At S3 Cases, our goal is to build protective cases for valuable equipment that will not only last a lifetime but also last through anything life throws at them. Our cases are designed with the highest quality materials and components and they also offer a number of added features to ensure that your equipment is protected regardless of the exterior conditions. One of our most beneficial features is the pressure release valve used to help the case adjust to changes in outside pressure. Read on to learn more about what a pressure release knob does and how it can benefit you.
Why Is a Pressure Release Knob Needed?
Our line of cases is designed to be airtight in order to protect your items from moisture, dust, or other elements. However, when outside pressure changes and air can’t get in or out, it causes a pressure differential, putting the case at risk of either deforming or becoming vacuum-sealed. The pressure release knob is there to help equalize the interior pressure of the case and keep it in line with the air pressure outside of it.
Protective cases can be affected by either a positive or negative pressure differential depending on the changes.
- Positive Pressure Differential: This occurs when an enclosed area, such as the interior of a protective case, has a higher pressure than the pressure levels surrounding it. It can happen, for example, if the case were to travel from sea level to a higher elevation. It can also happen if a case is first sealed in the cooler air of night and is then left out in the sun the next day. As air pressure increases within the case, whether from elevation or temperature, it causes the case to pressurize and could cause it to deform or bulge putting the effectiveness of the seal at risk.
- Negative Pressure Differential: In contrast, this occurs when the pressure within the case is lower than the pressure surrounding it. It would happen if the case were to travel from high elevation down to sea level. This could cause a partial vacuum seal making it hard to open or even causing the sides to indent.
You can find out more about what happens during changes in pressure in this article.
How Does a Pressure Release Valve Work?

In order to counteract the effects of positive or negative pressure differentials, we designed our S3 line of protective cases with a pressure release valve that responds to changes in pressure, keeping your valuable equipment protected. The valve is designed with springs that open and close, allowing air to flow accordingly in response to the changes in pressure.
The valve will open to let air out of the case when the pressure within it is higher than the pressure outside of it. Alternatively, it will let air in to the case when the pressure inside is lower than the pressure outside of it. Click here to learn more about pressure release valves and they work.
Benefits of a Pressure Release Valve
The primary benefit of a pressure release valve on a protective case is to ensure that the valuable items and equipment within it remain protected regardless of the conditions outside of it. At S3 Cases, we build our cases to withstand the harshest elements including weather, extreme temperatures, and even impact; with our pressure release knob, we extend that level of protection to changes in pressure.
A pressure release knob also works as an alternative solution for pressure equalization. Making a case even stronger would help to ensure equalization within the case. However, in order to do so, we would have to add both size and weight to it, taking away the lightweight properties of our cases that are so highly demanded. The pressure release knob provides an effective alternative by allowing just enough air to flow in or out without making the case bigger or heavier.
When the valve opens, it opens slightly and just long enough to let air flow in without allowing moisture to enter. If the valve were to remain open for too long, moisture would make its way into the case and affect the condition of your items. The superior design of our valves and cases will prevent moisture from entering the case, even when the valve has opened.
To learn more about the effectiveness of a pressure release knob or for any other questions concerning our line of protective cases, contact us at S3 Cases today.