Low-Pressure,Reverse-Acting Rupture Disc
Product Model: ZD-RA05 (Low-Pressure Reverse-Acting)
Material: Thin-gauge stainless steel (316L) or nickel alloys.
Pressure Range: Very low pressure, typically 0.1 barg to 2.0 barg.
Key Feature: Engineered to operate reliably at very low differential pressures where precision and sensitivity are paramount.
Design: Lightweight dome and low-friction supports to minimize inertia and activation energy.
Primary Use: Protecting low-pressure vessels, atmospheric storage tanks, environmental test chambers, ventilation systems, and research apparatus.
Overview
Protecting equipment that operates at or near atmospheric pressure presents a unique challenge: the safety device must be sensitive enough to activate at a very low overpressure, yet robust enough to handle normal environmental fluctuations. This low-pressure reverse-acting disc is meticulously calibrated for this duty. Its ultra-thin, precisely formed dome requires minimal force to initiate the buckling reversal, ensuring a fast and accurate response to small pressure excursions. It is the reliable guardian for equipment where even a slight overpressure could cause damage or compromise safety.
Features & Benefits
High Sensitivity: Capable of being set to burst at pressures as low as 100 mbar (0.1 barg) with good accuracy.
Fast Response: Low mass and optimized design ensure rapid buckling action once the set pressure is reached.
Non-Fragmenting: Maintains the clean operation of the reverse-acting principle, important for low-pressure systems often connected to filters or sensitive instruments.
Resists False Activation: Designed to withstand normal pressure ripples and wind loading on vents without premature buckling.
How It Works
The principle remains the same, but the dome is much thinner and more delicately balanced. The knife blades or shear mechanism are also precision-matched to this lightweight disc. At the very low set pressure, the compressive load causes elastic instability, the dome snaps, and is sheared cleanly.
Specifications (Descriptive)
Sizes are often in the small to medium range, from DN50 to DN200, common for tank vents and ducting. Burst pressures are specified in small increments (e.g., 0.2, 0.5, 0.7, 1.0 barg). Tight manufacturing tolerances are essential to achieve repeatable low-pressure performance. The disc may incorporate special anti-stick coatings or treatments to prevent adhesion from dust or moisture that could affect the sensitive set pressure. Holders are designed to provide stable, even support.
Q&A
Q: What can cause a false burst in a low-pressure disc?
A: Mechanical impact/vibration, water hammer, condensation freezing on the disc, or a buildup of dust/debris adding weight or causing adhesion. Proper installation location, orientation, and sometimes protective screens are important.
Q: Can this be used for vacuum relief as well?
A: This specific design is for overpressure. However, the reverse-acting technology is excellent for vacuum service. We offer separate or combination (P/V) discs specifically for vacuum relief applications.
Q: How is the burst pressure tested at such low levels?
A: Specialized test equipment using precise pressure controllers and low-volume chambers is required to accurately measure and validate the burst pressure without the inertia of the test system affecting the result.
About ZD Safety
Precision at any pressure. Our low-pressure reverse-acting discs demonstrate that reliable safety isn't just about handling high forces—it's about guaranteed response at the exact required point, even when that point is measured in just millibars.
