Rupture disc, safety valve, and relief valve have the functions. They protect process equipment and machine from overpressure.
They act as the protection devices – safety devices.
However, there is one significant difference between the rupture disc and the safety valve and relief valve.
What is the difference?
Rupture disc can be used only for one-time use. Once a pressure build-up is created in a piece of equipment or machine higher than its design pressure, it will burst.
Meanwhile, safety valve and relief valve will close again after releasing an over pressure.
To learn more about what rupture disc is, please read the following brief explanations.
Rupture disc can be used as over pressure protection as well as over vacuum protection.
It is designed to stand up to a certain pressure level before bursts.
It is free from function failure. The safety valve and relief valve can fail to function against overpressure. But, the rupture disc will not. Due to this benefit, many machine manufacturers – like chiller manufacturers – use it as an overpressure protection device.
Rupture disc design can be circle or square, one layer, or more than one layer.
The common materials used as rupture disc materials are metal, plastic and graphite.
It can be installed directly between two flanges or using a rupture disc holder. Or it can be welded directly to its holder.
If an overpressure happens, gas will flow out from the equipment or machine to the environment. In the case of a vacuum condition, air from the environment will flow into the equipment or machine through the damaged rupture disc.
Rupture disc diameter can meet with the diameter of flanges or pipes, with nominal size.
Burst pressure of set pressure is the design pressure of a ruptured disc at which it bursts.
Burst tolerance is the percentage of tolerance for the burst pressure. It means that if a rupture disc has a burst tolerance of 10% and set pressure 2 bar, so it will burst between 1.8 to 2.2 bar.
Some popular rupture disc manufacturers are Rembe and Donaldson.
There are several rupture disc types available in the market; sanitary rupture disc, forward acting, reverse acting, ultra low-pressure rupture disc, and double way.