What Are NBR Rings And How Can They Be Used

What Are NBR Rings
And How Can They Be
Used?

When you talk about O-rings, they are doughnutshaped
rings or a loop of elastomer that has a round
cross-section. Their main purpose is to create a seal
at the interface and they are designed in a way that
can be seated in a groove and be compressed
during assembly between the two parts.
Can be used in Static & Dynamic
applications
An O-ring may be used in static applications, where
there is no movement between the interfaces. They
can also be used for dynamic applications where
there is a relative motion between the parts and the
O-ring. For instance, you may find these NBR O-
rings being used in rotating pump shafts and also
hydraulic cylinder pistons.
These rings can be manufactured easily and they
are inexpensive, reliable and can be mounted easily
and that is why most common seals are used in the
design of the machines.

NBR (Nitrile rubber) is the general term given to
Acrylonitrile Butadiene Copolymer. These are the
most economical form of economical elastomer.
These rings gave the great quality of resisting to
petroleum-based oils and fuels. Whether they are
silicone greases, or hydraulic fluids or water and
alcohols they can be used with it.
It offers many desirable properties which include a
low compression set, has the high tensile strength
and also offer a high level of abrasion resistance.
Design of O-ring requires mechanical mounting that
applies a predictable deformation to the ring. It
means that there is a calculated stress at the
surface of the O-ring. The ring doesn’t leak till the
time the pressure of the fluid that is contained is
not exceeding the contacting stress.
The seal is designed to have a contact point
between the O-ring and the various sealing faces. It
means there is high local stress which is able to
tackle high pressure without passing the yield stress
of the O-ring body. As the rings are flexible as well

so they can handle the imperfections in the
mounting parts.
Sizes
These rings are available in various sizes. The SAE is
the body that provides the specifications for the
inside diameters, cross-sections, tolerances and the
size identification codes. The dimensions are
measured in
Internal Dimension (ID)
Outer Dimension(OD)
Thickness and Cross-Section (CS)
Finally,
NBR O-rings are known for their good mechanical
properties and their resistance to lubricants,
greases, and lower costs.