Flat Plate Bursting Disc
Product Model: ZD-BD10F (Flat Plate Disc)
Type: Non-reclosing pressure relief device, forward-acting, domed (tension-loaded) design.
Material: Standard materials include Aluminum, Stainless Steel (304, 316), Hastelloy®, and other metallic alloys. Available in standard or customized thicknesses.
Key Feature: Simple, reliable, and cost-effective pressure relief. The dome-shaped membrane fails in tensile rupture under overpressure, providing instantaneous full opening.
Overview
A often overlooked but critical hazard is vacuum collapse of tanks. During rapid pumping or cooling, a vacuum can form inside, potentially imploding the vessel. The tank vent flat rupture disc is a simple, economical device designed specifically as a vacuum breaker. It is a very thin membrane that ruptures at a slight vacuum (e.g., -5 mbar), allowing air to enter and equalize pressure before structural damage occurs. Some versions also provide minimal overpressure relief. It is a vital, last-line safety device for any tank not designed for full vacuum.
Features & Benefits
Prevents Catastrophic Collapse: Provides essential protection against tank implosion, a severe safety and financial risk.
Very Low Cracking Pressure: Extremely sensitive to small differential pressures, activating early in the danger zone.
Simple & Inexpensive: A low-cost insurance policy for valuable tank assets.
Easy to Install: Typically installs on a standard nozzle on the tank roof or upper shell.
How It Works
The disc is installed with one side exposed to atmosphere and the other to the tank headspace. Under normal conditions, it seals the opening. If the tank internal pressure drops sufficiently below atmospheric (creating a vacuum), the higher external atmospheric pressure pushes on the disc. When the differential exceeds the disc's very low negative rating, the disc bursts inward, allowing air to flow into the tank.
Specifications (Descriptive)
Sizes are typically DN50, DN80, DN100, DN150 to match standard tank vent openings. Set pressures are specified in mbar or inches of water column (e.g., -5 mbar, -10 mbar, or 1" H₂O). Materials include aluminum foil for non-corrosive atmospheres, 316 SS foil for corrosive vapors, or PTFE-coated materials. They are usually supplied with a weather hood to prevent rain ingress and a flame arrester if venting flammable vapors.
Q&A
Q: Does this replace a Pressure/Vacuum Relief Valve (PVRV)?
A: No. A PVRV is a reclosing device that breathes during normal operations. This is a non-reclosing, emergency device. They are often used together, with the rupture disc as a secondary, ultimate safety backup in case the PVRV fails or is insufficient for a major vacuum event.
Q: What happens after it bursts?
A: It is single-use. The tank is then vented to atmosphere until the disc is replaced. This signals that a significant vacuum event occurred, which should be investigated.
Q: How do I size it?
A: Sizing is based on the maximum anticipated air inflow rate needed to prevent vacuum during the worst-case emptying or cooling scenario, using standards like API 2000. The required flow area determines the disc diameter.
About ZD Safety
We protect your assets from all angles. Our tank vent discs address the silent hazard of vacuum, providing a simple, fail-safe mechanism to preserve the structural integrity of your storage infrastructure.
