Which are the Frequently Asked Questions About Pressure Switches

Are you feeling overwhelmed by the variety of pressure switches on the market? Choosing the right one for your specific application can be hard when there are so many options available. That’s why we’ve taken the time to answer some of your most common questions and provide an in-depth guide to help you make an informed decision. With our straightforward guide, you can easily find the perfect pressure switch.

This article has taken five of the most frequently asked questions about pressure switches and provided detailed answers. With this in-depth look at pressure switches, you’ll be an expert in no time!

Pressure Switch

What is Differential?

Differential, or the range, is the difference in pressure between the cut-out (trip point) and the cut-in (reset point) of a pressure switch. The differential of a pressure switch can be adjustable or nonadjustable (fixed), depending on the make and model. For example, if the cut-out pressure is 50 PSI and the cut-in pressure is 30 PSI, then the differential is 20 PSI (50 PSI minus 30 PSI). This differential can be adjusted or left as is, depending on the switch and your specific needs.

An adjustable differential allows the switch to be adjusted in the field, allowing for a broader range of pressures to be set.

Differential and dead bands are the same. Some people may refer to differential as a “dead band” to refer to the difference between the actuation point and the re-actuation point in a pressure switch. For example, if a pressure switch is set to operate at 60 PSI on increasing pressure, it will actuate when the pressure rises to that point. The switch will then reactivate once the pressure drops to 40 PSI. This 20 PSI difference between the set point (60 PSI) and the reactivation point (40 PSI) is referred to as the “dead band” of the switch. Understanding this concept can help you understand how identical differential and dead bands are.

What is a Reverse Acting Pressure Switch?

A reverse-acting pressure switch is designed with contacts that open (N.O.) when the pressure falls and close when the pressure rises. This switch is commonly used to control ground ignition on gas-powered pumps and compressors when the maximum desired pressure has been reached. It can also be used as a low-pressure alarm to turn off motors in low-pressure situations. Reverse-acting switches can also act as remote switches, preventing the motor from running at low pressure and protecting it from damage.

What is Pressure Switch with a “Low-Pressure Cut-Off

Low-pressure cut-off switches are built with all the same features as a standard-type pressure switch but with an added low-pressure on-off feature to help extend the pump’s life.  When the pressure in the system drops to around 10 PSI below the set cut-in point, the switch will open and allow the pump to turn off, which helps prevent damage to the system due to low water conditions.  The manual lever must be manually turned to the start position to restore regular operation. The switch will resume normal operation if the pressure is fixed while the lever is held there.

Our low-pressure cut-offs are designed to protect your system from potential damage. With our range of 20-40, 30-50, and 40-60 cut-offs, you can ensure your system is safe from unexpected changes in pressure. Each cut-off is activated at an approximate pressure level ranging from 10 PSI to 30 PSI, giving you complete control over your system’s safety.

Start your pressure systems off right with pressure switches featuring low-pressure cut-out features. Hold the contacts closed manually to engage the switch by keeping the lever in the start position. This allows the pump to build the pressure in the tank up to within 10 PSI of the cut-in pressure setting of the switch. When you need to shut the pump down completely, move the lever to the off position.

In simple terms, what is an Auto-Off Pressure Switch?

An Auto-Off Pressure Switch is an ingenious device that allows you to turn it off manually and on your pump system for an extended period. It works by having a manual on/off lever that when in the “on” position, allows the switch to automatically turn on and off at the predetermined cut-in and cut-out pressure settings.  This eliminates the need for a regular manual switch, which only allows you to turn the pump on and off and does not include the ability to turn it off for an extended time.

When should Pressure Switches with Pulsation Plugs be used?

If you’re using a piston pump system, you should consider using a Form “P” pressure switch with the pulsation plug feature. The plug helps to reduce pressure spikes at the end of the piston stroke so that the pressure switch can operate more efficiently. Without the plug, sudden pressure spikes in the system can cause the contacts to open and shut off power to the pump, resulting in poor system performance. Installing a pressure switch with the pulsation plug will help ensure that your system operates properly and efficiently.


At BCST, we aim to provide the tools and information you need to safely and properly use our products. We strive to answer any relevant questions about pressure switches, so you can make the most educated decisions possible. If you have any additional questions, please don’t hesitate to contact us, and we will do our best to provide you with a thorough and helpful answer.

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