Do corrugated metal gaskets need cleaning?

1. Why is it necessary to clean corrugated metal gaskets?

Old gasket residue on the mating surface creates uneven support, preventing the new gasket from fitting smoothly and causing leaks.

Hard particles (such as metal shavings and welding slag) embedded in the gasket's soft metal surface (such as soft aluminum or copper) or trapped between the mating surfaces can scratch the gasket and flange surfaces, compromising the integrity of the seal.

Preventing cross-contamination:
In the chemical, food, and pharmaceutical industries, mixing of different process media through residual gasket residue can lead to product contamination, catalyst poisoning, or unintended chemical reactions.

Facilitating inspection and reuse:
Only by thorough cleaning can a removed gasket be effectively inspected to determine if it is deformed, dented, or corroded, thereby determining whether it can be reused in non-critical applications.

Clean gaskets also facilitate final inspection before installation.

2. How to properly clean corrugated metal gaskets?

Cleaning requires extreme care, as incorrect cleaning methods are more harmful than not cleaning at all, and can easily damage the delicate corrugated structure of the gasket and the soft coating on its surface.

(1). When to clean

Every time the flange is disassembled, cleaning must be performed, regardless of whether the gasket is planned to be reused.

Before installing a new gasket, ensure that the flange mating surface and the gasket itself are clean and oil-free.

(2). Cleaning steps and methods

Safety first: Ensure that the system has been fully depressurized, cooled, and that strict isolation and lockout procedures have been implemented.

Removing the old gasket:
Use a plastic or wooden scraper (such as a nylon scraper) to carefully scrape off most of the gasket debris. Do not use hard metal tools such as screwdrivers, chisels, and wire brushes, as they will severely scratch the expensive flange sealing surface.
For firmly adhered adhesive residues, you can use a special gasket remover spray and wait for it to soften before scraping it off.

Cleaning the flange sealing surface:
This is the most critical step. Use a lint-free cloth dampened with acetone, isopropyl alcohol, or a specialized solvent to thoroughly wipe the flange sealing surface until no traces remain.

Inspect the sealing surface: Gently run your fingernail or a plastic sheet across the surface to feel for raised scratches or indentations. If severe damage is found, repair or replace the flange.

Cleaning the removed gasket (if planning to inspect or reuse it):
Soak and scrub: Soak the gasket in a container of the aforementioned solvent. Gently scrub the corrugated crevices and inner and outer edges with a soft-bristled brush (such as an old toothbrush).

Blow-dry: Use dry, oil-free compressed air to blow through the gasket from all angles to ensure that the solvent and all small particles are removed.

Inspect: Carefully examine the gasket under light for any flatness deviations, cracks, signs of excessive compression (flattening), or corrosion. If in doubt, it's best to replace the gasket.

3. Cleaning Precautions and Don'ts

Do not use electric wire wheels or angle grinders to clean the flange surface, as this will irreversibly damage the finished surface. Use solvents with caution: Ensure that the solvent is compatible with the system media and the gasket material (for example, some rubber coatings may be dissolved by strong solvents). Work in a well-ventilated area and wear chemical-resistant gloves and safety glasses.
Protect gaskets: When handling and cleaning gaskets, avoid bending, twisting, or dropping them to prevent altering their flatness.