How to choose right option for a solenoid valve?

Diaphragm Solenoid Valves

Basic Knowledge of Solenoid Valves

Selection Methods

  1. Select the solenoid valve's nominal diameter (DN) and connection method based on pipeline parameters
    a. Determine the nominal diameter DN or mm size based on the on-site pipeline inner diameter or flow requirements.
    b. For connection methods, generally for DN10-DN50, threaded or flanged connections can be chosen as needed. For sizes <DN25, threaded connections are usually preferred, while for sizes >DN50, flanged connections are recommended. For large diameters, externally piloted bypass solenoid valves are used.
  2. Select the solenoid valve's material, sealing material, and temperature based on the medium type
    a. For corrosive liquids: Use stainless steel, engineering plastics, or PTFE (polytetrafluoroethylene, commonly known as Teflon) as the material, and choose fluororubber or PTFE as the sealing material.
    b. For heat-treated liquids: Use sanitary-grade materials and silicone rubber as the sealing material.
    c. For high-temperature liquids: Choose solenoid valves made of high-temperature-resistant chemical materials and sealing materials, preferably with a metal piston design. Avoid using for media exceeding 400°C.
    d. For fluid states: Depending on whether the medium is gaseous, liquid, or mixed, select the appropriate design, especially for sizes larger than DN25, as it relates to the pilot hole parameters.
    e. For fluid viscosity: For temperatures below 50°C, any type can be chosen. For higher viscosities, use high-viscosity solenoid valves.
    f. For fluid cleanliness: If the medium contains small impurities, a diaphragm structure can be used. Alternatively, install a filter before the solenoid valve. For larger pilot holes, engineering plastics and glass structures can be used if allowed.
  3. Select the control method based on operating duration or special requirements—normally closed, normally open, self-holding, emergency shut-off (manual reset), signal feedback, etc.
    a. For solenoid valves that need to remain open for long periods, choose normally open types.
    b. For frequent switching or short opening times, choose normally closed types.
    c. For safety-critical applications, such as furnace flame monitoring, gas leak alarms, and fire safety systems, choose emergency shut-off or normally closed solenoid valves.
  4. Power supply voltage selection: Prefer commonly used AC220V or DC24V for convenience.
  5. Select the solenoid valve's design type based on pressure rating
    a. Nominal pressure: This parameter is similar to other general valves and is determined based on 1.5 times the pipeline's nominal or operating pressure.
    b. Working pressure difference: This is the difference between the upstream and downstream pressures when the solenoid valve is closed or open. For zero, low, or vacuum pressure differences, use direct-acting or distributed direct-acting designs. For higher pressure differences, various designs can be used.
  6. Select the appropriate coil based on working requirements
    a. For high-frequency switching, use high-frequency coils that can withstand continuous switching.
    b. For long-duration operation, use high-temperature-resistant, long-life coils. For explosive environments, use explosion-proof coils.
    c. For high-temperature environments, use high-temperature-resistant coils. For high-pressure applications, use pressure-resistant coils.
    d. For vibrating environments, use anti-vibration coils, such as high-strength, shock-resistant coils for mining applications.
  7. Select auxiliary functions based on environmental requirements: explosion-proof, manual, waterproof, water spray, timer
    a. For flammable or explosive environments, use explosion-proof solenoid valves with appropriate ratings (dIIBT4, dIICT6, dIICT6, ExmII/IT4).
    b. For manual operation, choose solenoid valves with manual override.
    c. For outdoor or dusty environments, use waterproof and dustproof models (IP54 or higher). For fountains or underwater pipelines, use submersible solenoid valves (IP68 or higher).
    d. For timed operations, use solenoid valves with timers.

Installation Guidelines

installation valve

  1. Before installation, carefully check the nameplate to ensure the parameters meet the usage requirements. Verify the reliability of the cable grounding and familiarize yourself with the installation points.
  2. Ensure the medium is clean. If the medium contains rust or impurities, install a filter in the pipeline.
  3. Install the solenoid valve vertically, with the valve head aligned with the pipeline flow direction.
  4. The solenoid valve should operate within a voltage range of 10% to 15% of the rated voltage.
  5. If the pipeline lacks rigidity, secure the pipeline before the valve to prevent vibration during operation.
  6. For maintenance or continuous production, use a bypass isolation installation method (as shown in the diagram).

Common Fault Diagnosis and Handling

  1. Solenoid valve does not operate when powered
    a. Coil winding short circuit—replace the coil.
    b. Low power supply voltage—adjust the voltage within the -10% to +10% range.
    c. Medium pressure in the pipeline does not meet the operating pressure range—adjust the pressure or replace the valve.
  2. Solenoid valve does not operate when power is disconnected
    The valve core is stuck and cannot reset—disassemble, clean, and reassemble by a professional.
  3. Leakage issues
    a. Sealing components are damaged or aged—replace the seals.
    b. Debris inside the valve body—clean the debris.