Known as ‘cold set’, this will create an unviable seal, leading to … They offer good resistance to high temperatures (up to 210 C), but are prone to failure below -15 C in dynamic applications when they tend to become too stiff and inflexible. SSP Manufacturing Inc. © 2021. There are various types and arrangement of the mechanical seals being used for the centrifugal pumps. Double “O” ring seals have been used for many years to provide an aseptic seal for glass electrodes in stainless steel housings in fermenters. What is a rubber compound? These are intended for use in basic design consideration and to understand the core principles involved in o-ring gland/groove design. Oil exploration and extraction presents very challenging conditions for Elastomeric seals; a combination of extreme temperatures, aggressive chemicals and gases, abrasive media, high pressure and destructive forces, subject seals to the harshest environments in the world. Why is FDA-approved Silicone Rubber Chosen for Gaskets and Seals in the Food Processing Industry? High-temperature sealing o-rings are, as the name implies, designed to withstand extreme heat while continuing to provide a reliable seal between two surfaces or components. O-rings are used primarily for sealing. A u-cup is an o-ring formed into a u-shaped channel. O-rings are very versatile and available in various sizes. Common types of external seals The types of seals most commonly used with rolling (ball and roller) bearings are contact or lip seals; non-contact seals; and, to a lesser degree, various types of bearing isolators that combine the functions of contact and non-contact seals in different ways. This post discusses static and dynamic types in detail. This includes O-rings, D-rings, back-up rings, cover seals and gaskets. Nitrile rubber o-rings are a tough and fairly robust type of seal that holds up well in physically demanding roles. Different types of dynamic movements - for example, rotary, reciprocating and oscillating - demand that o-rings be manufactured with different material qualities to perform to the optimal level. Some of the common types of O-ring materials include PTFE, Nitrile (Buna), Neoprene, EPDM Rubber and Fluorocarbon (Viton). There are any number of high-performance materials used in the production of o-rings, ranging from nitrile and silicone rubber to fluorocarbons, metals and more. The base monomer or monomers is used to classify the type of rubber, for example: Nitrile, Silicone or Neoprene. You can change your cookie settings by reading our, For general enquiries: 03457 201201 (standard rate line), Raspberry Pi, Arduino & Development Tools, Engineering Materials & Industrial Hardware, Pneumatics, Hydraulics & Power Transmission, Optocouplers, Photodetectors & Photointerrupters, PCB Cutting, Punching, Forming & Drilling, Development Tools & Single Board Computers, Clocks, Timing & Frequency Control Circuits, Industrial Push Buttons, Pilot Lights & Control Stations, Water Meters, Thermometers & Pressure Gauges, Pneumatic Air Compressors, Boosters & Vacuum Pumps, Pneumatic Counters, Logic Controllers & Timers, Power Transmission - Linear Bearings, Housings & Blocks, Power Transmission - Gaskets, Seals & Packings, Power Transmission - Linear Shafts, Rails, Ball Screws & Lead Screws, Power Transmission - Linear Slides, Guides & Positioning Tables, Power Transmission - Rod Ends & Spherical Bearings, Power Transmission - Roller Chains & Accessories, Electronics Cleaners & Protective Coatings, Writing & Drawing Instruments & Accessories, Electronics Components, Power & Connectors, Everything You Need To Know About O-Rings And Seals. Where O-rings are used. As we’ve seen in some of the above sections, there are many different o-ring materials in widespread use, and picking the right sort for the precise task in question is very important if you want it to perform reliably over time. Each of these have described below in detail. [Figure 1] Hydraulic seals used between nonmoving fittings … Use one of the links below to view our top ranges of O-rings on the RS website, Freudenberg Sealing Technologies Simrit O-rings. This seal prevents particle, vapour and fluid leakage to protect and maintain pressure whilst keeps debris out, ensuring proper function and safety. Phosphate ester hydraulic fluids, brake fluids and halogenated hydrocarbons are damaging to nitrile, and it’s not the best choice for high temperature or pressure demands, The nitrile o-ring temperature range is usually anywhere from -50 C to 120 C. Rubber o-rings are perhaps the most common type, serving an enormous array of purposes and functions in less specific or demanding applications than some of the higher-tech variants seen in heavy industrial environments. For more detail on all types of O-ring materials and designated temperature ranges, feel free to contact our expert support team any time - they’ll be glad to offer further advice and assistance on specific high-temperature seals, materials and applications. They’re commonly used due to the inherent resilience of stainless steel o-rings, which means seals can spring back promptly once pressure is reduced. For short stroke applications, smaller diameter O-Rings perform well. An O-ring is a donut, or torus shaped seal typically used to prevent the passing of air or fluid. Nitrile o-rings are a popular type of rubber seal gasket that’s used in a wide range of applications and environments - they’re broadly seen as a general-purpose o-ring type, with reasonably resistant sealing properties against water, gasoline, petroleum … Oil seals are used to protect shafts and bearings from ingress of … When applied correctly the O-Ring will function well in most dynamic applications. Nitrile O-ring seals. The o-ring, generally made of some form of elastomer, sits in the join between these two parts, and becomes compressed in order to help form a tight seal. ... (parts). In situations involving little or no motion relative to the seal, the O-ring application is STATIC. Glide ring seal with an O-ring energizer for light- to medium duty applications, made of PTFE 40% bronze with an NBR O-ring. It usually consists of a nitrile rubber O-ring and a support ring (retaining ring). John Crane Type SB2A O-ring Pusher Seals deliver maximum reliability and uptime. Appropriate hardware configuration, durometer, and feet-per-minute values are important for a proper sealing. What is FDA CFR 21 177.2600 and Why is it Important for Your Food Processing Business ? Seals prevent fluids from escaping through the gaps in mating pieces of hardware. O-Ring Colors. Viton® o-rings are a popular alternative to the widely-used nitrile seals. Standard silicone o-ring temperature range is generally quite wide, from very low to reasonably high. As noted above, you’d use an o-ring very similarly to the way you’d use any other type of gasket: the elastomer-based circular cross-section sits in a specially engineered groove (the geometry of which is fairly universal), where it becomes compressed between two or more parts once they’re assembled and interlocked. Dynamic Seals O-Ring. The resulting o-ring seal is both economical and reliable, as well as relatively resilient and easy to maintain/replace when needed. This cross section provides an initial compression. It also forms a better seal than plastic. This is less of a concern for o-rings used in static applications, as the only stress force they’ll be under is usually compression (to which they tend to be fairly resilient). A wide range of elastomers is available. Potential drawbacks of NBR, Buna-N and other nitrile o-rings include limited ability to withstand particularly high temperatures, and weaker ozone, UV and weather resistance than many other o-ring types. Each rubber type has is strengths and weaknesses which dictate where a seal can or can't be used. They are usually non-metallic, quite soft rings placed in a housing, or arranged in a mixture of rings creating a sealing unit. **Disclaimer: It is never safe to assume an o-ring … More information, including design criteria on O-ring … However, mechanical failure under high pressure can easily cause extrusion or destruction of the o-ring, which is why it’s important to choose the right material for the precise environment you’re looking to use it in. One of the key strengths of an O-ring-type seal is that after the parts it joins are disconnected and the compression forces acting on it are removed, it will return to its original shape. O-rings are normally used as seals in several ways, and dimensions of the groove or gland will also vary with the cross section of the ring, the type of operation, and the amount of pressure used in the system. The O-Ring sits in the middle of a gland when it’s at rest, but as pressure begins to rise in the sealing system, the O-Ring shifts to the opposite side of the pressure. The point of the seal is to keep the air in, and push it out the other side, which increases performance. Description. Liquid or air pressure "inflates" the u-cup and affects a seal. entirely with elastomeric O-rings. Metallic o-rings and metal o-ring seals are often found where an extra hard-wearing gasket is required in high temperature or high-pressure components, in heavy machinery and industrial sectors. O-Rings. It is ideal for use with environmentally hazardous and abrasive fluids, most often used in pumps in pulp mills, minerals processing and other slurry duties. O-ring manufacture usually relies on techniques like compression, transfer or injection moulding, machining, or extrusion. Again, all industrial o-ring purchases should be carefully planned with direct reference to the specific role and environment the seal is required to perform in. These variables may include pressure of the system, surface finish of metal parts, O-ring stretch, and squeeze, etc. They possess a circular cross-section which works as a seal both in static and dynamic applications, being compressed amid mating surfaces within walls of the gland into which they are installed. Designed to suit common UK housing dimensions, available with a variety of rotary types, but most commonly supplied with rotary types 10 / 20 / A1 / A2. Our sealing experts can guide your to pick the best material for your needs., Phelps is a major manufacturer, fabricator and distributor of Industrial Gaskets, Compression Packing and Sealing Devices Established in 1945 to deliver the best performing fluid sealing products at competitive prices globally. Although they are both used for sealing, gaskets and ‘O’ rings are actually quite distinct in appearance and application. These dimensions will also be different if the O-ring is sealing a liquid which has a low volume Hydraulic seals used internally on a sliding or moving assembly are normally called packings. Hydraulic seals used internally on a sliding or moving assembly are normally called packings. An O-ring, also known as a packing or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface. There are a number of popular high-temperature o-ring material choices, including nitrile, hydrogenated nitrile, silicone rubber, polyacrylate and more. An engine o-ring, especially one used in high performance or turbo engines, is a good example of a product that has to be rugged enough in design and material construction to handle various challenging requirements of temperature, pressure and chemical compatibility. This means there’s a fairly uniform mechanical stress placed on all contacting surfaces of an o-ring. The o-ring manufacturing process is relatively straightforward, and the specifics of any given o-ring design and production run generally take into account required quality, quantity, application environment, cost-effectiveness, chemical and pressure compatibility, longevity and lubrication requirements. What You Should Know About 4 FDA-Grade O-ring Materials? Dynamic. Central ‘O’-Ring Mounted, short fitting length Stationary Seal with anti-rotation pin slot feature on rear face. When you move away from engineered seals like O-rings, the next technology to use in the sealing family is a gasket. O-ring seals and grooves. An oil seal used for sealing a rotating member is called a rotary seal. Universal. Their name, as implied, simply refers to a classic doughnut or torus shape, and they exist purely to create a better, more leak-proof seal between two other components, with the aim usually being to prevent the unwanted escape of gases or liquids. It basically comprises of a cross-section, which is designed into a groove. Northern elephant seal. Silicone o-rings are very much a gasket/sealant industry standard today. This articles describes some of the commonly used mechanical seal types like Cartridge type mechanical seals, Balanced type, Unbalanced type, Conventional, Pusher, and Non-Pusher type of mechanical seals. When vacuum technology components are detachably joined, seals must be used to prevent ambient air from flowing into the vacuum. A seal may consist of more than one component, such as an O-ring and a backup ring, or possibly an O-ring and two backup rings. Seals and O-rings are used to join two parts of a machine, engine or other mechanical assembly by filling the space between both parts, creating a filled and seal space in between. O-ring kits from Viton® suppliers are actually made from fluorocarbon rubber, making them excellent for withstanding higher temperatures and offering stronger chemical resistance (petroleum oils, acids, silicone fluids and gases) than most basic nitrile o-rings can cope with. Namely: nitrile, EPDM and Neoprene. The force needed to compress the seal is produced by the cross-section diameter, and the durometer. Used as static, dynamic, radial or face seals. This is known as the secondary seal and may be an o -ring as shown, a v -ring, a wedge or any similar sealing ring. On the whole, static o-rings are created from less robust and hard-wearing materials than their dynamic equivalents. Nitrile O-rings, which have a temperature range between -54 and 149 degrees Celsius, are suitable for use with water, petroleum oils and some hydraulic fluids. A seal may consist of more than one component, such as an O-ring and a backup ring, or possibly an O-ring and two backup rings. O-rings are very commonly found in pumps, cylinders, connectors and valves, helping to seal joins between separate parts and prevent leaking of fluids and gases. Comparison of Common Seal Types. It is a static seal to prevent hydraulic oil from leaking from the gap between the end cover and the cylinder wall. This section contains descriptions of the elastomers used in seal applications. Resistance to petroleum oils, acids, silicone fluids is good, and Viton® is highly resistant to oxidation, UV damage, fungus, ozone, oils, and petroleum-based lubricants. NBR 70 o-rings are also suitable for food-grade use once compounded appropriately. An O-ring is described as a static or a dynamic seal, depending on the direction of the squeeze applied to its cross section. In this guide, we’ll look at some of the more common types of o-ring seals on the market, and discuss where and when to use them. Aircraft o-rings and aerospace o-rings generally need to be highly chemically resistant, and able to operate within a wide range of temperatures and pressures in order to keep an aerospace craft’s powertrain running cleanly, efficiently and smoothly. As, many of these variables are related to each other, thus they are considered important in dynamic sealing conditions. NBR o-ring kits and NBR seals are found in a staggering number of applications. The various types of O-ring seals are described in this section under “Scope of O-Ring Use.” O-rings are also used as light-duty, mechani-cal drive belts. If dynamic stress is involved, precision O-rings that are manufactured especially for this purpose or alternatively mechanical seals or … The O-ring may be used in static applications or in dynamic applications where there is relative motion between the parts and the O-ring. Know About Dynamic Seals and Their Applications. Seal Types & Gland Design 4 11 Major Classifications All O-ring seal applications are categorized in terms of relative motion. It’s also important that the components being joined together in a dynamic environment are carefully designed and finished, such that they will not abrade, shear and eventually destroy the O-ring positioned between them. While all o-rings require some degree of lubrication in order to perform to optimal levels, dynamic o-rings require heavier and more frequent lubrication (as well as more regular checking, maintenance and replacement) than static versions. This makes them ideal for demanding industries and environments such as oil and gas refineries, chemical processing, or any other scenario where a high-temperature seal is required, such as performance transport applications like turbo engines and aerospace engineering. The seals used in rotating, reciprocating, or oscillating motion are known as dynamic seals. O-rings are used primarily for sealing. Choosing the best product for the job depends on finding the correct size and shape for the specific role you have in mind. For use in an engine, an oil o-ring has to be created specifically from compatible hybrid materials that allow it to maintain crucial o-ring properties (flexibility, incompressibility) while offering more robust resistance to heat, pressure, o-ring leaking and chemical attack than a standard elastomer typically could. Our website uses cookies and similar technologies to provide you with a better service while searching or placing an order, for analytical purposes and to personalise our advertising to you. Finding the correct nitrile o-ring for the job will depend on getting the right grade to stand up to the task at hand. The following are different types of dynamic seals: The O-rings act as rotary seals under appropriate conditions. The end cover seal is used to seal the cylinder end cap and the cylinder wall. Paintballing: Paintball guns use compressed air to shoot globs of paint at unsuspecting enemies. Reciprocating Dynamic Seals; O-Rings are used within dynamic reciprocating applications, usually hydraulic or pneumatic piston or rod seals. It is widely used … More information, including design criteria on O-ring drive belts and their application will be found in Parbak™ Back-Up Rings. The O-ring is one of the simplest, most common types of seal for a wide range of static and dynamic applications. … Most O-rings are made from synthetic rubbers. Common elastomers for use in aerospace-type applications include nitriles, ethylene-propylene, fluorosilicones and more. 15. O-rings are mechanical gaskets with a round cross section. For more advice and information on suitable products to use as engine o-rings, feel free to contact our customer service team through the support pages on our site. Guide to Different Types of O-ring Applications, types of seals used in various dynamic, as well as static applications, Tips for Selecting the O-Ring Squeeze Ratio. Nitrile o-rings are a popular type of rubber seal gasket that’s used in a wide range of applications and environments - they’re broadly seen as a general-purpose o-ring type, with reasonably resistant sealing properties against water, gasoline, petroleum … Phelps carries a wide range of O'rings for various fluid sealing applications. Basically an O-ring is used to block a pathway that fluid or air may escape through. Meet the Players For the purposes of this article, we will focus on just three common rubber types found in O-rings and similar automotive seals: Buna N, Viton, and EPDM. Global O-Ring and Seal has developed o-ring groove design and gland dimension guidelines. The sealing compression is affected by the stretch. These typically require a flat flange and a bolted joint. The round cross-section is economical to produce and provides a bi-directional seal that is easy to install. Spring-energized seals provide durable and reliable sealing solutions in critical applications and under extreme operating conditions in different industries. The end cover seal is used to seal the cylinder end cap and the cylinder wall. O-Rings and Back-up Rings Your Partner for Sealing Technology 2. METAL SPRING ENERGISED C RING SEAL. To achieve food grade approval, an o-ring manufacturer must also take into account extractable ingredients/compounds if the seal is to be used in direct contact with aqueous, acidic or fatty foods and drinks. It is true that petroleum products will degrade natural rubber. An O-ring is an internal part found on all plunger-system blasters. IV. What is the Difference between Static and Dynamic O-rings? The seal between the gland plate and stuffing box, this is usually a gasket, or o -ring. O-ring seals for Flared Fittings come in two primary types that use O-ring face seals (ORFS): An ORFS fitting has a replaceable elastomeric O-ring held in a groove in the face of the fitting. Typical applications include fuel cap gaskets, fuel system o-rings, and valve cover seals. In very basic terms, o-ring seals work by sitting in a groove or channel between two surfaces/components that are going to be mated or pushed together. The O-ring is considered a universal sealing device. Know How to Identify O-ring Failure in Fluid-Power Systems. Know about Different Types of Static Seals. Nitrile o-rings are a popular type of rubber seal gasket that’s used in a wide range of applications and environments - they’re broadly seen as a general-purpose o-ring type, with reasonably resistant sealing properties against water, gasoline, petroleum oils, crude oil, propane and some hydraulic fluids. Securing the best choice in any given scenario will generally be a balancing act between the specific operating temperature needed, and the most economical material option at that performance point. An O-ring forms a seal in the plunger tube, and in direct plungers, it also forms a seal in the plunger head. NBR 70 o-rings are ideal for uses where oil resistance and low-temperature functionality are required - as such, they’re often found in military applications and automotive or aircraft fuel systems. We supply Hydraulic & Pneumatic seals for single and double acting cylinders, composite piston seals, compact seals, independent wear rings, bonded seals, static seals (O Rings), and symmetrical seals. The design of the O-ring groove is relatively straightforward -- by following well-developed rules for groove geometry, an economical and reliable seal is obtained. The force needed to compress the seal is produced by the cross-section diameter, and the durometer. Oil and Gas Drilling O-rings (ED Resistant O-rings, Norsok M-710 Seals, NACE TM0297 Seals) Automotive O-rings and Oil Seals : Good Wear Resistance Moderate Compression Set Resistance Moderate Short-Term Resilience Excellent Permeation Resistance : Neoprene® (Chloroprene) Standard: -35°F to 250°F Specialty: -67°F to 250°F : Refrigerants (Freon) [Figure 1] Hydraulic seals used between nonmoving fittings … Many basic rubbers and polymers aren’t suitable for use with oils, fuels or solvent-based compounds. Because there are so many different sizes and gauges of o-ring distributed throughout most aircraft engines and systems, most sales for aerospace and aeronautics are through bulk orders of multi-size o-ring kits. More information, including design criteria on O-ring drive belts and their application will be found in A shaft hardness value of 55 Rockwell is typically required for a successful rotary O-Ring. O-rings function on the principle that even pressure placed on the (more or less incompressible) o-ring material creates predictable deformation patterns around the perimeter of the gasket in its groove. Even though the o-rings are made from several materials, they are commonly moulded in one piece from elastomeric material. Nitrile - also known as NBR - is probably the most widely used elastomer in the seal industry at the time of writing. Used in the different media conditions due to extend material options . Below are a variety of o-ring colors and the most common materials associated with each color. Static seals are categorized on the basis of squeeze, which is applied on the cross section of the O-ring. It usually consists of a nitrile rubber O-ring and a support ring (retaining ring). Incorporation of FDA-Approved Metal & X-Ray Detectable Rubber Materials, O-rings Used in Static and Dynamic Applications, Everything You Need To Know About FKM Seals, Know the Benefits of Metal and X-ray Detectable Seals and Gaskets, Get Introduced to a Few Popular Hydraulic Seal Materials. Static Seal. Performance of these seals is affected by various variables. Low temperature performance. The seal between the rotating member and shaft or shaft sleeve (4). Up to a point, this will create a tighter and tighter seal, but it’s vital not to put more stress on an o-ring than it’s designed to handle, as too much deformation will eventually cause the seal to start leaking again. Glide ring seal with an O-ring energizer for light- to medium-duty applications, made of hard grade polyurethane and an NBR O-ring. This system is suitable for lower level hazards, provided that release of microorganisms is minimized and there are adequate disinfection procedures for dealing with leakages ( Werner, 1992 ). The point of the seal is to keep the air in, and push it out the other side, which increases performance. An interactive O-Ring Chemical Compatibility lookup tool is a guide only. It basically comprises of a cross-section, which is designed into a groove. Whether sold individually, in large wholesale batches or - as is increasingly common - as part of a highly flexible range of o-ring kits, the basic form and role of o-rings are generally the same across the board. Some of the materials used in the manufacture of o-rings have of course become more high-tech over time, but essentially o-rings remain a beautifully straightforward and reliable solution to a problem that was first brought up more than a century ago. Carbon dioxide often presents an issue for many types of o-rings, as softer materials have a tendency to absorb the gas over time and swell up. The O-Ring is very much an indispensable component. Over time and in certain industries, specific o-ring colors have been used to differentiate between materials. A number of common seal types, T-Seals, U-Cups, V-Packing and other devices, have been, and are still used for both dynamic and static seals. You could argue that the o-ring is a bit of a ‘living fossil’ in terms of manufacturing components. Under pressure, the o-ring will shift in its groove towards the lower-pressure side of the seal, forcing it more and more tightly against the inner and outer walls of the gland created between two components. Silicone rubber compounds typically offer very good resistance to ozone, acids, water, and decent resistance to weathering and heat, making them great for outdoor applications.