In short: The ENVIRO-SEAL is a flat-seat composite rupture disc that, rather than protecting against high overpressure, serves as a seal: it isolates the vent side, contains emissions, and protects against corrosion in low-pressure storage vessels.
How it works
A composite disc separates two functions that in a simple metal disc fall on the same part. The metal top section, slotted or perforated, defines the mechanical behavior and the opening; the non-metallic seal provides tightness and chemical resistance. When the pressure exceeds the burst value, the seal yields and the metal section opens, allowing flow to pass.
In the ENVIRO-SEAL the seal can be placed in three positions depending on the application: on the process side, on both sides (process and vent), or sandwiched between two metal sections. Placing it on the process side protects the metal from the fluid; placing it on the vent side as well protects against the atmosphere or against whatever arrives through the discharge header.
Because it is flat-seat, the disc does not need a special seat geometry: the manufacturer states it is sized to be installed between standard companion flanges with ASME, DIN, or JIS bore, without adapters.
When it makes sense (and when it does not)
- Suitable for low-pressure tanks where the aim is to prevent vapors from escaping continuously to atmosphere (fugitive emissions).
- Suitable for isolating the vent: preventing moisture, air, or header contaminants from entering the vessel.
- Suitable as an anti-corrosion barrier ahead of a downstream device, for example a pressure relief valve or a flame arrester.
- Not suitable if the process temperature or the fluid is incompatible with the seal material; in that case, an all-metal disc is more appropriate.
- Review whether high burst accuracy or severe cyclic service is required; flat-seat discs usually work with more conservative operating margins, so the operating ratio should be confirmed with the manufacturer.
Data to specify it
- Line size and flange standard (ASME, DIN or JIS).
- Desired burst pressure and service temperature.
- Process fluid and environment on the vent side.
- Seal position: process side, both sides or between metal sections.
- Main function: environmental seal, anti-corrosion barrier or isolation.
| Type | Composite, flat seat |
|---|---|
| Construction | Metal top section with non-metallic seal |
| Seal position | Process side, both sides or between two metal sections |
| Mounting | Between standard ASME, DIN or JIS flanges |
| Typical use | Low-pressure storage vessels |
Learn more: Types of rupture discs and Installation and disc holders.
Descriptive sheet for educational purposes. For availability and a quote for this model, consult P&V Control Devices.