Magpie Sealing Technology Sharing

Typical Sealing Applications: Common Forms in Industrial Valves

Following our previous discussion on ball valve seat sealing, this issue focuses on butterfly valves and other critical sealing forms in industrial valves.

Valve Seat Sealing
The triple-eccentric butterfly valve is widely used in modern industrial applications due to its excellent performance and unique design.

Radial Sealing: Sealing occurs along the disc diameter, providing low leakage and stable operation under high pressure, high temperature, and corrosive conditions.

Precision Requirements: The sealing surface and angle require specialized machining for optimal performance.

Nozzle Flange Sealing
Nozzle flange sealing is a critical step in valve assembly. Common methods include face sealing, line sealing, and quick sealing:

Face Sealing

Achieved at the gasket-flange contact surface.

Common gasket materials: flexible graphite, rubber, PTFE.

Widely used in valves, pipelines, and equipment connections for reliable leak prevention.

Line Sealing

Linear contact between the seal and flange.

Components: metal sealing rings, spring-energized seals.

Offers high reliability under high pressure and temperature, increasingly preferred in modern valve design.

Quick Sealing

Enables fast assembly and disassembly.

Uses threads, snap-fit mechanisms, or quick-connect structures.

Ideal for applications requiring frequent seal replacement.

Body-Bonnet Flange Sealing
Sealing at the body-bonnet flange ensures valve integrity under pressure. Common types include:

Standard Body-Bonnet Flange Sealing

Pre-tightened bolts compress sealing surfaces.

Critical for high-pressure applications where medium pressure enhances sealing stress.

Flat Face Flange Sealing

Uses an MF flange combination: female face (body) + male face (bonnet).

Compatible with spiral wound, corrugated metal, pure graphite, and reinforced graphite gaskets.

Offers excellent sealing in high-pressure environments.

Line Sealing for Body-Bonnet Flange

Employs C-ring or O-ring seals.

Advantages: improved tightness, reduced radial size, lighter and more compact design.

Self-Tightening Flange Sealing

Based on the Wood-type seal principle.

Modern designs use trapezoidal-section graphite rings.

Seal stress increases with medium pressure, making it highly effective for high-pressure applications.

Low-Emission Sealing Solutions from Magpie
Magpie Sealing provides reliable, low-leakage sealing solutions for industrial valves. For questions or consultations on sealing technology, follow us or reach out.

Stay tuned for the next issue, where we will explore different sealing gasket forms.