CuNiFe products are used in many applications of the maritime area as these copper-nickel-iron alloys are highly resistant to sea water. Because of the high costs of this material, it is not economic to equip all areas with this type of material. Therefore this material should only be used in systems conveying sea water, such as sea water cooling circuits in equipment or difficult to access bilge discharges inside ships. In the long run, however, CuNiFe products used in sea water systems have a considerably longer life expectancy than those made of other materials.
The pipes used have to be connected according to the application requirements. To obtain a top-quality fitting which is cost-effective, Parker Ermeto designed the CuNiFe/stainless steel connection. As the salt water is enclosed completely inside the CuNiFe fitting, Parker can offer it with a stainless steel functional nut which is less expensive than a CuNiFe nut. Due to the design of the fitting, the seawater as the medium conveyed has no contact with the nut.
This solution is suitable for the application in dry areas, e.g. below deck. For applications in areas exposed to seawater, the CuNiFe / stainless steel combination without additional surface treatment is unsuitable because of the combination of materials. External influences would cause galvanic corrosion of the stainless steel and the CuNiFe alloy due to the seawater acting as an electrolyte.