Collection:3-Way Solenoid Valves

3-way solenoid valves direct flow between three ports. Unlike their 2-way counterparts, limited to simply opening or closing a flow path, 3-way solenoid valves offer an additional port to enable more complex control scenarios. These valves are crucial for complex routing applications, such as mixing, diverting, or alternating flow paths within a circuit. 3-way solenoid valves can be normally closed (NC), normally open (NO), or universal. Universal means the valve can be connected in either NC or NO to select one of two fluids or to divert flow from one port to another.

Suitable applications

• Fluid control systems: Automated control systems often use 3-way solenoid valves to start, stop, or direct fluid flow.
• Cylinder control: They are used to control the operation of pneumatic or hydraulic cylinders, where the valve directs air or hydraulic fluid flow into different sides of a cylinder to extend or retract it.
• HVAC systems: Integral in controlling refrigerant flow in heating, ventilation, and air conditioning systems.
• Vacuum applications: Some 3-way solenoid valves are designed to operate under vacuum conditions, controlling the flow in vacuum systems.
• Medical devices: Utilized for precise control of fluids and gasses in medical equipment such as dialysis machines and ventilators.
• Pilot valves: They can act as pilot valves that control the operation of larger or more complex valve systems.

3-way solenoid valve selection criteria

• Media type and materials: Choose a valve material that is chemically compatible with the media to avoid reactions and contamination. Opt for valves that prevent media contact with the solenoid (media-separated solenoid valves) for slightly contaminated media applications. Various valve housing materials are:
  • Brass: Cost-effective and durable for water, air, and neutral gasses.
  • Stainless Steel: Corrosion-resistant, ideal for aggressive fluids and hygienic processes.
  • PVC: Chemical-resistant and lightweight, suitable for corrosive substances.

The various seal materials for the valve are:

• • NBR (Nitrile Rubber): Ideal for general use, compatible with oils and fuels, and offers good abrasion resistance.
  • EPDM (Ethylene Propylene Diene Monomer): Best suited for hot water and steam applications, resistant to weathering and ozone.
  • PTFE (Polytetrafluoroethylene): Provides superior chemical resistance, suitable for aggressive media, and has a wide temperature range tolerance.

• Orifice size: Choose an orifice size that matches the required flow rate for your application. Larger orifices allow higher flow rates, while smaller ones restrict flow.
• Operating pressure: Select a valve to handle the system's pressure range. Ensure the valve operates effectively within your application's pressure range to prevent leaks or damage.
• Maximum temperature: The valve's materials must be suitable for the medium's operating temperature to avoid degradation of the seals and housing.
• Kv-value: This value represents the flow rate that passes through the valve. Select a valve with a Kv-value that meets your system's flow requirements for proper control.
• Voltage: Match the coil's voltage rating with your power supply. Incorrect voltage can lead to improper operation or damage to the valve.
• Circuit Function: Decide if you need a normally closed or open valve based on the default position required for your application.
• Connection type and size: Threaded connections are common for smaller pipes and offer a simple screw-in installation, while flanged connections are suitable for larger pipes and high-pressure applications, providing a robust and secure seal. The valve's thread size must be compatible with your system's connecting pipes to ensure a proper fit and avoid leaks. The valve's connection size should match the size of the pipes in your system to ensure a proper fit and seal.
• Duty cycle: Select a duty cycle that matches the frequency and duration of the valve's intended operation, ensuring it can handle the expected electrical load without overheating.
• Specialized design options: Custom design options like latching, energy efficiency, vacuum, high temperature, position feedback, and manual override are available for varying applications.
• Surface treatment: Consider the surface treatment based on the environment where the valve will operate; for corrosive or high-humidity environments, choose a valve with corrosion-resistant coatings such as nickel-plating or anodizing. A standard paint or powder coating may suffice for protection and cost-effectiveness for less aggressive conditions.
• Approvals: Confirm that the valve has the necessary certifications for your application, such as drinking water, ATEX, UL, and IEC.

Practical user considerations

• Solenoid valves are susceptible to dirt and can only be used with clean liquids and gasses.
• Solenoid valves use energy while activated, and the coil may get hot. A well-ventilated installation environment is recommended to dissipate the heat.
• Follow proper installation guidelines to ensure peak performance. This includes aligning the valve correctly with the flow direction and securing all connections.
• Conduct routine maintenance to prevent potential system failures. This may involve cleaning the valve, checking for wear and tear, and replacing worn components.
• Account for environmental factors affecting valve operation, particularly in outdoor or extreme conditions. This includes temperature extremes, moisture, and exposure to corrosive substances.