DESCRIPTION
Metal-jacketed gaskets are particularly suitable for sealing flat surfaces of heat exchangers, gas pipes, cast iron flanges, autoclaves and similar. The heat exchanger gaskets come in a wide range of types including single or double jacketed, corrugated, plain metal, soft and many others.
SHAPE AND CONSTRUCTION
These gaskets are used in shell and tube type heat exchangers. They can be manufactured in very different sizes, shapes, with or without bars. The primary seal is at inner diameter of the gasket, the outer gasket diameter acts as a secondary seal. The bars seal between the heat exchangers passages. The heat exchanger gaskets are produced in several types to meet the most demanding applications. Gaskets for heat exchangers can be manufactured in metal or alloy with a thickness of 0.4mm featuring a soft core inside a metallic jacket.
MATERIALS FOR HEAT EXCHANGER GASKETS
Selection of the jacket material depends on operating conditions. Materials for metallic jacket are as below:
Metallic jacket
| MATERIAL | ASTM | DIN MATERIAL NO |
| Low Carbon Steel | Soft Iron (CS) | 1.0333 |
| Stainless Steel | AISI 304 | 1.4301 |
| Stainless Steel | AISI 316, 316L | 1.4401, 1.4404 |
| Stainless Steel | AISI 321 | 1.4541 |
| Stainless Steel | AISI 316 Ti | 1.4571 |
| Monel (NiCu30Fe) | Alloy 400 | 2.4360 |
| Copper | Copper | 2.0090 |
| Brass | Brass Ms 63 | 2.0321 |
| Titanium | B 348 Gr. 1 | 3.7025 |
Metallic jacket is normally 0.4mm thick
Other materials are available on request
Filler
The standard filler material is flexible graphite. Other fillers like ceramic, mineral or other can also be used.
Sizes
The metal jacketed gaskets come in sizes according to EN 1514-4 and ASME B 16.20. Below table shows standard dimensions for these gaskets:
| STANDARD DIMENSIONS | |
| Gasket Thickness | 2-12mm |
| Gasket Width | 10,13 and 16mm |
| Bar Width | 8,10 and 13mm |
Tolerances
The tolerances of metal jacketed gaskets meet ASME B 16.20 and EN 1514-4. Manufacturing tolerances are as follows:
| MANUFACTURING TOLERANCES | ||
| Gasket Inside Diameter (mm) | Diameter Tolerance (mm) | |
| Inside Diameter | Outside Diameter | |
| Up to 150 | +0.8; -0.0 | +0.0; -0.8 |
| From 150 to 1500 | +1.6; -0.0 | +0.0; -1.6 |
| 1500 or greater | +2.4; -0.0 | +0.0; -2.4 |
METAL JACKETED GASKETS WITH INTEGRATED BARS
Double jacketed gaskets for heat exchangers are manufactured with integrated bars. There is a radius between bars and an internal diameter of the gasket. The values of the radius for the most commonly used metals and alloys are shown in the following table. If a radius is less than R min, the material can crack, reducing the sealing properties of the gaskets. Gasket materials can be seen in below table:
| GASKET MATERIALS AND R min | |
| Gasket Material | R min |
| Copper | 8mm |
| Soft Iron (CS) | 8mm |
| Brass, Monel | 10mm |
| Stainless Steel | 10mm |
