A short-circuit cell (galvanic cell) is formed in which the electrodes are made of the two coupled materials.
A flow of electrons is generated from the oxidizing metal with a lower potential (anode or negative pole) to the reducing metal with a higher potential (cathode or positive pole).
A direct current flows from the cathode to the anode area, causing corrosion of the materials.
The electrical conductivity of an aggressive environment is a key factor that directly influences the contact corrosion process. In high conductivity environments, this means that the attack is intense and spreads its effect over large distances, while in environments with high resistance to oxidation, the corrosion effect is limited to the anode area near the junction with the cathode.
For this reason, this type of corrosion is particularly severe in seawater, but not as severe in freshwater, which has a conductivity at least two orders of magnitude lower.
Insulating the two metals with the VR Insulation KIT (Flange Insulation Kit) helps prevent or control contact corrosion.
The VR Insulation Kit prevents galvanic corrosion by ensuring electrical continuity between adjacent flanges is interrupted and insulating each component without interfering with proper tightening.
| CHARACTERISTICS INSULATING SLEEVES AND WASHERS | ||
|---|---|---|
| Sleeves G10 | Washers LTBF | |
| Body length | 15 KV/mm | 10 KV/mm |
| Electrical Resistance | 10e11Ω | 10e09Ω |
| Water Absorbency | 0,4% | 0,4% |
| MAX temperatures | 150°C | 150°C |
| GASKET TECHNICAL DATA SHEET | |||||
|---|---|---|---|---|---|
| Coating phenolic resin | Neoprene | EPDM | PTFE C.V. | PRFE Modified | |
| Pressure MAX | It depends on the covering | — | — | 60 bar | 80 bar |
| Operating temperature range | -50°C ; 180°C | 0°C ; 80°C | -30°C ; 120°C | -200°C ; 260°C | -200°C ; 260°C |
| M | It depends on the covering | 1 | 1 | 2.75 | 2.75 |
| Y | It depends on the covering | 1.40 MPa | 1.40 MPa | 25 MPa | 25 MPa |
| PH range | — | — | — | 0 ; 14 | 0 ; 14 |
| Dielectric strength | 10KV/mm | 30KV/mm | 40KV/mm | 65KV/mm | 65KV/mm |
| Volume electrical resistance | 10e16Ω | 10e13Ω | 10e13Ω | 10e16Ω | 10e16Ω |
The Inside Bolt Circle Isolation Kit uses a center gasket that locates inside the bolts. The gasket's outer diameter fits snugly into place, ensuring a well-centered position. The illustration clearly shows how the opposing flanges are completely isolated from each other. For use on full-face and raised-face flanges.
Full-face insulation kits are suitable for both flat-face and raised-face flanges. This assembly minimizes the ingress of conductive foreign matter between the flange parts on the outside of the raised faces and reduces the risk of bridging. The illustration clearly shows how the opposing flanges are completely insulated from each other. For use on full-face and raised-face flanges.
Ring Joint Insulation Kits include an oval insulating ring joint gasket and are suitable for standard RTJ flanges, the illustration clearly shows how the opposing flanges are totally insulated from each other, for use on standard ring joint flanges
The kit consists of a gasket made with insulating materials suitable for the specific use, an insulating sleeve for each bolt, a pair of insulating and metal washers for each hut.
Our kit consists of a gasket made with insulating materials suitable for the specific application and an insulating sleeve for each bolt. By inserting the sleeves into the flange holes between the bolt, nuts, and metal washers, electrical insulation is ensured.
20092 Cinisello Balsamo (MI), Via dei lavoratori, 15-19
