IQS Newsroom Articles on O-rings
About O-Rings and O-Ring Manufacturers Including: Clear O-Rings, Flat O-Rings, Large O-Rings,
Metric O-Rings,
O-Ring Kits, O-Ring Seals,
Rubber O-Rings, Silicone O-Rings, Teflon O-Rings & Viton
O-Rings.
O-rings are round, ring-shaped molded rubber sealing devices which are critical for creating
seals between connecting pieces in machines belonging to nearly every industry. Named for their O shape, o-rings are both extremely simple and extremely critical in their function. O-rings function similarly to the way gaskets do in connecting valves, tubes, vacuums and hydraulic flow applications with an impermeable seal between two joints. All standard O-rings have round profiles, but some gaskets that perform exactly the same as O-rings have
flat or square profiles. O-rings are manufactured by a relatively cost-effective process, making them a simple, fairly cost-effective solution for machinery and equipment manufacturers. O-rings are made in a wide range of synthetic and natural elastomers, each of which carry different application-specific properties. The most common types of
rubber o-rings include
viton o-rings,
teflon o-rings, neoprene o-rings,
silicone o-rings, which are naturally
clear, and nitrile o-rings. O-rings are made to English measurements or as
metric o-rings, and o-ring suppliers often supply bulk o-rings of assorted sizes, including
large o-rings in
o-ring kits to manufacturers who use o-rings commonly in manufacturing.
Hydraulic, pneumatic and vacuum flow applications, whether they involve static parts or moving joints, use o-rings of all sizes and materials to create seals where tubes or other equipment join together. Aerospace and aviation industries in particular rely on o-rings in critical applications, such as engine turbines and brake systems. O-rings used in aerospace applications require extremely high resistance to extreme temperatures and include materials such as silicone, EPDM, perfluoroelastomer and fluorosilicone. Petro-chemical hydraulic applications in oil refineries, chemical processing and water treatment facilities use o-ring seals with high chemical and fuel resistance made from materials such as teflon, nitrile, viton and perfluoroelastomer. Silicone o-rings are especially resistant to UV weathering, dry heat and wide temperature swings, while neoprene is often used to seal refrigerants such as freon in liquid chiller systems and heat exchangers. Due to o-rings' low manufacturing cost, some rubber o-rings and silicone o-rings are used in jewelry accessories as necklace strings and around ear plugs.
Viewed at a cross-section, o-rings are disc-shaped; when placed within a groove between two joints and pressure is applied to the o-ring, the disc-shaped cross-section deforms. This compression deformation is what causes o-rings to create a seal, and as more pressure is applied either within or without the seal, the o-ring deforms even more within the groove as it is pressed up against one side, further reinforcing the seal. O-rings' sealing capabilities are based on their resilience, or their ability to retain their original shape long after deformation. Static o-rings, used to seal two rigid, nonmoving parts, will remain stationary and therefore do not require any lubricants. O-rings joining joints with motion typically require o-ring lubricant to reduce wear; lubricants are often made from elastomers such as silicone or neoprene, but manufacturers must be careful never to use o-ring lubricant with an o-ring made from the same materials, at the risk of eroding the o-ring.
O-rings have been the center of many important technological advances in the last several decades, specifically since the disaster of the space shuttle Challenger takeoff in 1986, which was traced back to a faulty o-ring. Due to below freezing temperatures the morning of the launch, the o-rings in the Challenger's solid rocket boosters had deformed permanently, failing to decompress and create an effective seal. Extreme temperature endurance had not been taken into account during the o-rings' engineering, and as a result the Challenger exploded during liftoff, killing all seven of its crewmembers. Since the Challenger disaster, the o-ring and gasketing industries have made extensive investigations into material properties and endurance under harsh conditions. Regulations have been made regarding o-ring packaging and labeling, expiration dating and quality control. O-rings used in critical applications, such as aerospace or aviation, are examined under UV lights before distribution for any stresses or fractures which might cause sealing failure.
O-Ring Types
- are extremely resistant to polar solvents such as alcohols,
acetone and MEK. However, EPDM o-rings are not a good choice for applications
that involve petroleum oils and greases.
-
are commonly used in conjunction with power steering liquids, transmission
fluids and engine oils. Compared to polyacrylate o-rings, these have
a better low temperature performance but do tend to swell up more.
-
have excellent heat stability as well as great oil and fuel resistance,
but they should not be used in dynamic applications due to their poor
mechanical properties.
- have similar properties to standard nitrile
rubber, but are ozone resistant. Some popular uses include automotive
refrigerants and high temperature hydraulics.
-
are made of an advanced material that is being implemented more and
more on a daily basis. Kalrez resists over 1,800 different chemicals
and is stable in temperatures up to 620 °F; it is also used in aggressive
chemical processing, oil and gas recovery and in aerospace and petroleum
applications.
- are o-rings whose measurements are specified in metric units.
- are made of a material that was the first synthetic rubber.
During WWII, it served as the primary seal material, but today it is
mostly used in refrigerant applications.
-
are by far the most popular type of seal material used in the world.
Nitrile o-rings are carbon triple-bonded to nitrogen, which provides
good resistance to oils and fuels.
- are sets
of o-rings that are designed to replace faulty o-rings.
-
are extremely resistant to petroleum oils, ozone and oxygen. However,
polyacrylate o-rings have relatively poor water resistance and low temperature
flexibility.
- are made of rubber and synthetic rubber materials.
-
are made of a material that is commonly used in hot air applications
as well as devices in the medical field. The silicon-oxygen structure
gives silicone o-rings good thermal stability.
- are gaskets used in static joints.
-
are made of a material that is one of the most commonly used for seals.
Its popularity can be attributed to its good chemical resistance and
extreme upper temperature limit.
O-Ring Terms
-
When materials stick or cling to one another.
- When a material undergoes
physical changes over time.
- A hard ring
that is placed in the gland between the o-ring and the groove walls in
order to prevent extrusion.
- The resulting product
from one mixing operation.
- A small cavity that is
surrounded either completely or partially by walls.
- Any of the various
materials that are elastic and resemble rubber. Elastomers can be used
instead of springs as energizers.
- A device used in
some o-rings that acts to retain the ring's natural shape. Often,
either a spring or an elastomer serve as the energizer at the core of
the o-ring.
- The resistance to
motion when two or more surfaces rub against one another.
- Cavity into which an
o-ring is installed, which also has the groove and mating surface of the
second part.
- The size measured
from any inner point of an o-ring to the inner location on the direct
opposite side, creating a straight line.
- The slippery, lubricated
qualities an o-ring material has.
- A material's
tendency to resume its original shape after deformation.
- O-rings that meet
and/or surpass standards of the United States military.
- When a mold is misaligned and causes an out-of-round
cross section of an o-ring.
- The size
measured from an outside point of an o-ring to that same point on the
direct opposite side, creating a straight line.
- A groove around
the mold cavity of an o-ring that is used to accept excess material from
the cavity in order to create a better fit.
- A line outside
of o-rings that is left-over from when the two mold plates met.
- Any of various
resins that vary in flexibility and are used in chemical resistant coatings,
foams and adhesives.
- Cross-section compression
of an o-ring gland assembly that shows between the surface of the groove
bottom and surface of the mating metal part.
- Improved strength,
lubricity and resiliency by combining sulfur and/or other additives with
both heat and pressure.
- The bulging or
increased size of an o-ring due to water intake.