Composite Type C – Vacuum Bursting Disc

The Composite Type C – Vacuum bursting disc is designed for low to medium vacuum and underpressure protection, providing highly accurate and repeatable opening characteristics. Using state-of-the-art laser machining, predetermined breaking points are cut into foils of stainless steel, nickel, Inconel, Hastelloy* or tantalum, enabling precise burst values as low as 20 mbar at 20 °C.

When the allowable differential pressure is exceeded, the foil opens in a segmental, hinge-like, fragment-free pattern. This controlled opening behaviour makes the disc ideal for vacuum protection on vessels, lines and equipment, and for installation upstream of sensitive components such as safety valves. A PTFE or PFA sealing diaphragm is fitted between the slotted metal foils, ensuring tightness and chemical resistance at operating temperatures up to 200 °C.

Technical Capabilities

• Optimised for vacuum / underpressure protection at low to medium pressures
• Minimum burst pressures from 20 mbar (at 20 °C)
• Operating temperature capability up to 200 °C
• Standard nominal widths from DN15 to DN900
• Material options: stainless steel, nickel, Inconel, Hastelloy*, tantalum
• Fragment-free, hinge-type opening to protect downstream equipment

Design Variants & Mounting

Composite bursting discs are available as:

• Overpressure bursting discs
• Underpressure / vacuum bursting discs (this type)
• Bi-directional bursting discs for combined overpressure and vacuum protection

All variants can be mounted:

• Directly between standard flanges in accordance with EN 1092
• Directly between flanges to ASME B16.5
• In dedicated holders
• In clamp couplings

Burst Detection Options

• Membrane signal transmitter for discs mounted directly between flanges without a holder
• Signal transmitter with inductive proximity switch for discs in holders or clamp couplings

Benefits

• Individually specified for material, burst pressure and dimensions
• Extremely low burst pressures achievable with large nominal diameters
• Fragment-free opening for maximum process and equipment safety
• Available with integrated burst detection for monitoring and control
• Support-free mounting possible depending on configuration and duty

The Composite Type C – Vacuum disc combines precise vacuum protection, robust materials and flexible mounting options—delivering a high-integrity, configurable solution for critical process applications.

Technical Specifications: