The IX Seal Rings are designed and used where the NORSOK CFC (Compact Flange Connections);
The IX Seal Rings made from three different steels;
The IX Seal coating with PTFE by different colors.
Flange IX Seal Rings
Many clients have drawn on norton`s specialized knowledge and experience on the use of high pressure and high temperature metal-to-metal static sealing. norton 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.
The designed or materials shall be selected, so that main sealing areas 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:
Flange Material | Service Temp. | Seal Ring Material | Seal Ring PTFE Color |
Carbon Steel | -50oC to +250oC | CS,316L,Low Alloy Steel (AISI4140) | Blue |
Stainless Steel | -50oC to +250oC | 22Cr Duplex | Yellow |
Stainless Steel | -50oC to +250oC | 17/4-PH | Orange |
Stainless Steel | -101oC to +250oC | Nickel Alloys (Inconel 625 etc) | Black |
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 seal rings surfaces shall be machined with maximum surface roughness in accordance with below table:
Location | Ra max μm |
Sealing Faces | 0,8 |
All other Surfaces | 6,3 |
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 heel 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.
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 level 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.
Size & Weight:
The IX Rings only have one dimension per DN (Nominal Diameter) that covers all the pressure classes
DN | NPS | IX Dimension | Weight (kg) |
15 | 1/2″ | IX15 | 0.02 |
20 | 3/4″ | IX20 | 0.03 |
25 | 1″ | IX25 | 0.03 |
40 | 1 1/2″ | IX40 | 0.05 |
50 | 2″ | IX50 | 0.08 |
65 | 2 1/2″ | IX65 | 0.12 |
80 | 3″ | IX80 | 0.17 |
100 | 4″ | IX100 | 0.28 |
125 | 5″ | IX125 | 0.42 |
150 | 6″ | IX150 | 0.62 |
200 | 8″ | IX200 | 0.99 |
250 | 10″ | IX250 | 1.85 |
300 | 12″ | IX300 | 2.18 |
350 | 14″ | IX350 | 2.60 |
400 | 16″ | IX400 | 3.43 |
450 | 18″ | IX450 | 4.38 |
500 | 20″ | IX500 | 5.27 |
550 | 22″ | IX550 | 6.48 |
600 | 24″ | IX600 | 7.55 |
650 | 26″ | IX650 | 8.74 |
700 | 28″ | IX700 | 10.40 |
750 | 30″ | IX750 | 11.80 |
800 | 32″ | IX800 | 13.30 |
850 | 34″ | IX850 | 14.80 |
900 | 36″ | IX900 | 17.10 |
950 | 38″ | IX950 | 18.90 |
1000 | 40″ | IX1000 | 20.90 |
1050 | 42″ | IX1050 | 23.00 |
1100 | 44″ | IX1100 | 25.10 |
1150 | 46″ | IX1150 | 27.50 |
1200 | 48″ | IX1200 | 29.90 |
Features:
> Size form 10mm to 1700mm currently in service;
> The higher the pressure the more attractive the norton 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;
> 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.