Solenoid valves improve water treatment equipment efficiency by providing fast and repeatable control of air, water, chemicals, drainage, flushing, and pneumatic actuators. However, the valve itself is only part of the solution. Correct selection must consider the medium, pressure, flow, temperature, switching frequency, materials, and control requirements.
As water reuse, wastewater treatment, and environmental protection become increasingly important, treatment equipment is also becoming more automated. The United Nations reported in its 2024 World Water Development Report that 2.2 billion people lacked safely managed drinking water and 3.5 billion lacked safely managed sanitation.
Modern treatment equipment increasingly combines sensors, PLCs, pumps, automated valves, pneumatic actuators, and solenoid valves to create repeatable process sequences.
A typical pneumatic control chain is:
PLC → Solenoid Valve → Compressed Air → Pneumatic Actuator → Process Valve → Water Flow
This makes the solenoid valve a small but important component in automated water treatment systems.
Water treatment is fundamentally a process-control application.
Filtration, backwashing, reverse osmosis, chemical dosing, drainage, and disinfection all require different flow paths to open and close at specific times.
For example, an automatic filtration system may operate through this sequence:
Normal filtration → Condition detected → Backwash → Drainage → Rinse → Return to service
When pneumatic actuators operate the process valves, solenoid valves provide the control signals that determine when those actuators move.
A reliable control system helps equipment manufacturers achieve:
Repeatable valve switching
Consistent process sequencing
Reduced manual intervention
Easier troubleshooting
More predictable equipment operation
The U.S. EPA also identifies automated valves, pumps, sensors, and real-time control as important elements in modern wastewater and smart sewer systems.
Solenoid valves can support many functions in water treatment and environmental equipment.
Filtration
They can control pneumatic actuators used to switch filtration and isolation valves.
Backwashing
During automatic backwash cycles, solenoid valves can help control the pneumatic sequence required to change valve positions.
Reverse Osmosis
Automated valves may be used for flushing, drainage, isolation, and other process sequences. Valve pressure and material compatibility must always be checked against the actual application.
Chemical Dosing
Solenoid or fluid-control valves can provide ON/OFF control for compatible chemicals, cleaning fluids, and disinfection processes.
Wastewater Treatment
Applications may include drainage, flushing, pneumatic valve actuation, and automated process switching.
Environmental Equipment
Pneumatic control can also be used in scrubbers, filtration equipment, dust collection systems, and other industrial environmental control equipment.
One of the most common mistakes in valve selection is treating every water application as the same.
Engineers should first ask:
What exactly is flowing through the valve?
Clean water, wastewater, RO water, chemical solutions, and cleaning fluids can have very different requirements.
For wastewater, engineers may need to consider:
For chemical applications, material compatibility becomes critical.
The valve body and seals must be compatible with the actual medium, concentration, pressure, and temperature.
This is why a valve suitable for clean water should not automatically be used for wastewater or aggressive chemicals.
From an engineering perspective, valve selection should follow the process rather than the catalog.
1. Identify the Medium
Determine whether the valve controls:
2. Check Pressure
Confirm minimum, maximum, and differential pressure.
3. Calculate Flow
Consider required flow rate, pressure drop, port size, and flow coefficient where applicable.
Pipe size alone should not determine valve size.
4. Check Temperature
Consider both medium temperature and ambient temperature because temperature affects seals, materials, and coil performance.
5. Select Materials
Check body and seal compatibility with the actual fluid.
6. Check Electrical Requirements
Common options include 12 VDC, 24 VDC, 24 VAC, 110 VAC, and 220/230 VAC, depending on the control system.
7. Consider Duty Cycle
A valve operating every few seconds has very different requirements from one operating several times per day.
8. Consider the Environment
Humidity, dust, corrosion, vibration, and water exposure can all affect long term reliability.
For equipment manufacturers, selecting a solenoid valve is only one part of designing an automated machine.
The larger requirement is reliable communication between the controller, pneumatic system, actuator, and process valve.
MAXAIR provides pneumatic and fluid-control components that can be integrated into automated equipment.
For pneumatic applications, the control architecture can be:
PLC
↓
MAXAIR Solenoid Valve
↓
Compressed Air
↓
Pneumatic Actuator
↓
Process Valve
This approach is particularly useful when the solenoid valve controls an actuator rather than directly handling the process water.
MAXAIR MSY Series
The MSY Series valve island is designed for modular pneumatic control applications. Its modular configuration allows multiple pneumatic valves to be integrated into one control platform, making it suitable for equipment where several actuators need to be controlled from a centralized pneumatic system.
The series also offers internal or external pilot configurations and IP65 protection, depending on the specific configuration.
MAXAIR VNP Series
For applications involving direct fluid control, MAXAIR also offers the VNP Series, designed for applications involving air, water, and low-viscosity liquids.
Its specifications should be matched to the actual pressure, temperature, medium, and flow requirements of the application.
This distinction is important:
Pneumatic Control
Electrical Signal → Solenoid Valve → Compressed Air → Actuator
is different from:
Direct Fluid Control
Control Signal → Fluid-Control Valve → Process Fluid
The correct MAXAIR product therefore depends on the actual system architecture.
For equipment manufacturers, this application-first approach can simplify component selection while creating a more reliable automation system.
Water treatment automation is not simply about opening and closing valves.
It is about coordinating sensors, controllers, solenoid valves, pneumatic actuators, process valves, pumps, and treatment processes into one reliable system.
A properly selected solenoid valve can support:
But the most important engineering principle remains simple:
Do not select the solenoid valve first. Understand the process first.
For water treatment and environmental equipment manufacturers, the right combination of valve technology, materials, pressure, flow, electrical specification, and pneumatic control can make automation more predictable and easier to maintain.
That is where a component supplier such as MAXAIR can provide value—not simply by supplying a valve, but by supporting the pneumatic and fluid control architecture behind the equipment.
