Why are corrugated metal gaskets irreplaceable under high temperature and high pressure conditions?

In the petrochemical, electric power, nuclear power and other industrial fields, high temperature and high pressure (HT/HP) working conditions have very strict requirements on the performance of seals. Ordinary gaskets are prone to failure under extreme conditions, resulting in medium leakage, equipment damage and even safety accidents. Metal Corrugated Gasket has become an irreplaceable choice under high temperature and high pressure conditions due to its unique structural design and material properties.

1. Material properties: high temperature resistance, high pressure resistance, corrosion resistance

High temperature resistance (-200℃~1000℃)

Corrugated metal gaskets are made of high-performance alloy materials and can withstand extreme temperatures:

Stainless steel (316/321): suitable for -200℃~600℃, resistant to general corrosion.

Inconel 600/625: temperature resistance up to 1000℃, resistant to hydrogen sulfide (H₂S) corrosion.

Hastelloy C-276: resistant to strong acids (such as hydrochloric acid, sulfuric acid) and high-temperature oxidation.

Comparison: Non-metallic gaskets (such as graphite, rubber) will carbonize or melt above 500℃, while ordinary metal flat gaskets are prone to creep deformation at high temperatures.

High pressure deformation resistance (＞50MPa)

Metal corrugated structure can elastically deform under high pressure to compensate for the slight unevenness of the flange surface and prevent sealing failure.

Creep resistance: The elastic recovery rate of corrugated gaskets is greater than 90%, while flat metal gaskets are prone to plastic deformation under high pressure, resulting in bolt loosening and leakage.

Corrosion resistance and media compatibility

Surface coating technology: PTFE (acid and alkali resistance), silver (enhanced thermal conductivity) or nickel (chloride ion corrosion resistance) can be plated.

Applicable media: acidic gas (CO₂, H₂S), strong alkali, liquid metal, etc.

Comparison: Rubber gaskets are prone to swelling when exposed to oil, and graphite gaskets are prone to powderization in a strong oxidizing environment.

2. Structural advantages: elastic compensation and high sealing performance

Corrugation elastic compensation mechanism

Corrugation peak-valley structure produces elastic deformation when under pressure, automatically adapting to the unevenness of the flange surface.

Rebound performance: Even if the bolt preload decreases, the corrugated structure can still maintain sealing (flat gaskets leak once they are loose).

Multi-layer composite design (enhanced gasket)

Inner metal corrugation + outer flexible graphite: both metal strength and non-metallic sealing.

Application scenario: main steam pipeline of nuclear power plant (needs to be resistant to high temperature and radiation at the same time).

Comparison: Flat metal gaskets cannot adapt to flange deformation and are prone to leakage due to local stress concentration.

Performance comparison with traditional gaskets：

3. Maintenance points of corrugated metal gasket

• Installation precautions

Inspection before installation

Gasket status: confirm that there are no indentations, cracks or corrosion (especially in the corrugated area).

Flange surface: clean and check flatness (roughness Ra≤0.8μm), no scratches or rust.

Bolts: use new bolts or confirm that there is no tensile deformation, and apply anti-seizure agent to the threads.

Correct installation steps

Center placement: The gasket must completely cover the flange sealing surface, and no deviation is allowed.

Preload control: cross-tighten in stages according to standard torque (such as the 50%-80%-100% three-step method recommended by ASME B16.5).

Avoid overpressure: Excessive torque may cause the corrugation to collapse (refer to the compression rate provided by the manufacturer, usually 30%-50%).

Prohibited behavior:

Reuse of flattened gaskets (elastic failure).

Use hammers or pneumatic tools to violently install.

• Disassembly and replacement standards

Situations where replacement is required

Corrugated structure damage: corrugation flattened, broken or partially collapsed (elastic loss).

Corrosion/wear: Pitting, cracks or large-scale shedding of coating can be seen on the metal substrate.

Leakage history: Repeated leakage at the same gasket position indicates seal failure.

Safe disassembly process

Relieve pressure and cool to ambient temperature.

Loosen the bolts in a cross order to avoid sudden popping of the flange surface.

Clean the old gasket residue (do not use sharp tools to scrape the flange).

• Storage and transportation specifications

Storage conditions

Environment: temperature 5-30℃, humidity ≤60%, away from acid and alkali corrosive gases.

Packaging: Original moisture-proof bag + hard box for storage, no stacking or bending.

Transportation requirements

Fixed in a shockproof box to avoid corrugation deformation caused by bumps.

Labels indicate "Do not press" and "Moisture-proof".