Find the right solenoid valve with these 7 questions

The choice of solenoid valve depends on many different parameters. See the 7 questions that can help you find the perfect solenoid valve.

A solenoid valve is not just a valve – it is much more than that. The choice of solenoid valve depends on many different parameters such as your application, the medium, the medium temperature, etc.

We have therefore asked our solenoid valve expert, Per Chrøis, how he helps customers find the right solution:

“It is wrong to think that a solenoid valve is just a solenoid valve. There are many different aspects to finding the perfect valve for your application. That is also why, at Hans Buch, we do not just deliver solenoid valves – we deliver to the customer’s application. It requires asking the right questions.”

Here are the 7 questions Per asks customers when he helps them find the right solenoid valve:

1) What application will the solenoid valve be used in?

“First and foremost, it is important to know whether the solenoid valve will be used for air, neutral gases, or liquids. Different applications set different requirements for the solenoid valve.”

2) What medium will the valve be used in?

“Your choice of solenoid valve primarily depends on the medium you need to open/close. Should it open/close for air/neutral gases or liquids? Is it air, neutral gas, water, diesel, or something completely different? The medium in which the solenoid valve will be used sets different requirements for, among other things, the material choice for your solenoid valve.”

“Different materials are more or less resistant to different air/gases and liquids. It all depends on the medium, the temperature in the medium, the surroundings, and the pressure conditions. The lifespan and functionality depend greatly on these parameters.”

“It is also important to remember that all media-contacted parts must be resistant to the medium.”

3) What is the temperature of the medium in which the valve will be used?

“It is important to consider the temperature when choosing your solenoid valve. The coil in the valve normally gets warm and must be able to withstand both its own generated temperature and the temperature in the medium. Here, you need to be aware of whether the medium is cooling or if it emits heat.”

“Additionally, the diaphragms and seals in the solenoid valve must also be able to handle the temperature.”

4) Is there a need for a normally closed or normally open valve?

“When you need to find your solenoid valve, it is important to consider whether you need a normally closed (NC) or normally open (NO) version. The most common to use is a normally closed (NC) valve. This means it is closed when the coil is inactive and open when the coil is activated. Normally open (NO) works the opposite way.”

5) How high or low is the pressure?

“Another important thing to consider is the pressure. The pressure range over a solenoid valve is crucial for the choice of solenoid valve. If there is, for example, a pressure difference across the valve (typically a minimum of 0.5 bar), you can use a so-called indirectly acting solenoid valve. This helps the pressure to open the solenoid valve, allowing you to use coils with relatively low wattage even for larger solenoid valves.”

“If there is no pressure difference across the solenoid valve when it needs to be activated, you typically need to use a coupled indirectly acting solenoid valve for larger sizes and directly acting solenoid valves for smaller sizes.”

6) What thread size do you need?

“To correctly size a solenoid valve, it requires knowing the flow in your application. It is an incredibly important part of sizing the size of your solenoid valve. Therefore, use the flow to size.”

“I encounter many who say: ‘we need a 1” solenoid valve because it needs to be mounted on a 1” pipe’, but it is not that simple. If the solenoid valve is not sized correctly, the risk of errors is high. With too high a flow, the seat in the solenoid valve can wear and corrode away. With too low a flow, you risk, with indirectly acting solenoid valves, that the diaphragm floats, so the solenoid valve does not know whether to open or close. Over time, the diaphragm will deform because there is not a large enough pressure drop across the solenoid valve.”

7) What voltage do you want?

“When choosing your solenoid valve, it is important to define whether you want AC voltage or DC voltage. For many solenoid valves, your choice of voltage makes a big difference. If you look at a solenoid valve’s datasheet, you will often see that the same solenoid valve has different pressures depending on whether it is with DC voltage or AC voltage.”