ICON™ rupture disc

In short: The ICON™ is a tension-loaded rupture disc with cross scores and non-fragmenting opening, designed for vessels transporting liquids and gases: intermodal tank containers (ISO tank), railway tank cars and road tankers. Its typical use is upstream of the tank's pressure relief valve.

How it works

In a tension-loaded (forward-acting) disc the dome points toward the vent side and the process pressure pushes on the concave face, stretching the metal. When the burst pressure is reached, the disc opens. In the ICON™ the opening follows cross-shaped cuts, so the disc splits into sectors that fold outward and stay attached to the ring. This is what the term non-fragmenting refers to: no pieces of metal break off and travel with the flow.

That characteristic is what justifies its combined use with a pressure relief valve. The disc isolates the valve from the product while the tank is closed (preventing corrosion, buildup and seat leakage) and, when it bursts, leaves no particles that would keep the valve from reclosing or contaminate the cargo.

According to the manufacturer, the design is intended to withstand the vibrations and temperature changes inherent to transport, and it handles liquids, gases, and vapors both at rest and in transit.

When it makes sense (and when it does not)

• Suitable for ISO tanks, rail tank cars and tank trucks that carry a pressure relief valve and need to protect it from the product.
• Suitable when the load is corrosive, toxic or of high value and continuous losses through the valve are to be avoided.
• Suitable when quick replacement is needed in the yard or workshop, with the usual connections for the sector.
• Check whether the tank may be left under vacuum (for example, upon cooling or during discharge): a forward-acting disc usually needs a vacuum support.
• Check the operating pressure relative to the burst pressure: tension-loaded discs usually require more margin than reverse-acting ones.
• Confirm on your own which transport regulations apply to the tank; the manufacturer's datasheet only speaks of compliance in general terms.

Data to specify it

• Type of vessel and connection where it is installed.
• Burst pressure and design temperature.
• Product transported (phase and composition) and possible vacuum.
• Model and set pressure of the associated pressure relief valve.
• Disc material compatible with the load.

To go deeper: Rupture disc vs. pressure relief valve and Types of rupture discs.

Descriptive sheet for educational purposes. For availability and a quote for this model, consult P&V Control Devices.