METAL JACKETED
GASKETS
Metal-plastic gaskets, also called double-jacketed gaskets, consist of a metal jacket and a soft material filler.
The sealing filler provides excellent resilience, while the metal coating (or jacket) protects against pressure, temperature fluctuations and corrosion.
They are useful in a variety of applications. Especially in heat exchanger equipment.
“High pressure suitability and blow out resistance”
- Proven sealing elements for use in apparatus construction, heat exchanger applications, pumps or valves.
- Fabricated to customer’s specification, with pass partition bars when needed.
- Graphite layers on both sides for use where the gasket sealing area is not perfect.
- Soft Iron, SS304L, SS316L and others available..
- Oval, rectangular or other shapes on request.
- The filler material gives the gasket resilience, while the metal jacket resists pressures, temperatures and corrosion.
Materials for metal-plastic gaskets
- Coating (jacket or envelope):
- Copper
- Stainless Steel
- Carbon Steel
- Brass
- Monel
- Others: Nickel, Aluminium, Titanium, Hastelloy, Incoloy, Silver, etc.
- Filler:
- PTFE
- Asbestos-free fibre
Profiles and values
| Profile | Section | Material | KO | K1 | RZ * |
| [N/mm] | [mm] | (µm) | |||
|
FW3 F3 F4 |
|
Al | 50 bD | 1,4 bD | 25 a 50 |
| F6 |  |
Cu | 60 bD | 1,6 bD | 12,5 a 25 |
| F8 |  |
Ni | 70 bD | 1,8 bD | 6,3 a 12,5 |
| F10 |  |
CrNi – Steel | 100 bD | 2,0bD | 2,5 a 6,3 |
| F12 |  |
||||
| F17 |  |
Steel | 60 bD | 1,6 bD | 12,5 a 25 |
* Recommended surface roughness of flange sealing surfaces
Surface pressure
Metal-plastic seals are seals with a metal-to-metal contact surface. This results in relatively high minimum sealing forces. The table of minimum min (joint closure) and maximum max (breaking limit) stresses for metal-plastic joints is given below:
|
Profile |
Material |
Surface pressure (N/mm2) | |||
| T = 20ºC | T = 300ºC | ||||
| smin | smáx | smin | smáx | ||
| F2 a F7 | Carbon Steel/A.F. Nickel/A.F.E |
70 | 180 | 80 | 150 |
| Steel | 100 | 250 | 115 |
200 |
|
|
Copper/A.F. Brass/A.F. |
60 | 150 | 70 | 120 | |
| Aluminium/A.F. | 30 | 100 | 40 | -60 | |
Features and details
When installing the metal-plastic seal in the device, the arrangement of the housing and the cover in the tongue and groove socket must be taken into account. Accordingly, the shell side should be installed towards the male and the cover side towards the socket (female); otherwise the seal may be irreversibly damaged by premature collapse of the cover.
Metal-plastic gaskets with ribs
Sometimes it is desired that the metal-plastic gasket be without ribs (one-piece gasket); in this particular case the minimum radius of connection of the rib to the ring is r = 10 mm.
It has been widely demonstrated that manufacturing with welded ribs is more economical and technically better (better sealing), since in this case there is a double sealing line as opposed to the construction of the one-piece joint, which only has one sealing line.
Different configurations and models
