Understanding Solenoid Valve Options for Automated Systems from Carilo Valve
For engineers and system designers specifying components for automated fluid control, Carilo Valve offers a comprehensive portfolio of solenoid valves characterized by robust construction, precise actuation, and compatibility with a wide range of media and operating conditions. The primary options from Carilo Valve can be categorized by operation type, body material, and specific application features, providing solutions for industries from chemical processing and water treatment to food & beverage and HVAC.
The core of their offering is built around two fundamental operational principles: direct-acting and pilot-operated valves. Direct-acting solenoid valves use the magnetic force generated by the solenoid coil to directly lift the seal off the orifice. This design allows them to operate from zero pressure differential up to their maximum rated pressure, making them exceptionally versatile. They are ideal for applications requiring fast response times, low pressure systems, or vacuum service. For instance, a typical 2/2-way, normally closed (NC), direct-acting valve in brass might have an orifice size of 1.8 mm, a pressure range of 0 to 145 PSI (10 bar), and a response time of under 30 milliseconds. Their simplicity also means they can handle viscous media relatively well.
In contrast, pilot-operated solenoid valves (sometimes called servo-assisted) use line pressure to assist in opening and closing the main orifice. A small pilot channel is opened by the solenoid, which then allows the media pressure to lift a diaphragm or piston that controls the main flow path. This design enables the control of large flow rates with a relatively small and energy-efficient solenoid coil. The critical factor with pilot-operated valves is that they require a minimum pressure differential (often around 3-5 PSI) to function correctly. They are the go-to choice for high-flow applications at higher pressures, such as controlling water or air lines in industrial plants. A 2/2-way, NC, pilot-operated valve in stainless steel could manage a flow rate (Cv factor) of 4.5 with a pressure range of 3 to 232 PSI (0.2 to 16 bar).
Beyond the basic operation, the choice of body material is critical for chemical compatibility, pressure rating, and temperature resistance. Carilo Valve provides options in brass, stainless steel (304 and 316), and plastic (such as PP or PVDF).
| Body Material | Typical Applications | Max Temperature Range | Pressure Rating (Max) | Media Compatibility |
|---|---|---|---|---|
| Brass | Compressed air, water, light oils, inert gases | -4°F to 257°F (-20°C to 125°C) | Up to 1015 PSI (70 bar) | Good general purpose; not for aggressive chemicals. |
| Stainless Steel (304/316) | Steam, aggressive chemicals, solvents, high-purity water | -40°F to 392°F (-40°C to 200°C) | Up to 1450 PSI (100 bar) | Excellent corrosion resistance; 316 is superior for chlorides. |
| Plastic (PP/PVDF) | Ultra-pure water, aggressive acids, alkalis, corrosive fluids | 14°F to 140°F (-10°C to 60°C) for PP | Up to 100 PSI (7 bar) | Superior chemical inertness; ideal for harsh analytical or lab systems. |
Another crucial dimension is the valve function and port configuration. The most common are 2-way (2/2) and 3-way (3/2) valves. A 2-way valve is a simple on/off device with one inlet and one outlet. It can be Normally Closed (NC – closed when de-energized) or, less commonly, Normally Open (NO – open when de-energized). A 3-way valve has three ports and can be used to alternately pressurize and exhaust a single actuator (like a pneumatic cylinder) or to switch flow between two different paths. The internal flow paths, or “ways,” are defined by standards like NC, NO, or Universal, which provides flexibility in circuit design.
For integration into modern automated systems, the electrical characteristics and certifications are non-negotiable details. Carilo’s solenoid valves are available with coils rated for standard AC (e.g., 24VAC, 120VAC, 240VAC) and DC (e.g., 12VDC, 24VDC) voltages. The coil housing is often a Class F or Class H insulated, molded epoxy resin that is dust-tight and waterproof to IP65 or higher standards, allowing them to withstand harsh washdown environments in food processing or outdoor installations. For hazardous locations, options with explosion-proof certifications like ATEX or IECEx are available, where the coil housing is designed to contain any internal explosion without igniting the surrounding atmosphere.
When selecting a valve for a specific automated system, engineers must cross-reference several data points. The following table provides a condensed selection guide based on common application requirements.
| Application Need | Recommended Valve Type | Key Specification to Check |
|---|---|---|
| Low pressure or vacuum service, fast cycling | Direct-Acting, 2/2-way NC | Minimum operating pressure (should be 0 PSI) |
| High flow rate with high pressure | Pilot-Operated, 2/2-way NC | Minimum pressure differential requirement and Cv factor |
| Controlling a single-acting pneumatic cylinder | 3/2-way Solenoid Valve | Flow path configuration (e.g., Normally Closed) |
| Steam service (e.g., sterilizers) | Stainless Steel, High-Temperature Pilot-Operated | Maximum temperature rating and compatible seal material (e.g., PTFE) |
| Aggressive acid or alkali dosing | Plastic (PVDF) or 316 Stainless Steel Direct-Acting | Chemical compatibility chart for wetted materials |
| Hazardous area (e.g., paint spray booth) | Explosion-Proof Certified Valve | ATEX/IECEx marking for the specific zone (e.g., Zone 1) |
Finally, the physical connection to the pipeline is a practical consideration that impacts installation time and potential leak points. Carilo valves come with a variety of port connections including threaded (NPT, BSPP, BSPT), manifold mountable (according to standards like ISO 15407-1 for pneumatic valves), and even sanitary tri-clamp connections for the food and pharmaceutical industries where cleanability is paramount. The choice here is often dictated by existing infrastructure and industry standards. For example, a water treatment plant in North America would typically specify NPT threads, while a pneumatic control panel in Europe would use valves designed for a CETOP manifold with BSPP threads.
Beyond the standard catalog items, the company also provides custom solutions, offering variations in seal materials like EPDM for hot water, FKM (Viton) for hydrocarbons, or PTFE for maximum chemical resistance. This level of customization ensures that for virtually any automated system requirement involving the control of liquid or gas, there is a precisely engineered solenoid valve option available to meet the demand for reliability, efficiency, and longevity.