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.

Distinct advantage over homogeneous diaphragms

Fabric reinforced diaphragms utilize a layer of an engineered fabric material as part of the diaphragm construction. This layer of fabric give tremendous design flexibility. A very thin-walled diaphragm can withstand high pressures while remaining very flexible and responsive to minor pressure variations. A fabric reinforced diaphragm limits the stroke and provides a frictionless seal. These diaphragms generally cost less, have more tolerance range, and do not require hardened super finishes or lubrication. The function of a diaphragm is the most important factor in its design and manufacture. Simple diaphragms move from one position to another, such as pressure switches and solenoid valves. Diaphragms can be used as shock absorbers as in a dash pot or as dampening devices in pulsating systems. Diaphragms can also be used as barriers between fluids and gases, such as in a pressure drop on the fluid side.


Fabrid reinforced diaphragms are used in pumps, such as automobile fuel pumps, hand pumps, and diaphragm air compressors. In these cases an outside mechanical force is actuating the diaphragm. This functions to displace a volume of media. In the case of a pump the diaphragm creates a low pressure area causing the fluid or gas to move into this area. In all the above cases the function of the diaphragm will generally be the determining factor when considering the type of construction, the material composition, fabric design (weave/knit), and the type of polymer.


Supported diaphragms are produced from a wide variety of fabric, varying strength, weights, and weaves. The fabrics themselves range from natural fibers, such as silk and cotton to the man-made fibers and high strength arimids. The elastomeric coatings can be put on both sides of the fabric in equal thickness or an unbalanced coating. Many applications require elastomeric coatings on only one side such as applications where the pressure differential is in one direction. When knit fabrics are employed, the coating is usually on one side and the same side as the pressure. This allows the fabric to support the coating on both sides for flat diaphragms.


The selection of the fabric substrate, in terms of strength, weight and flex life will greatly depend on the application. Fabric reinforced diaphragms have a distinct advantage over homogeneous diaphragms. Supported diaphragms have less tendency to stretch under pressure conditions. Most importantly, fabric substrate takes all of the stress from the rubber leaving the rubber to work in the least stress conditions.


Darcoid Nor-Cal Seal offers a wide range of elastomer compounds including NBR, EPDM, neoprene, epichlorohydrin, silicone, fluorosilicone and fluorocarbon, as well as polyester, nylon, high temperature nylon and silk fabric reinforcements. Fabric reinforced diaphragm seals are an ideal solution where accurate, consistent response is required for changes in hydraulic or pneumatic pressures, maintaining zero leakage, and offering almost zero friction without the need for lubrication. Darcoid Nor-Cal Seal supplies fabric reinforced diaphragms for usage in applications in many industries including automotive, aerospace, semiconductor, medical, instrumentation and process control industries, they offer an inexpensive solution to design problems.

The uniqueness of lip seals

              A lip seal is a rotary seal incorporating a deflected lip seal geometry. Anti-rotational devices such as flanges and O-rings are often utilized to prevent the seal from rotating with the shaft. Standard and custom sizes are available with a wide selection of PTFE materials. Lip seals are suitable for sealing corrosive and abrasive media. A wide range of geometries and materials are available, depending on specific application requirements. Lip seals are often used on motors and compressors and other components with high speed rotary shafts due to their ability to resist wear even while pressurized.

The most common lip shape is the chamfered or back-beveled design and is available with the V and C Series spring types. This design allows for ease of installation and permits lubrication to nest under the lip and feed through in reciprocating dynamic applications. The result is a microscopic film of lubrication that increases seal and hardware service life. Since the footprint (contact point) of a chamfered lip is a single point, all of the sealing force is concentrated on that point, yielding the highest sustainability and lowest friction.

Applications often involve medias with abrasive particles that can get caught between the seal lip and the mating hardware. This increases wear to both the seal and the mating surface. To prevent particles from accumulating, the scraper lip design is available with all three spring types. The scraper lip contact point is positioned directly over the load point of the spring in each design for maximum scraping action. The scraper lip can be positioned on the ID, OD or both. The scraper lip also stays in place better in a stepped gland where the step is not very large.

The beaded shape contacts the surface in much the same way as an O rings, and is available with the V and H Series spring types. Similar to the chamfered lip, it is easy to install and helps to lubricate the reciprocating sealing surface. In fact, the beaded lip yields a film of oil that is slightly thicker than that of a chamfered lip, making it advantageous for applications with rapid reciprocating motion. Darcoid Nor-Cal Seal is an excellent supplier of lip seals.

Darcoid Nor-Cal Seal provides sealing solutions which are highly cost effective, have high production rate sourcing to the highest technologies. A single lip seal can play an important role in two directions' seal and is applicable for different seal media such as oil, water, gas, chemical medium and other mixed media. The uniqueness of these lip seals from the house of Darcoid Nor-Cal Seals makes the product reliable and sustainable.

Darcoid Nor-Cal Seal is a leading distributor of hydraulic seals. Darcoid Nor-Cal Seal has been providing standard and custom-made lip seals for a wide range of applications and industries for a long time as an industry leader and has been providing Hydraulic Seals for the Aerospace and Military markets where quality is of utmost importance.

High quality supporting accessories for your high-end machinery

Darcoid specializes in rendering rubber products, machinery supportive accessories and adhesives, Parker seals for flawless functioning of your machinery. Darcoid paves into various divisions like adhesives and sealants, rubber seals, composite seals, dynamic seals, EMI and RFI shielding products, Extruded products, gaskets, rubber sealing rings, medical components and equipment, molded shapes, O-rings, Sanitary, vacuum face seals and Hygienic seals, semiconductor seals, sheet and roll stock, thermal products divisions. Undertaking the task of enhancing the efficiency of machinery can be a piece of cake with the unique products offered by Darcoid. Darcoid maintains industry leadership by offering innovative, high quality supporting accessories for your high-end machinery.

Basically an O-ring is used to block a pathway that fluid or air may escape through. O-rings are usually put into a groove to hold them in place and then squeezed between two surfaces. When an O-ring is squeezed between two surfaces it shall be taking up the clearance and blocking the pathway that the fluid or air wants to escape through. After an O-ring is applied by squeezing, the rubber once again takes up its original shape. This is how the O-rings seal under low to no pressure. When pressure is applied to the system this also helps the O-ring seal by pushing the O-ring against the groove wall opposite the direction of the pressure and forcing it expand perpendicular to the direction it is being squeezed by the pressure.

Darcoid Nor-Cal Seal is an authorized distributor for Parker seals, O-rings and the likes. These seals have a wide selection of compounds that can meet your application requirements. A wide range of Parker compounds are offered by Darcoid which include Butyl, Chloroprene, PolyAcrylate, Ethylene Acrylate, Ethylene Propylene, Fluorocarbon, Fluorosilicone, High Performance Fluoroelastomers, Hydrogenated Nitrile, Nitrile, Perfluoroelastomer, Polyurethane, Silicone and Tetrafluoroethylene-Propylene.

 

Since O-rings can not be made exactly to their dimensions every time, manufactures are allowed to make them within range of their original dimensions. Variations in the rubber compound and in the manufacturing process cause slight variations in the shrink of the material and effect the finished size of the O-rings. O-rings are commonly made of rubber but they can also be made with plastic or metal. Several different type of rubber compounds exist on the market today because of the different temperatures, chemical exposures and environments that O-rings are subjected too. O-rings come in many sizes, hardness, elastomer and colors to suit various applications.

These O-rings are being widely in use in industrial sectors ranging from automotive to fluid power to semiconductor processing. Parker seals, O-ring products from rubber manufacturers and vacuum face seals of different grades and standards to support the needs of sustainability of your expensive machinery. Darcoid Nor Cal Seal has been serving various sealing and machinery aid needs since 1947. Darcoid Nor Cal Seal is a fabricator of Parker seals, O-rings and more of the likes. The endeavor has been serving as a global leader delivering excellent sealing and machinery aiding solutions.

Prime objectives of Emi shielding seals

The effect of the growth experienced in the electronic industry and the adverse use of electronic equipment in computations, communications, biomedical automation, space and many other reasons has resulted in electromagnetic interference. Commonly referred to by its initials EMI, this problem is bound to be severe in the near future, unless a method of control is arrived at.

The suppression of EMI should be a prime objective for anyone who is involved in this trade, and hence EMI shielding. This can be termed as the reduction of the electromagnetic field, in any given space by using barriers to block the field. These barriers are made of magnetic materials. There are various ways to apply shielding. Shielding is in this case applied to enclosures, isolating all electrical devices, and to cables to keep the wires safely from the surrounding where they run.

In a world that is becoming more and more dependent on electricity, and all its devices, there is need for protection of all the electrical equipment used in all places, both at home and work. EMI shielding sealing solutions are being used in countless devices in the office, home, factories as well as laboratories.

Despite the ever presence of EMI, many, engineers physicists, and other people involved in technology are puzzled by the basic elements involved and all the sealing materials that serve to protect electronic equipment.

Electromagnetic radiation is made up of electric and a magnetic field consists of two fields, electric and magnetic. The electric field is responsible for the production of forces, which are on the charge carriers in a conductor. When an electric charge is applied to the surface of a conductor, in brings in a current, which causes charge displacement within the conductor, cancelling the field applied inside, which causes the current to stop.

The common materials that facilitate EMI shielding seals include metal screen, sheet metal, and metal foam. Different positioning techniques are applied when one is shielding. During shielding, using these materials, one should be careful to make sure that any holes found on the mesh or shield are smaller, compares to the wavelength of radiation. This radiation is what is intended to be kept out, and if this is not adhered to, the enclosure or surface shielded will fail to approximate the conducting surface that is unbroken.

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 shielding and gaskets.These products work by containing or excluding electromagnetic energy in RF modules and components, waveguides and structural enclosures.

Darcoid Nor-Cal Seal is a world renowned manufacturer of sealing solutions and a wide range of accessories like EMI shielding seals and gaskets, die cut gaskets and spliced o-rings, and a distributor for the top manufacturers of seals, gaskets and rubber products. 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.