About Hydraulic Seals and Hydraulic Seal Manufacturers Including: Lip
Seal, Mechanical
Seals, Metric
Oil Seals, Oil Seals & Rubber
Seals.
A seal is a ring-shaped component that is designed
to prohibit or limit the leakage of fluid from a device. Various types
of seals are used in applications that have constantly moving equipment,
such as the rotating or reciprocating shafts and cylinders that are an
essential part of hydraulic and pneumatic systems. Devices that use seals
include hydraulic rams and mixers, brake devices, valves, clean
rooms, conveyors and
test equipment. Hydraulic seal manufacturers generally make their products
from are rubber or metal, and in some cases leather or felt. Some of
the rubber materials used to create seals are nitrile, silicone, natural
rubber, butyl and styrene butadiene. Additionally, quite a few hydraulic
seal manufacturers use their own unique materials that they have specially
developed for their products.
Different kinds of hydraulic seals exist for numerous purposes and applications.
Oil seals are common hydraulic seals. They are used to retain oil and
other lubricants in rotary applications and prevent leaks. Many of these
operate with a flexible lip that rubs against the shaft or housing to
provide a tight seal against leakage. Mechanical
seals are used in applications
that have a rotating shaft under a state of high pressure, temperature
and speed. These hydraulic seals are used to prohibit fluid leakage
for such mechanisms as agitators, pumps, mixers and cryogenic seals.
Hydraulic seal manufacturers create many products that are application
specific and specially designed to prevent leaks under very particular
circumstances.
The distinctive types of sealing positions and directions that are used
for hydraulic and pneumatic seals are axial seal, rod or internal seal,
external or symmetric seal, or piston. The sealing direction is instrumental
for hydraulic seals and pneumatic seals in mechanisms that use axial
movement, such as cylinders and pistons. Because the action may be single
or double, a seal can be used for one or two directions. One of these
types, the rod seal, is radial and is press fitted into the housing
bore. Another, the axial seal, has the function to axially seal an adjoining
housing or other mechanical component.
When purchasing hydraulic seals, there are some important factors to
consider, such as the diameter of the housing bore and the inner or
outer seal, the dimension of the outer shaft and the axial or radial
cross section needed for the application. Also, keep in mind certain
operating parameters like the working temperature, vacuum rating and
highest working speed and pressure. There are many types of hydraulic
seals for different uses in industries. Some of the particular industries
that make use of these seals include medical and pharmaceutical, waste
disposal, aerospace, marine, food and chemical processing, automotive,
military, nuclear and pulp and paper mills.
Types of Hydraulic Seals
-
are seals that are designed to reduce the effects of hydraulic pressure
in the seal compartment.
-
use a formed or welded bellows to supply a secondary sealing and spring
loading.
- uniformly seal in response to pressure from both directions.
Bidirectional pressure seals are also known as "double balanced
seals" or "reversible balanced seals."
-
stop leakage past components that are in relative motion.
- are
a type of bearing seal used in place of oil seals to supply greater
reliability.
- are
versatile and high-performance seals used for uniform, low-pressure
sealing.
-
prohibit fluid leakage around the rotating shaft in a state of extreme
pressure, temperature and shaft speed. Typical uses for mechanical seals
are for agitators, pumps, mixers and cryogenic seals.
- are available in a wide variety of sizes, all measured in metric units.
- are seals with flexible lips that when placed to a housing
or shaft prohibit the escape of fluids or prevent contaminants from
entering. Certain grease and oil seals are equipped with a spring to
aid in maintaining contact of the seal with the shaft.
-
are sealing rings that have a circular cross section that is either
solid or hollow.
-
are seals that are made from rubber materials, such as nitrile, viton,
natural rubber and hypalon, among others.
-
are seals that have been made from Teflon® or are coated with Teflon®.
Teflon® is a plastic material that supplies improved lubrication
properties, resistance to wear and added strength.
Hydraulic Seals Terms
- The surface loss of a material caused
by friction.
- A material's resistance to the surface
loss caused by frictional forces.
- A state in which two surface are bonded together through
interfacial forces.
- Motion along an axis or parallel to the center
line of a shaft.
- A component made from corrugated plastic or rubber around
a shaft that has the ability to stretch.
- A list of all materials needed to manufacture
a certain product.
- A change of appearance in rubber, resulting from a solid
or liquid material moving towards the surface. Bloom resembles surface
dust.
- The tendency of a material to crack under deformation.
- A material's property
of being able to conduct/transmit electricity.
- The view of an o-ring when cut at a right angle
to the axis, which shows its interior construction.
- Used in a hydraulic or pneumatic cylinder to exclude
or scrape the rod clean.
- A material's ability
to move in a mold during the molding process.
- The resistance to motion when two surfaces are in contact.
- Occurs when a material's
surface reacts with oxygen, usually causing a change in the appearance
or texture of the surface.
- A conical rubber component pressed into a hole or tube to
finalize a seal.
- The measure of small holes in a material.
- A material's ability
of returning to its original state after deformation.
- The tendency of a material to contract while cooling.
- A ring with flat sides to provide specific dimensional
spacing between two components.
- The resistance of a material to flow under stress.
- Round, flat rings used as spacers, gaskets or slip devices
under the head of a bolt.