Composite Reverse-Acting Rupture Disc
Product Model: ZD-RA04 (Lined Reverse-Acting)
Construction: Standard reverse-acting metal disc (e.g. 316L) with a PTFE or PFA liner on the process side.
Key Feature: Combines the mechanical benefits of reverse-acting design with the supreme chemical resistance of a fluoropolymer barrier.
Benefit: Protects the metal disc from corrosion and prevents product contamination or adhesion.
Primary Use: Highly corrosive gas/vapor services, polymer production, pharmaceutical API synthesis, and food processing where purity is critical.
Overview
When a process involves highly corrosive gases, sticky monomers, or requires absolute product purity, even a stainless steel reverse-acting disc may not be suitable. This composite design solves the problem by adding a seamless, inert PTFE or PFA liner to the process side of the disc. The liner isolates the structural metal disc from the aggressive media, while the reverse-acting mechanism underneath provides accurate, non-fragmenting burst performance. This offers the best of both worlds: the reliability of a metal safety device and the chemical compatibility of a fluoropolymer.
Features & Benefits
Complete Corrosion Isolation: The PTFE/PFA liner acts as an impervious barrier, allowing the disc to be used in services that would rapidly destroy unlined metals.
Non-Fragmenting & Non-Contaminating: Maintains the clean shearing action of a reverse-acting disc, and the liner ensures no metallic contact with the product.
Anti-Stick Properties: Prevents buildup of polymers or viscous materials on the disc surface, ensuring consistent performance and easier system cleanup.
Accurate Burst Pressure: The burst rating is determined by the underlying metal disc and is not significantly affected by the thin, flexible liner.
How It Works
System pressure is transmitted through the flexible liner to the metal reverse-acting disc. At the burst point, the metal disc buckles and is sheared as normal. The liner, being in intimate contact, tears concurrently with the metal, creating a fully lined opening. The sheared metal center and the liner are retained together.
Specifications (Descriptive)
Available in sizes from DN25 to DN150. The burst pressure range is based on the metal disc (e.g., 1-10 barg). The liner material is typically PTFE for general use (up to 150°C) or PFA for higher temperature resistance (up to 180°C). The liner is permanently bonded or mechanically locked to prevent delamination. The holder bore is often similarly lined to provide complete corrosion protection from flange to flange.
Q&A
Q: Can the liner plug the opening after bursting?
A: Proper design is critical. Our discs are engineered so the liner tears completely and is retained with the metal center, creating a clear, lined opening. The risk of plugging is very low.
Q: Is this disc suitable for liquid service?
A: The reverse-acting mechanism is not ideal for liquids. This lined version is still primarily for gas/vapor service. For lined liquid service, a forward-acting composite disc should be selected.
Q: How does temperature affect the liner?
A: The liner defines the upper temperature limit. Exceeding the continuous service temperature of the PTFE/PFA can cause softening, creep, or degradation, potentially affecting performance. Always select the liner material for the process temperature.
About ZD Safety
We specialize in hybrid solutions for complex challenges. Our composite reverse-acting discs break down the material barriers, enabling safe operation of advanced chemical and purity-sensitive processes with confidence.
