Explosion vents, also known as rupture discs, are a critical safety device for pressurized machinery in many manufacturing facilities around the world. They help alleviate over-pressure and prevent catastrophic explosions that can damage equipment and severely injure workers.

It’s essential to understand their features and benefits, allowing you to make a more informed buying decision. Read on to learn more about the various types of explosion vents and how they can help improve safety in your manufacturing facility.

What is the purpose of an explosion vent? 

In the world of high-pressure manufacturing machinery, sometimes an over-pressurized situation can develop. If left unchecked, the pressure can cause the machine to explode, creating tremendous damage, and putting workers’ lives at risk.

An explosion vent is designed to tear open at pre-calibrated over-pressures in a deflagration (sudden burning of the vessel contents). This breakpoint is based upon careful calculations of the dimensions, strength, and contents of the vessel.

What components make up an explosion vent? 

They are scribed metal sheets (membranes) held to an opening in the protected vessel along with a matching frame. The membrane is kept in place by tension over a vent in the system. If the pressure building up behind it exceeds the established parameters, it will burst open. For a more controlled breakage scenario, some disc membranes will have scores cut into them.

What are the different types of explosion vents? 

There are four main types of explosion vents:

• Round
• Square
• Rectangular 
• Domed (able to withstand extreme vacuums so that they won’t implode)

They come in many standard or custom metal materials or composite metal/film sandwiches. They will tear open at prescribed over-pressures based on how they are scribed with precise “cuts.”

How are explosion doors used compared to explosion vents? 

Both explosion doors and vents open at predetermined over-pressures; however, a door is more robust. You can also reseal if activated by returning the vessel and door to their pre-event condition. On the other hand, an explosion vent only allows for a one-time pressure release event before it requires replacement.

What components make up an explosion door? 

They’re constructed out of a high-strength, lightweight honeycomb (moving) metallic door panel with calibrated pressure-relieving arms and magnetic mechanism. It’s secured to a robust door frame that’s mounted to the protected vessel. Door opening stops, access cages, and open door switching means are available to save equipment, personnel, or sense an upset condition. 

How easy is it to replace an explosion vent with an explosion door? 

If you’re considering replacing your explosion vents with doors, we would need to know the opening pressure of the explosion vent along with the existing bolt pattern to determine replacement availability.

What benefits are there to using an explosion door instead of an explosion vent? 

There are several benefits to using an explosion door instead of an explosion vent:

• The primary advantage of an explosion door is its reliability. You can re-use it many times over, whereas, with a vent, you will need to completely replace it if it explodes due to an over-pressurization event.
• Vents are susceptible to fatigue failures at the scribe lines in their membranes and require diligent maintenance to check for minute failures that can contaminate the process. Doors do not have this issue.  
• Door life is much greater than a vent membrane life.
• Doors allow production to view the vessel contents thru an open viewing area. 

Other advantages of explosion vents

The main downside to an explosion vent is that it’s not reusable. Once it performs its job, you will need to replace it. This can lead to production line shutdowns or long lead times if the part you need isn’t readily available. However, some of the other advantages that explosion vents do offer are:

• Some of them are designed to close up on their own, thereby preventing combustible fumes from escaping into the environment.
• They’re easy to replace and install.
• Due to their lightweight, they tend to be more sensitive.
• There are fewer moving parts in an explosion vent.

If you’re looking for more information about the advantages and disadvantages of opting for an explosion vent versus an explosion door, click the link below.

Rupture Discs vs. Explosion Doors