Elastomeric seals and o-rings are used for a wide range of
industries, including the pharmaceutical, semiconductor, petrochemical,
chemical processing, heavy equipment manufacturing and more. High
performance seals and o-rings that perform reliably over extended
periods resulting in reduced equipment downtime and longer maintenance
All seals and o-rings can be
custom molded to strict design specifications, and material ranges from perfluoroelastomer FFKM to Viton, nitrile, epdm, silicone and more.
Of the many kinds of sealing technology available in products
manufacturing and machine design, the use of the o-ring is perhaps the
most common and extensive. O-rings are used in appliances found in our
homes as well as in heavy industrial machines like hydraulic cylinders
and jacks. They are also typically found in many types of hand tools
like pneumatic hammers, drills and air tools.
The failure of many devices and tools can very often be narrowed down to
the o-ring. As a sealing component, the o-ring's failure will result in
the lost of hydraulic fluid and pressure and sometimes, a simple
replacement of the o-ring would be sufficient to put the tool back into
operation. However, there are heavier equipment that will require
specialized service from competent technicians if o-rings were ever need
to be replaced.
The selection of the right o-ring sizes is of critical importance and
the sizes of o-rings are determined by its internal diameter as well as
the diameter of its cross section area. The o-ring, when installed into
the mount, should seat nicely and with strict tolerance within the
recess of the mounting. The surface of the mounting that comes into
direct contact with the o-ring should be even so that pressure on the
o-ring is distributed evenly throughout. The o-ring, when compressed,
should exert a pressure against the contact surface of the mounting of a
value that is greater than the pressure of the fluid to be contained.
This is essential for the proper sealing of the fluid and ensures that
no leakage will occur. The selection of the o-ring should therefore be
made with the design and shape or size of the mounting contact surface
into consideration. The wrong size o-ring will result in sealing
Environments where sealing components are subject to abuse include that
of extreme temperatures conditions as well as exposure to corrosive
chemical media. Elastomeric seals have to perform under the most
demanding conditions, and failure would have implications in terms of
equipment downtime, environmental consequences and safety of operation.
Thermal Effects on O-Rings
Low Temperature Effects: Seals and o-rings behave in ways that
can compromise their performance when under conditions of low
temperature. Elastomeric materials, like most other materials, contract
at low temperatures. A sealing component that is subject to low
temperatures will experience a reduction in compression and subsequent
failure due to leakage. Brittleness and lack of flexibility sets in when
low temperature limits are exceeded, and failure of seals happen through
hardening of the seal material and reduction of its ability to resist
deformation. Low compression set, which is a desirable property of
elastomeric material, is also compromised, resulting in the failure of a
seal to return to its original dimensions upon the release of a
sustained loading. Choosing the right material is crucial in effective
High Temperature Effects: The deterioration of o-rings and seals
happens at elevated temperatures. High temperature causes the softening
and swelling of seals and o-rings, resulting in greater friction in
dynamic applications. High temperature also causes physical and chemical
changes within the elastomeric material which become irreversible over
extended service conditions. Volume changes, induced compression set as
well as an increase in seal hardness are the results of material
deterioration. Many elastomeric material are capable of withstanding
elevated temperatures of up to 300 degrees F, with perfluoroelastomers
at the high-end of performance at 600 degrees F for short duration
The following serves as a guideline in the choice of material for
elastomeric seals such as o-rings, gaskets and diaphragms. There can
never be one size fits all when it comes to the choice of an o-ring for
specific applications. Depending on the industry, sealing products may
be subject to varying degrees of abuse. Generally, the elastomeric
material that these products are made of are expected to function even
at elevated temperatures while in contact with corrosive chemical media.
Design criteria will also have to consider factors as ozone degradation
with prolonged weather exposure. The most common material grades that
are used in its manufacture are as below:
1) NBR Rubber
Nitrile rubber has extraordinary mechanical
properties and that is the reason that it is been used in an extensive
range of applications. Nitrile rubber, or NBR, is not suitable for use
in applications where exposure to weathering is expected because it
suffers degradation as a result of ozone attack. Resistance to wearing
as well as abrasion is outstanding, and nitrile rubber is unique in its
ability to return to its original form upon the release of a sustained
loading. This characteristic of NBR material is termed as low
compression set, and is a critical factor to be considered as any
changes in dimensions would have an adverse effect on joint seal
integrity. NBR rubber is also referred to buna N and Nitrile, and is
chemically known as acrylonite-butadiene copolymer. A common use of NBR
elastomeric material is for the manufacturing of o-rings and seals for
use in hydraulic cylinders in hydraulic equipment manufacturing. This is
due to its excellent resistance to the abuse of wear and abrasion.
Buna N, NBR and Nitrile rubber are the generic terms that refer to the
acrylonitrile-butadiene copolmer. A sector of industry where the use of
NBR rubber seals is commonplace include hydraulic equipment
manufacturing, as in hydraulic cylinders. Properties of NBR include
excellent resistance to abrasion and wear, the ability to undergo
loading without permanent deformation (low compression set) and good
tensile characteristics. Its superior mechanical characteristics makes
it ideal for use in many applications, though it lacks resistance to
2) EPDM (ethylene-propylene)
The elastomeric material of choice in the
automotive manufacturing industry is EPDM, or ethylene-propylene.
Typical performance requirements of sealing parts like o-rings and
gaskets in automotive components factor in resistance to substances and
fluids like greases, alkalis, ketones and hydraulic fluids. EPDM
material can resist high temperature and aggressive media, while
continuing to perform to expectations.
A seal design engineer will need to factor in varies concerns like
service conditions, change of service environments, the ability of the
seal to withstand thermal and chemical conditions for sustained
durations in operations, as well as cost efficiency when it comes to
choosing the right elastomeric material for the seal. There is also the
possibility of over-engineering a seal and incurring unnecessary
Brake systems and components in automotive manufacturing
uses EPDM as a material of choice for sealing applications. Ethylene-propylene
compounds gives reliable performance under conditions of elevated
temperature, and they are highly resilient to exposure to corrosive
media like greases and mild acids, alcohols, alkali substances and
3) Viton (Fluorocarbon)
Fluorocarbon (FKM) seals are characterized
by their high performance for sealing applications where exposure to
ultraviolet degradation, ozone and weathering is expected. FKM material
also has desirable properties like low compression set and low volume
swell, which are critical factors to consider in join seal design.
Volume swell is the change in volume of a material as a result of
absorption of chemical fluid into the sealing component, and the effect
is more pronounced when the seal is subject to high pressure. Volume
swell will adversely affect the properties of the sealing material, and
can cause extrusion of the material. FKM material is commonly found in
applications in the aircraft industries, oilfield equipment
manufacturing and petrochemicals industries.
Temperature extremes, chemical corrosiveness, ozone and
UV resistance and mechanical properties like low compression set and gas
permeability resistance are the advantages of using fluorocarbon or FKM
seals. Because of its versatility, Viton is a commonly specified
material for use in an extensive range of applications. Industries where
FKM is used include, but are not limited to, that of the aerospace, oil
and gas, petrochemicals and more.
4) FFKM Perfluoroelastomers
The high-end in sealing technology with the most
demanding in performance criteria is perhaps found in semiconductor chip
manufacturing. Seals and o-rings come into contact, or are exposed to
highly aggressive chemicals. In addition, temperature extremes
encountered in the production subject seal parts to excessive abuse.
Perfluoroelastomers is the ultimate compound that satisfies the
requirements in such harsh working conditions.
The top of the range elastomeric material
which is used for sealing applications in the most severe and demanding
environments during manufacturing processes is perfluoroelastomers (FFKM).
Perfluoroelastomers are used where no other elastomeric material will do
the job. Extreme heat and contact with harsh chemical media are
conditions that are common in oilfield applications and semiconductor
processes. The ability to resist rapid gas decompression (RGD), also
known as explosive decompression, is unique in perfluoroelastomers due
to its high resilience and durability. Explosive decompression is a
phenomena commonly found in oil and gas extraction processes, where the
sudden release of high pressure gases or liquefied gases causes the
expelling of absorbed gases within the elastomeric seals and o-rings, in
a manner which damages the seal. Perfluoroelastomers are also specified
for their exceptional ability to withstand extreme thermal and chemical
Rubber Components and Seals in Automotive Manufacturing
Since 1981, Gmors has been manufacturing o-rings of
various sizes. rubber parts, seals and gaskets for the automotive
industry. Applications are found in vehicle transmissions, air
conditioning systems, brake and steering systems, clutch assemblies,
engine gaskets, fuel and cooling systems seals and numerous other
Selecting the Right Elastomer for Your Application
The expected service environment is an important criteria in the
selection of elastomeric seals. The following are important criteria to
consider, but please contact our material specialists for free
1. Types of fuel to be sealed and the expected contaminants and
2. Thermal conditions including highs and lows, and anticipated
excursions to elevated temperatures.
3. Operating pressures including highs and lows, and rates of
compression and decompression.
4. Static or dynamic application, and whether motion is rotary or
5. O-ring sizes and tolerance within groove.
Cost effectiveness is a major consideration in selecting the right seal.
An over-engineered seal that outperforms its corresponding parts or has
a service life beyond its warranty period may add unnecessary costs to
overall production. Generally, EPDM suffice for most typical
applications where seals come into contact with heat and steam, but may
not be suitable for applications at higher temperatures and when contact
with corrosive fluids is expected. Unscheduled maintenance can be
avoided along with costs savings because maintenance cost typically far
outweighs the initial cost of the seal.
Automotive Powertrain Gaskets and Seals
Emissions control, extended periods of warranty as well as elevated
service temperatures all leads to greater demands on the performance of
elastomeric seals in engines and powertrain systems. Engines that run at
higher temperatures along with aggressive lubricants all have
deleterious effects on elastomeric materials.
Transmission systems in
cars makes use of a combination of seals and o-ring
sizes of various dimensions because their operation involves a
complex set of movements. Gmors manufactures seals for automatic
transmissions with reliability and durability meeting the performance
criteria of vehicle drivetrains. The goal of automotive manufacturers is
to achieve maintenance free drivetrain systems that fulfill a zero
leakage requirement while working at high efficiencies.
Seal products used in
automatic transmission include elastomeric parts like o-rings, lip
seals, seals for fuel injectors and others. The ability to perform under
different chemical environments at elevated temperatures without
deterioration of physical properties is expected throughout the service
life of the vehicle.
Various sizes of o-rings and seals are used in the sealing of
hydraulic rams, turning shafts and reciprocating rods for power steering
applications subject to continuous abrasion. Sealing parts like
reciprocating seals must resist constant wear and withstand high
pressure in the hydraulic system during power steering operation.
designs and manufactures all sizes of o-rings
and seals for the automotive industries to withstand a variety of fluid
exposures under required operating temperatures. Important performance
criteria like compression set, volume swell and abrasion resistance are
all factored into the design.
for o-rings used in automotive applications may be specified for
pressures up to 2000 psi, and temperature variation in the range of -40C
to 200C. Contact fluids may be in the form of coolants, brake fluids,
refrigerant, engine and compressor oil, transmission and power steering
Seals and gaskets
(FKM) fluoroelastomer is the preferred compound for the manufacturing of
automotive engine seals, gaskets
and o-rings sizes of varies dimensions because
of its outstanding ability to maintain stability at high temperatures.
Gmors produces seals and gaskets made from Viton® for use in car fuel
injection and fuel pump applications. Rubber products that are custom
molded to precise specification are also offered.