+91 97691 77244 +91 93264 07022
High-Temperature Solutions

Metal Bellow Mechanical Seal

Metal Bellow Mechanical Seal ⚡ Elastomer-Free Design

Technical Data

  • Faces: SSiC / TC / Carbon
  • Bellow Metallurgy: Hastelloy-C / AM350 / Inconel
  • Static Seals: Flexible Graphite / PTFE
  • Pressure Limit: Up to 25 bar
  • Temp. Limits: -75°C to 425°C
  • Shaft Speed: Up to 25 m/s

No Dynamic Elastomer & Extreme Temperature Performance

Metal bellow mechanical seals are engineered for severe-temperature environments and corrosive chemical services where standard elastomer-based seals would fail. By replacing the dynamic sliding O-ring or rubber bellow with an edge-welded metal bellows unit, this design completely eliminates shaft fretting, sleeve wear, and temperature-related static seal deterioration. The bellows itself functions as both the primary static seal and the spring loading element, maintaining uniform face pressure.

Micro Engineering designs edge-welded metal bellows seals using advanced metallurgy like Hastelloy-C, AM350, and SS316L. The flexible bellow structure features a self-cleaning profile, where centrifugal forces naturally throw suspended solids and abrasive contaminants away from the bellows plates, preventing clogging. Combined with flexible graphite (Grafoil) or PTFE secondary gaskets, these seals operate reliably in thermal transfer oils, refinery fractionating processes, and cryogenic services.

Ideal for refinery hot-oil pumps, heavy hydrocarbons, corrosive chemicals, heat transfer fluids, and steam-condensate systems.

Features & Benefits

Advanced welded metal bellows architecture built for harsh operating thresholds.

No Dynamic O-Ring

By removing the sliding dynamic elastomer on the shaft, these seals completely prevent sleeve fretting corrosion, shaft wear, and secondary seal hang-up.

Extreme Temp Tolerance

Utilizes edge-welded metallurgy and high-grade graphite secondary gaskets to operate safely in temperature extremes from -75°C up to 425°C.

Self-Cleaning Bellows

The smooth leaf-profile design of the welded plates sheds solids and fibers, preventing slurry build-up and keeping the seal highly resistant to clogging.

Uniform Face Sizing

Maintains consistent hydraulic balance and face load throughout the seal's lifespan, even under thermal expansion and shaft movement.

Design & Operational Boundaries

Comparing Metal Bellow Seals against Elastomer Bellow Seals (e.g. MG1).

Parameters Metal Bellow Seals Elastomer Bellow Seals (MG1)
Secondary Sealing Element Edge-welded metal bellows (no dynamic sliding elastomer). Molded rubber bellows (slides along the shaft).
Temperature Range -75°C to 425°C (Extreme High/Low). -20°C to 140°C (Elastomer-limited).
Shaft Sleeve Wear Zero (no sliding contact on shaft sleeve). Minimal, but dynamic friction can occur.
Chemical Compatibility Excellent (utilizes Hastelloy-C / Alloy 20 bellows). Moderate (dependent on Viton/NBR chemical limits).
Clogging & Slurry Tolerance Self-cleaning leaf profile sheds particles. Excellent, but bellows can stretch or wear in abrasives.
Initial Investment Premium (high manufacturing cost of welded plates). Very economical (simple molded design).

Typical Applications

High-temperature dynamic containment loops in demanding refining networks.

01

Petrochemical & Hot Oil

Sealing thermal heat transfer fluids, hot bitumen, fractionating bottoms, and high-temp hydrocarbons in refineries.

02

Corrosive Chemical Processing

Handling concentrated acids, strong oxidizers, and industrial solvents where Hastelloy-C bellows metallurgy is mandatory.

03

Cryogenic Fluid Services

Reliably sealing low-temperature media like liquid nitrogen, carbon dioxide, and liquefied petroleum gas (LPG).

04

Boiler Feed & Condensate

Managing high-pressure feed water loops, boiler circulations, and steam-condensate return lines where rubber parts degrade.

Why Choose Our Metal Bellow Seals?

Micro Engineering manufactures edge-welded metal bellows mechanical seals to withstand high heat, corrosive media, and severe shaft movements.

✓

Edge-Welded Plate Precision

Bellows plates are punched and edge-welded under inert gas chambers to prevent micro-fissures and guarantee long fatigue life.

✓

Grafoil Static Gaskets

We use certified flexible graphite (Grafoil) gaskets for the static packing, ensuring leak-free performance at maximum temperatures.

✓

Optically Lapped Faces

All sealing faces are polished to 1-2 light bands and helium-light tested to ensure instant sealing on pump startup.

✓

Balanced Without Shaft Step

Inherently balanced design allows operation under high pressures without needing a step on the pump shaft or sleeve.