Encapsulated O-rings

What Are Encapsulated O-rings?

 The encapsulated O-rings are made of silicone rubber or fluororubber core and wrapped in an FEP or PFA outer shell.

Why Choose Encapsulated O-Rings?

This combination of a rubber's flexibility with a PTFE (Teflon) resistance to chemicals makes for strong, long-lasting O-rings. Encapsulated O-rings can handle extreme temperatures, chemicals, and wear and tear very well.

Characteristics of Encapsulated O-Rings:

• Very good resistance to nearly all media (exceptions are alkali metals and some fluorine compounds)

• Applications in a broad range of temperatures

• Superbly suited for use in the food, chemical, and pharmaceutical industries

• Low contamination

• Low permeation

• Low coefficient of friction prevents the stick-slip effect

• Cost-effective, high-performance seal for many critical application areas

Types of Encapsulated O-rings

FEP Encapsulation：

•Wide range of chemical resistance

•High corrosion resistance

•Low compression set

•Low coefficient of friction

•Temp range of -60°C to 205°C(-76°F to 400°F) (500°F short exposure)

PFA Encapsulation：

•All the benefits of FEP encapsulation

•Greater temperature resistance

•Greater mechanical strength

•Longer service life

•Greater cracking resistance

Solid core：

These are standard encapsulated O-rings that have either a silicone energizer or a core made from FKM, also known as Viton. Solid-core energizers provide the best resistance to compression set and recovery. 

Hollow core：

Hollow-core o-rings contain a circular gap within the energizer as a way to provide effective sealing for situations where a more flexible, easier-to-squeeze o-ring is required.

Ring Shape Options：

You can get non-standard ring shapes (like square, rectangular, or oval) if you contact us. This is possible if the ring is going to be used for a special job.

Encapsulated O-Ring Installation Guidelines:

The FEP/PFA encapsulation is a hard material with limited flexibility compared to the fully elastomeric O-ring inside. The encapsulation outer layer can be damaged during installation if it is stretched too much or if there are sharp edges on the part.

To ensure a successful installation, it is important to heat the O-rings beforehand and check that the installation surfaces are free from sharp edges.

Internal Sealing – The Housing Groove：

1. The seal must be deformed to fit into the housing
2. To facilitate assembly, place the O-ring in hot water for 10 minutes and install it into the groove immediately thereafter
3. To do this, push the forward edge of the ring out over the groove (Figure 1)
4. Carefully position the rear edge of the ring into the groove
5. Pull the front edge back until the ring snaps into the groove (Figure 2)
6. The rod should be pushed in, provided that the ring is still warm and deformable
7. The use of installation aids is an option

Outer Sealing – Groove on Shaft：

1. Use installation cone for assembly
2. Place O-ring into hot water for 10 minutes
3. Then, using the cone, press quickly and evenly until the ring snaps into the groove (Figure 3)
4. If necessary, compress the ring to its original dimensions using a second ring (applying pressure here)

Encapsulated O-Ring Heating Methods:

Hot Water (Recommended):

1. Heat water to 100°C / 212°F.
2. Place O-rings in water for a minimum of 3 minutes.
3. Remove the O-rings just prior to installing them.
4. If the o-rings become cool, reheat to installation is done while still warm.

Oven Heating:

1. Set oven to 100°C / 212°F (ensure no excessive temperature fluctuation).
2. Place o-rings evenly on the backing sheet.
3. Heat o-rings for a minimum of 15 minutes (no maximum time limit).
4. Install the O-ring immediately after removing it from the oven.
5. If the O-rings become cool, reheat to installation is done while still warm.