Flange IX Seal Rings

Many clients have drawn on SUNWELL`s specialized knowledge and experience on the use of high pressure and high temperature metal-to-metal static sealing. SUNWELL have developed a sealing system which uses a modified cone ring giving excellent leak tightness properties under the most severe conditions of pressure, temperature, thermal cycling and shock.

IX Seal Rings are designed and used where NORSOK CFC (Compact Flange Connections) are in use. The rings come in three different kinds of steel and are coated with PTFE in varying colors in order to distinguish between them

The designed or materials shall be selected, so that main sealing ares can not be subject to corrosion.

Typical Seal Ring Materials

Typical minimum yield stress and ultimate stress of the seal ring material shall at maximum design temperature be 300MPa and 360MPa, respectively, in order to allow for reasonably elastic spring-back.

Lower strength may be used, but is not recommended.

The user is responsible for selecting a seal ring material which is suitable for the service medium and the design temperature conditions.

Seal ring materials are commonly chosen to be compatible with the flange material, I.e. Duplex seal ring in duplex flange.

IX Seal Ring Selection

Coating

IX Seal Rings shall be coated with 10μm to 30μm PTFE coating. The colour of the coating shall follow the requirement above table.

Surface Finish

All sea rings surfaces shall be machined with maximum surface roughness in accordance with below table:

How IX Ring Seal Works

IX Seal Ring axial forces are exerted on the taper of the metal seal ring and translated into a radial sealing force.

Furthermore with increased pre-load, the bevel is closed and face to face contact is achieved at the outer wedge while most of the bolt pre-load is transferred as compressive forces between the flange faces at the heel.

There are two independent seals. The first seal is created by application of seal seating stress at the flange heel. The flange also remains in contact along it`s outer circumference at the flange faces for all allowable load levels. The main seal is the IX Seal Ring. The seal ring force is provided by the elastic stored energy in the stressed seal ring. Any hell leakage will give intemal pressure acting on the seal ring inside intensifying the sealing action.

The design aims at preventing exposure to oxygen and other corrosive agents. Thus, this prevents corrosion of the flange faces, the stressed length of the bolts and the seal ring.

IX Seal Ring Installation

Size & Weight

The IX Rings only have one dimension per DN (Nominal Diameter) that covers all the pressure classes

Features

>Size form 10mm to 1700mm currently in service;

>The higher the pressure the more attractive the SUNWELL design becomes as internal pressure intensifies the sealing action;

>IX seal ring can be at high temperatures. Maximum service temperature being limited by the seal material selected. Materials range from carbon and alloy steel through to inconel, with a range of coating for lubrication;

>The sealing system is extremely leak tight under the most severe conditions of pressure, temperature, vacuum, and is suitable for nuclear applications;

>Cold quench conditions and thermal cycling are the cause of most leakage problems where conventional compressible type joints and seal materials are used. The additional flexibility of the IX Seal Ring ensures a tight seal during thermal transient conditions;

>compact and lighter flange designs can usually be achieved by using IX Seal Rings. Fluid seal areas and joint loads are lower when compared with conventional compressible type joints;/p>

>The all IX Seal Ring is elastic in design and on dismantling reverts to its original form ready for re-use. All seals of a given size are interchangeable without any pre-fitting./p>