Direct-Acting Normally Closed Bronze Solenoid Valve — 2/2 NC, 0 to 1.0 MPa

Cematic's direct-acting normally closed bronze solenoid valve is a 2/2-way direct-acting solenoid valve with a zinc-bronze body, zero-pressure operation, and the widest voltage range in the catalog — including 12V DC, which is the exclusive differentiator of this product compared to all other NC solenoids in the family. Therefore, it is the right choice for systems powered by 12V batteries, solar installations, vehicles, mobile machinery, and any application where the available power source is 12 volts direct current. Its normally closed configuration ensures automatic fluid shut-off in the event of any electrical failure — the standard safety state in most fluid control applications.

Unlike other NC solenoids in the catalog that only offer 24V, 110V, or 220V, this direct-acting normally closed bronze solenoid valve covers the four most used voltages in industry and field: 12 VDC, 24 VDC, 110 VAC, and 220 VAC — making it the most versatile option in the family for installations with different power sources.

Operating Principle — Direct-Acting NC Solenoid Valve from Zero Pressure

In the de-energized state (coil de-energized): the direct-acting normally closed bronze solenoid valve remains in the closed position — the spring holds the plunger on the seat, blocking the fluid flow. When the coil is energized, the electromagnetic field directly displaces the plunger, opening the flow regardless of the fluid pressure. When de-energized, the spring automatically returns the plunger to the closed position.

Its direct action operates from zero pressure (0 bar) — without minimum differential pressure — so it works correctly in systems that start without pressure, under gravity, or with variable pressure. Consequently, it is more versatile than pilot-operated solenoids in conditions of unstable pressure or cold starts.

The Key Differentiator: 12V DC

This is the only direct-acting NC solenoid in Cematic's catalog available in 12 volts direct current. Therefore, it is the correct choice in applications where no other NC solenoid in the family works:

• Solar systems and renewable energy: Fluid control in photovoltaic installations with 12V batteries — solar irrigation, water control in off-grid systems, tank filling.
• Vehicles and mobile machinery: Water, fuel, or air control in vehicles with 12V batteries — trucks, agricultural machinery, vehicle-mounted spraying equipment.
• Home appliances and consumer equipment: Water dispensers, industrial coffee makers, laboratory equipment, and machinery with 12VDC power sources.
• Control systems with 12V PLCs: Compact industrial installations where the available control voltage is 12VDC and a 24V source is not available.

Construction Materials

• Body: Zinc-bronze — superior corrosion resistance to conventional brass for water, compressed air, oils, and non-aggressive fluids. Zinc provides additional protection against galvanic corrosion in humid environments.
Plunger: Stainless steel — resistant to corrosion by the process fluid and with optimized mass for fast direct-acting response from zero pressure.
• Seat Seal: NBR (Nitrile) — compatible with water, compressed air, and mineral hydraulic oils within the specified temperature ranges.
• Coil: Encapsulated, IP65 protection — suitable for humid, dusty, and outdoor environments. Compatible with the four available voltages.
• Connection: Female NPT thread — industrial standard in Mexico for instrumentation and fluid control in small diameters.

Technical Specifications

Voltage Selection — Four Options Including 12V

• 12 VDC: Exclusive to this product in Cematic's NC family. For systems with 12V batteries — solar installations, vehicles, mobile machinery, home appliances, and laboratory equipment with 12-volt power sources.
• 24 VDC: Standard in industrial control cabinets with PLCs and DC power supplies. The most common option in new installations and modern automated systems.
• 110 VAC: For installations with 110 V circuits available in the field — the most widespread voltage in industry in Mexico.
• 220 VAC: For power panels with two-phase distribution or European standard.

Fluid Compatibility

• ✅ Potable water and process water — up to 1.0 MPa and 80 °C
• ✅ Compressed air — up to 1.0 MPa, -20 °C to 90 °C; pneumatics and instrumentation
• ✅ Mineral hydraulic oils — up to 1.0 MPa and 80 °C, compatible with NBR
• ✅ Natural gas and LPG — check local regulations and area classification before installation
• ⚠️ Fluids with suspended solids: install an upstream inline filter to protect the seal and orifice
• ⚠️ Temperature above 80 °C in water or oil: use a solenoid with Viton seal
• ❌ Concentrated acids, chlorinated solvents: use a solenoid with stainless steel body

Applications of the Direct-Acting Normally Closed Bronze Solenoid Valve

Solar and Off-Grid Systems — The Exclusive 12V Application
The direct-acting normally closed bronze solenoid valve with a 12V coil is the standard component in solar irrigation systems, automatic tank filling powered by photovoltaic panels, and off-grid systems where a 12V battery is the only available power source. Consequently, it is the only product in Cematic's catalog that addresses this need without requiring an additional voltage converter.

Vehicles and Mobile Machinery
In work vehicles, agricultural machinery, tanker trucks, and vehicle-mounted spraying equipment, the 12V electrical system of the battery is the universal standard. Therefore, this direct-acting NC bronze solenoid with a 12V coil controls the flow of water, fertilizers, or compressed air directly from the vehicle's battery, without the need for an additional power source or DC/DC converter.

Industrial Automation and Process Control
In industrial installations with 24V control cabinets or with 110V and 220V panels, this normally closed bronze solenoid valve integrates ON/OFF control of water, air, and oil from a PLC with automatic safety shut-off in the event of electrical failure. Likewise, the fluid-specific temperature ranges — up to 90 °C for air and up to 80 °C for water and oil — make it suitable for most industrial ambient temperature applications.

Home Appliances and Consumer Equipment with 12V DC
In water dispensers, purifiers, industrial coffee makers, and laboratory equipment with a 12V DC power source, this direct-acting NC bronze solenoid is the most economical and versatile fluid control component available at that voltage. In addition, its zero-pressure operation ensures correct functioning in low-pressure systems typical of these equipments.

For the complete range of solenoid valves, see solenoid valves collection →

Technical Data Sheet