Why new flanges rust before installation

Machined carbon and low-alloy steel surfaces are reactive when exposed to humidity, condensation, fingerprints, salts or acidic packaging. Ocean freight adds temperature cycling and salt-laden environments that can create condensation inside crates.

Rust on a noncritical exterior may be repairable, but corrosion or impact damage on gasket faces, RTJ grooves, bolt holes or weld preparations can cause rejection.

Preservation after final inspection

1. Remove machining fluid, abrasive residue and moisture.
2. Verify final marking and photograph the accepted condition.
3. Apply a compatible temporary rust preventive to permitted surfaces.
4. Install rigid protectors on sealing faces and weld ends.
5. Use VCI or barrier wrap and calculated desiccant where specified.
6. Seal the package and record preservation date and method.

Export packing and handling

Heavy flanges should be separated so faces cannot strike each other. Blocking and bracing must resist forklift, truck, port and vessel handling. Lifting points and gross weight should be marked clearly.

Wood packaging must satisfy destination phytosanitary requirements. Waterproof outer protection should not trap wet components inside an airtight package.

Warehouse and site storage

Store crates off the ground under cover and inspect for water ingress. Preserve identity by heat number and PO item. Use first-expiring preservation dates to plan reinspection and renewal.

Before installation, remove temporary coatings using an approved cleaner, inspect sealing faces and weld ends, and verify that no residue can affect gasket seating, welding or process cleanliness.