Why is a Rupture Disc Required? – Functions & Selections

Air Pressure is a very critical parameter that needs to be maintained every time in many devices and equipment, be it a tank or a vessel, or a pipeline. If pressure increases, then there are chances of the equipment getting burst.

So, there must be some means apart from a pressure transmitter to monitor this and stop the process quickly. A pressure transmitter will do this role, but it is best suitable for PLC and other controllers.

If a direct hardwiring interlock is required, then this transmitter will not be suitable as the wiring will become too complex then. For this, a safety instrument is used which detects the pressure and immediately cuts off the circuit. It is called a rupture disc.

Why is a Rupture Disc required?

Rupture discs are used in a wide variety of applications to provide pressure relief, regulate pressure, contain hazardous substances, and control fluid flow. The primary reason for using a rupture disc is to ensure the safety of the system and its users. By rupturing at a predetermined pressure, they can prevent a system from overpressurizing and causing damage or releasing hazardous materials into the environment.

What is a Rupture Disc?

A rupture disc is a safety device designed to protect a pressure vessel or system from overpressure or vacuum conditions. It is a thin metal plate with one or more holes in it, which is installed in a pressure vessel. When the pressure within the vessel exceeds the predetermined burst pressure of the disc, the disc will rupture, releasing the excess pressure and preventing a dangerous overpressure condition from occurring.

Rupture discs are used in a variety of applications, from industrial processes to medical devices, to protect both personnel and equipment from potential hazards.

The working principle of a rupture disc is based on the concept of a bursting diaphragm. The disc is designed with a predetermined burst pressure, which is usually higher than the normal operating pressure of the system. When the pressure within the system exceeds the preset burst pressure, the disc will rupture, releasing the excess pressure and preventing a dangerous overpressure condition from occurring.

Rupture discs are typically made from metals such as stainless steel, Hastelloy, Monel, and Inconel. They may also be made from other materials such as Teflon or other plastics. The material selected should be compatible with the system and its operating conditions.

Problems with Rupture Discs

Rupture discs have some potential problems that must be taken into consideration. These include:

• Wear and tear: Rupture discs are subject to wear and tear over time, which can cause them to fail prematurely.
• Corrosion: Corrosion can occur due to exposure to moisture and other corrosive substances. This can lead to a rupture disc becoming brittle and failing to operate properly.
• Pressure fluctuations: Pressure fluctuations can cause the disc to rupture prematurely, resulting in an unwanted release of pressure.
• Temperature fluctuations: Temperature fluctuations can also cause the disc to rupture prematurely, resulting in an unwanted release of pressure.
• Overpressure: If the pressure within the system exceeds the designed pressure of the disc, the disc may rupture prematurely. This can lead to an unwanted release of pressure.

Functions of Rupture Disc

Rupture discs are used in a wide variety of applications, including:

• Pressure relief: Rupture discs are used to provide pressure relief in systems that are subject to high internal pressures. By rupturing at a predetermined pressure, they can prevent a system from over pressurizing and causing damage.
• Pressure regulation: Rupture discs can also be used to regulate pressure in a system. By rupturing at a predetermined pressure, they can ensure that the pressure within the system remains within a safe range.
• Containment: Rupture discs can be used to contain hazardous substances within a system. By rupturing at a predetermined pressure, they can prevent a system from releasing hazardous materials into the environment.
• Flow control: Rupture discs can also be used to control the flow of fluids in a system. By rupturing at a predetermined pressure, they can help to regulate the flow of fluids in a system.

Selection of Rupture Disc

1. Determine the system’s operating pressure.
2. Determine the burst pressure required by the system.
3. Select a rupture disc with a burst pressure that is greater than or equal to the system’s operating pressure.
4. Determine the maximum flow rate of the system.
5. Select a rupture disc with a flow rate that is greater than or equal to the system’s maximum flow rate.
6. Consider any other system requirements such as corrosion resistance, temperature range, and chemical compatibility.
7. Select a rupture disc that meets all of the requirements.