The Perfect O-Ring for Any Application
O-rings are among the most versatile, dependable, and inexpensive seals available. O-Rings provide a number of unique advantages over other seals, including:
- A circular cross-section with a minimal surface area, enhancing their resistance to abrasion, fluids, adverse environments, and mechanical damage.
- This cross-section also makes them adaptable to various types of squeeze, including axial, radial, and angular.
- They seal in both directions.
- They fit into confined spaces without bulky, adjustable, or expensive support structures.
- Easy to maintain: there are no bolts to re-tighten.
For these reasons, O-rings are the best choice for a wide variety of applications.
Static Seal
A static seal application refers to a gland in which there is very little motion between the parts of the gland which come in contact with the O-ring. Small amounts of motion – such as thermal expansion, vibration, bolt stretch, and O-ring response to fluid pressure – do not change the definition of a static application. Static applications are divided into two types based on the direction of squeeze applied to the O-ring cross-section: axial and radial. In some cases, both types of squeeze are present, though this is not recommended since it prevents the O-ring from expanding.
Static Axial Seals
A static axial seal applies pressure on the top and bottom of an O-ring. Static axial seals are most often used in face seal applications. Another common type of application in this category involves an O-ring on the face of one part of a structure, which closes on another structure. As the structures close on each another, a sealing action compresses the O-ring between the mating surfaces.
Static Radial Seals
In a static radial seal, there is squeeze between the inside diameter and outside diameter of the O-ring. Common static radial seals include cap seals and plug seals. Although seals are best left on one side of the seal, O-rings are versatile enough to work in grooves of many different shapes and directions of squeeze. One example is a crush seal, in which the O-ring is installed on a triangular gland with very little space surrounding it.
Due to potential damage during installation, as well as the potential for warping in the metal gland, this application is only used where cost and ease of machining are the most important factors.
Dynamic Seals
Dynamic sealing applications involve relative movement between the parts of the gland. O-rings in these applications must be able to withstand the friction caused by the sliding action against the gland. This factor makes dynamic seal applications somewhat more difficult to design. In many dynamic sealing applications, O-rings are subjected to radical squeeze, reciprocating intermittent or continuous motion, or intermittent rotary or oscillating motion.
Reciprocating Seals
In a reciprocating seal application, a back and forth motion along the shaft axis between the inner and outer elements of the gland occurs in what is called a piston and rod seal.
Oscillating Seals
The inner and outer members of a gland move in an arc around the axis of a shaft in alternating directions (typically at an intermittent rate). They are most often found in faucet valves, but may be found in any other types of valves since they are simple to design and reduce costs.
Other Dynamic Seals
O-rings can be used in any application where data used for reciprocating or oscillating seals do not apply. Their versatility allows them to be used in many rotary applications where either the inner and outer members of the gland continuously turn around the axis of the shaft.
Rotary Applications
Rotary seals involve an inner and outer member of a sealing element turning around a shaft axis in one direction. The name applies to any application where the rotation is reversible, but not when the motion is intermittent (such an application is an oscillating seal). In such an application, heat from friction is continuously generated in one place. Thus, the main concern in a rotary application is using a seal which can withstand high temperatures and to reduce heat buildup as much as possible.
Other Applications
Rubber seals can be used in many other applications not listed here, including seat seals, pneumatic seals, and vacuum seals.
Whether you need a seal for a simple static application, or a more durable seal for a rotary application, Real Seal will have a rubber seal suitable for your application. We are also one of the few seal suppliers that have a full-time chemist to answer any questions you might have, and ensure that you have the perfect seal for your application. Don’t hesitate to give us a call today.
