design issues must be considered for the proper mating of an EMI gasket with the flanges of an electronic enclosure. Determining the effectiveness of a system overall EMI shielding needs involves understanding the radiated emission spectrum of the equipment, and the specifications the unit must meet. Various EMI shielding gasket types provide different levels of shielding effectiveness across the frequency range of 10 kHz to 20 GHz, such as the Soft-Shield 5000 materials.

Many EMI gasket variations provide a 'best fit' for different operating environmental conditions. Exposure to high and low temperatures, wind and rain, salt spray, solvents used in cleaning and plating, and other conditions severely affect the life of an EMI shielding gasket. EMI gaskets require some amount of compressive force to function properly.As a result of this load, the material will decrease in height (deflect).Many commercial-grade gaskets must deflect 30-40% under low closure forces to properly maintain contact with mating flanges.

Gasket material subjected to compressive forces for an extended time causes 'deflection' to remain when the load is removed. Compression set is an important property in designs where the EMI gasket will be compressed and released regularly while in service in enclosure doors and access panels. EMI shielding gaskets provide conductive pathways that electrically bond system components to a common ground. The gaskets serve as low impedance conductors to ensure the reliability of an enclosure.

The method of installing an EMI shielding gasket can be a major factor in determining shielding costs. Gaskets can be installed using pressure-sensitive adhesives, fasteners, or epoxies, or by press-fitting into grooves. Some gaskets are molded in place on the enclosure flange or on a plastic spacer frame. Be it for various purposes in aerospace, automotive electronics, computers, data communications, general electronics, medical equipment, military, network equipment or telecommunications, Darcoid Nor-Cal Seals provides electromagnetic interference shielding gaskets and seals to more high-tech industries in more places around the world than any other EMI specialist. Darcoid Nor-Cal Seal is a world renowned manufacturer of sealing solutions and a wide range of accessories like die cut gaskets and spliced o-rings, and a distributor for the top manufacturers of seals, gaskets and rubber products.

Darcoid Nor-Cal Seal, an endeavor that specializes in supplying all kinds of sealing solutions, offers a broad range of products in Electro Magnetic Interference shielding applications like EMI shielded gaskets and seals. These products work by containing or excluding electromagnetic energy in RF modules and components, waveguides and structural enclosures.

Darcoid Nor-Cal Seal is into supplying world class EMI shielding Gaskets and Seals, O-Rings, Molded Rubber Parts, EMI/RFI Shielding products like Adhesives, Sealants, Conductive Compounds, Conductive Elastomer Gaskets, Conductive Tapes and laminates, Conductive Grounding Tabs, Metal EMI products, Parker O-Rings & D-Rings, Shielded Windows, Shielded EMI Vents, Thermal Grease & Gap fillers, Wave Guides, Wire Mesh Gaskets and many more.

The Electro Magnetic Interference shielded gaskets and seals come in a wide range with their volume resistance in order to achieve the desired shielding effectiveness. Products are available as non-hardening caulking compounds, silicone or vinyl based sheets as well as conductive adhesives and coatings. Darcoid is an expert in supply chain management and value added distribution services, resulting in high quality seals and good cost value solution for your company.