Metal face seal groups most severe conditions ( in very abrasive conditions such as dust, sand, soil, stone, mud ) even without maintenance , should be long lasting , motion bearings definite protect , however bearings lubricated and the oil necessary for cooling of the bearings sealed.
Metal face seal groups properties;
- Corrosion-resistant sealing rings,
- Precision lapping , self-renewing sealing surfaces,
- Minimum surface load variations,
- Special sea land elastomer load ring materials to match application requirements
Rotating speed, lubrication , temperature and differential pressure are factors to consider when determining seal face loads.
Metsan seal group consists of wear-resistant two elastomer load rings and two metal rings made from special alloy casting.The metal rings should be minimum 57 HRC hardened, surfaces grinded, lapped and cleaned ultrasonically. The sealing rings one fixed and the other rotates with housing is placed.
The technology used in the production of metal face seal groups consists of special machinery and equipments. Each stage of production process are carried out in our company. Metal Face Seal Groups’ manufacturing work flow is given below;
WORKFLOW SCHEME
Elastomer load rings used in Metsan Seal Group has three tasks;
- The load ring in dynamic housing transmits the moment of housing to the metal sealing ring.
- They provide the sealing through their contact surfaces between housings and metal rings.
- Provide axial pressure
Material of elastomer load rings varies according to the application temperature. The appropriate materials for the specified operating temperatures are shown below:
MATERİAL OF ELASTOMER LOAD RINGS (TORIC RINGS)
NITRILE (NBR)
Nitrile is recommended most applications of seals to use. NBR is compatible with most mineral based lubricant oil .Nitrile o-ring shows the maximum resistance against abrasion. Nitrile is recommended for temperatures ranging from -25°C to 100°C.
LT NITRILE ( LOW TEMPERATURE)
Low temperature nitrile was specifically developed for highly abrasive , low temperature applications. Low temperature nitrile is recommended for temperatures ranging from -50°Cto 105°C.
SILICONE (MVQ)
Silicone is recommended for temperatures ranging from -60°C to +165°C. Not recommended for use in dynamic applications. Silicone has a good resistance against ozone, air and oils. It is not compatible with fuels or certain types of gear lubricants. Silicone also has inferior abrasion resistance to nitrile. Typically preferred silicone is extreme high or extreme low temperature applications.
VITON (FKM)
Viton is recommended for temperature ranging from-10°C to 190°C.Viton is typically used in applications where extremely high temperatures are a concern. Viton has a good resistance against most chemicals. Viton has very poor low temperature capability and will harden at temperatures approaching freezing.
HNBR ( HYDROGENATED NITRILE)
HNBR is a nitrile-based material recommended for temperature ranging from 40°C to 135°C. It has very similar abrasion resistance characteristics to standard nitrile, but HNBR has better resistance to compression set ( permanent deformation) when exposed to high temperatures for extended periods of time.
| NİTRİLE (NBR) | LT NİTRİLE (LT NBR) | SİLİCONE (MVQ) | VİTON (FKM) | HNBR | |
| TENSILE RESISTANCE | MEDIUM | MEDIUM | LOW | MEDIUM | MEDIUM |
| ABRASION RESISTANCE | VERY GOOD | VERY GOOD | WEAK | MEDIUM | VERY GOOD |
| BREAKING EXPANSION | VERY GOOD | VERY GOOD | MEDİUM | GOOD | VERY GOOD |
| OIL RESISTANCE | VERY GOOD | VERY GOOD | WEAK | GOOD | VERY GOOD |
| TEAR RESISTANCE | GOOD | GOOD | WEAK | GOOD | GOOD |
| HOT WATER RESISTANCE | GOOD | GOOD | LOW | VERY GOOD | GOOD |
| MİN. ÇALIŞMA SICAKLIĞI | – 25 °C | – 50 °C | – 60 °C | – 10 °C | – 40 °C |
| MAX. ÇALIŞMA SICAKLIĞI | + 100 °C | + 105 °C | + 165 °C | +190 °C | + 135 °C |
The most effective cause that decreases the life of the seal is the wear on contact faces of the metal rings. These cond cause is the permanent deformation of load rings that results in the loss of static axial load. When selecting the load ring material, this matter should be noticed carefully. Metsan uses special alloy casting material to produce high wear resistant seal groups.
When these all groups are being dismantled during maintenance or revision, and even if the wear on sealing surfaces of the rings didn’t reach the limit region, the seal group must be changed with a new one. Because, the sealing surfaces of metal rings which are oriented to each other during operation, may not provide the same harmony and may cause oil leak age while running after remounting .
METAL FACE SEALGROUP APPLICATIONS
Undercarriage Systems of Tracked Vehicles
Asphalt Machines
Cement and Concrete Mixers
Conveyors
Loaders , Graders
Mixers and Grindingst in Ceramic Industry
Underground Excavators
Agricultural Machinery
Tunelling Machines
Pumps
Scrapers
Transportes
Trucks
Wagons
Railway Equipment
Military Vehicles ( Tanks)