An Insight into Custom and Standard O-Rings

The O-ring is an elastomer ring commonly used for sealing purposes. The O rings are widely used in commercial and general applications where sealing of liquids or gas is required. The o rings can block a path which may otherwise allow a liquid or a gas to escape and result in leaking. The o ring is placed into a groove to secure them in place and then compressed between two surfaces. By squeezing the o ring, there is no more clearance for it to move and it blocks the pathway of the liquid or gas you are trying to seal in place.

When the system comes under pressure, the o ring is squeezed against the opposite wall of the groove, maintaining a perfect seal even under very high or low pressures. The materials that o rings are made from (elastomers) are naturally springy and have a desire to return to their original shape, so when the pressure ceases, they spring back to their original position, maintaining a seal and readiness for the next cycle.

In a nutshell and to answer the question of what are o rings used for, they are used to seal in a liquid or gas and are the most effective way of ensuring a robust, reliable seal.

O-rings are available in several different configurations and materials to fit different applications. But, first, let’s see what O-rings are.

What Are O-rings?

The majority of mechanical systems need seals. These components are essential to equipment operation because they prevent leakage when joining mechanisms together. O-rings help industries to seal their equipment.

The term “O-ring,” also known as a packing or a toric junction, refers to a torus-shaped mechanical gasket. It is an elastomer loop with a circular cross-section that seats in a groove and is compressible during assembly between multiple parts, establishing a seal at the interface. O-rings are the most often useful in seals in machinery because they are easy to fabricate, inexpensive, and reliable. Buying high-quality o rings from a rubber o rings manufacturer is essential for the smooth operation of your parts. At SantopSeal, we supply high-quality standard and custom O-rings made from FKM Viton, FFKM Kalrez, NBR Nitrile, EPDM, Silicone, PU, Santoprene and many other elastomers.

Various Rubber O-Ring Materials

A rubber O-ring is a doughnut or torus-shaped mechanical gasket used for static and dynamic applications with relative motion and friction. There are many types of rubber materials available for o rings depending on the application requirement. You should choose the right rubber material to have an efficient and long-lasting seal. Depending on the application temperature, chemical contact, and exposure to steam, the material is chosen.

The following are the different types of rubber O-ring materials:

Buna-N/nitrile rubber O-rings:

To develop general-purpose seals that can endure tearing and abrasive treatment, Buna-N or Nitrile O-rings are often used in conjunction with each other. Petroleum oils, water, and some hydraulic fluids can all be used with Nitrile O-rings, having a temperature range of -54 to 149 degrees Celsius. As long as the resistance and temperature requirements are low, nitrile is a good choice.

Neoprene O-rings:

Neoprene, a general-purpose elastomer, is resistant to weather (UV, ozone, oxygen) and petroleum oils. Neoprene O-rings excel in sealing applications where other materials fail. Low compression set, strong abrasion and flex cracking resistance. Neoprene shares nitrile’s temperature range and is used to seal refrigerants in AC and refrigeration systems.

Viton O-rings:

Viton O-rings can handle any movement-related sealing project. This product is useful in silicone gases and fluids, acids, petroleum oils, and halogenated hydrocarbons. Chemical processing, automobile, and residential appliances employ Viton O-rings.

O-rings of Silicone:

Silicone O-rings are utilized in high-temperature fuel injection ports because they work well with water, steam, and petroleum. They function between -84 and 232 C. Silicone O-rings can survive -115°C for brief periods.

PTFE:

PTFE-encapsulated O-rings withstand corrosion, abrasion, non-permeability, chemical inertness, and absorption. They can function between -73 and 260°C. Pure PTFE O-rings are inflexible and difficult to apply, thus they’re best for static applications. Steering devices and paint guns employ PTFE O-rings.

Polyurethane:

Polyurethane is robust and resistant to abrasion and extrusion. This material isn’t suited for compression and heat-resistant O-rings. The latter has a shorter temperature range, -54 to 100 C. Hydraulic fittings, cylinders, valves, pneumatic tools, and weapons require polyurethane O-rings.

Santoprene:

Santoprene has similar qualities to Silicone, Nitrile, and others. It resists alkalis, acids, alcohols, oils, and lubricants. Santoprene has exceptional physical characteristics at many temperatures along with great chemical resistance. Santoprene is also better material than EPDM.

FFKM:

FFKM/FFPM can resist over 1,800 chemicals, including nitric acid, sodium hydroxide, ethylene diamine, and steam while maintaining PTFE’s excellent thermal stability. FFKM o rings are widely used in high temperature and extreme condition applications.

Different Types of O-Rings:

Now that we have gone through the different rubber O-ring materials, let’s check the different rubber O-ring types:

Square-shaped rubber O-ring:

O-rings with a square cross-section are known as washer and lathe cut rings because they have a square cross-section. A leak-resistant connection can be made with this material, which is extremely pliable. The square O rings collapse when they are seated in a groove. To keep the seal between two surfaces, a square rubber O ring is moulded into shape as the surfaces come into contact.

Hollow O-Ring:

In the same way that traditional O rings flow in a groove when force is applied, hollow rubber rings flow in the same way. Hollow rubber O rings shrink and fill grooves more easily than conventional rubber O rings. They can be utilized in conventional and non-standard grooves; however dynamic and high-pressure applications are not suitable for them.

Coated O-rings:

Coating rubber O rings increases chemical, weather, and abrasion resistance by reducing friction. Rubber O rings won’t stick or break when coatings are applied. Rubber O-rings can be coated in many colours to increase durability and productivity.

Back-up O-Rings:

Back-up rubber O rings protect O ring seals from high pressure and temperature. They obstruct or limit the extrusion gap to inhibit O-ring extrusion. Back-up O rings improve rubber O rings’ ability to withstand pressure and heat.

O-Rings Encapsulated:

Rubber-encased O rings contain a flexible rubber core covered by corrosion- and heat-resistant substances. FEP and perfluoro alkoxy-copolymer are jacket kinds (PFA). FEP can withstand a wide variety of temperatures and harmful substances. PFA is like FEP but has greater mechanical qualities and stress/cracking resistance. Moving parts can harm the jackets of encapsulated rubber O rings, limiting their use.

Material Selection for Rubber O-rings:

The following are the factors that you must keep in mind while selecting the material for rubber o ring:

Properties:

Depending on its properties, the material you choose could have a long or short lifespan, necessitate different production methods, or be more or less expensive than similar alternatives.

Temperature:

Make a note of the temperature range in which your O-ring needs to perform properly. For high-temperature applications, nitrile-based O-rings are preferred, while different silicones can withstand a wider temperature range.

Adaptability:

In order for your O-ring to fit snugly into its matching component, it must have a smaller diameter than the installation groove. This feature contributes to a secure seal.

Strength:

Examine the material’s hardness. Increased application force on an O-ring requires an O-ring with a greater Shore Hardness (SHAR).

Dimensions:

The diameter and width of the mating surface’s groove, as well as the material’s flexibility, should be taken into consideration when determining the proper size.

Finishing:

O-rings should have a surface polish with a narrow range of 5–16-inch RMS surface roughness to minimize friction or hastened wear.

Benefits of O-rings

The O-rings are useful for decades in various applications, including industrial and automotive engines, manufacturers of utensils, balloon pumps and compressors, and many other such technologies. The following are a few benefits of O-rings-

Multiple sizes

O-rings come in multiple sizes, from small ones that fit on a pen to ones that seal a pipeline. People alter the O rings and shrink to fit the new requirements as modern technologies get smaller and easier to manipulate.

Tight seal

The primary function of O-rings is to provide a tight seal to various equipment pieces that prevent liquid leakage. This is the reason for continuing the use of O-rings.

Cost-effective

Several types of equipment prevent products from leakage. But O-rings have become more popular than others due to the cost. FDA-approved O-rings are the cheapest and easiest to obtain of all the materials required and required for the conduct of a complex procedure.

O-rings are an essential component which provides great sealing solutions. They are widely used throughout many industries.

SantopSeal is a Standard and custom O-rings manufacturer providing premium quality torus-shaped Rubber O-ring seals. We supply Standard, FDA-compliant food-safe, and USP class VI certified O-rings to the United States and other international markets.

Our Standard and FDA-approved custom O-rings help prevent leakage of liquid or gas by blocking the mating paths in your products. They are compressed between two surfaces to secure the escape area. As a standard and custom o ring manufacturer, we use various Elastomer including Santoprene TPV material and many other materials listed below to make an O-ring that works in the temperature varying between -76° F to +250° F / -60° C to +135° C and beyond.

At SantopSeal, we provide standard and custom O-rings made from,

Santoprene TPV
Nitrile or Buna-N (NBR)
Viton® FKM (Fluorocarbon)
EPDM
Kalrez® (FFKM)
Neoprene
Silicone

Additionally, SantopSeal provides o rings that are

FDA-approved or Food Grade
General grade
Medical grade or USP Class VI Certified
Available in Black, White, and Natural color or custom color
UV Resistant
Flame Retardant
UL Compliant
Square Cross Sections O ring or Custom Cross Section O ring
Spiced or Vulcanized O ring
Durometer hardness ranging from 40 Shore A to 90 Shore A

Our capability also includes O ring cord manufacturing according to customer requirements, including Solid O ring cord, EPDM sponge O ring cord ranging from low to medium density, and custom cross-section and square cross-section o ring cord. All the O ring cords are available in roll and also as custom cut to length.