Electromagnetic valves play a crucial role as automatic control components in the water treatment industry, widely used in various stages from raw water pretreatment to deep purification, reuse, and discharge. Its core advantages lie in fast response, precise control, remote/automatic operation, compact structure, and easy maintenance, which are very suitable for the requirements of modern water treatment systems for automation, intelligence, and reliability.
Backwash control system (filtration equipment)
Equipment types: multi-media filter, activated carbon filter, disc filter, sand filter, etc.
Function: After timed or pressure differential triggering, the solenoid valve opens to control the backwash water inlet/outlet and achieve filter material cleaning.
requirements
Normally closed (NC), powered on to open;
Resistant to particle erosion (recommended with Y-shaped filter pre installed);
Action lifespan ≥ 500000 times.
Reverse osmosis (RO) and ultrafiltration (UF) systems
Key uses:
Control of water inflow/concentration/production flow;
Low pressure flushing during startup (to prevent membrane fouling);
Quickly cut off water intake during emergency shutdown.
Technical Requirements:
High sealing performance (preventing leakage from affecting desalination rate);
Material compatible with pure water (316L stainless steel or food grade plastic);
Support PLC linkage (such as interlocking with high-pressure pumps).
Softening and desalination system (ion exchange)
Control content:
Control the injection of regeneration solution (saline);
Control the direction of water flow in each stage of forward washing, backwashing, and displacement.
Features:
Multi valve collaboration (often used in conjunction with multi way valves);
Resistant to corrosion by sodium chloride solution (EPDM or FKM seal).
Dosing and disinfection system
Application Scenario:
Sodium hypochlorite PAC、PAM、 Control the dosage of scale inhibitors and other chemicals;
Chlorine dioxide generator raw material (hydrochloric acid+sodium chlorate) pipeline switch.
Special requirements:
Corrosion resistant materials: PVDF, PTFE, Hastelloy alloy;
Diaphragm or piston structure to prevent drug crystallization from getting stuck;
Usually small caliber (DN6-DN25), high-precision control.
⚠️ Attention: Special anti-corrosion solenoid valves should be used for strong oxidizing or high concentration acid-base media. Ordinary brass valve bodies are prone to corrosion and failure.
Reclaimed water reuse and rainwater recovery system
Function:
Control the inflow and outflow of recycled water tanks;
Switching between tap water replenishment and reuse sources;
Rainy season overflow control.
Advantage: Achieve "intelligent quality water supply" and improve water resource utilization.
Sludge dewatering and discharge system
Application:
Control the intake of pneumatic diaphragm pump;
Control the opening and closing of the sludge discharge valve (in conjunction with timing or liquid level signals);
Filter cloth flushing water switch.
Environmental challenges: high humidity, dust content, and high vibration → IP65 or higher protection is required.
Emergency and safety interlock
Example:
Leak detection triggers the closure of the inlet valve;
Automatic drainage in case of power failure (normally open NO valve);
Switch water source priority in conjunction with the fire protection system.