Normally Closed Nylon Solenoid Valve — 2/2 Way Direct Acting, 0 to 1.0 MPa, up to 60 °C

Cematic's normally closed nylon solenoid valve is a 2/2-way direct-acting solenoid valve with a fiberglass-reinforced polyamide body — the lightest and most cost-effective material in the entire solenoid family, offering complete resistance to galvanic corrosion.

Its normally closed configuration keeps the fluid blocked while the coil is de-energized and releases it upon receiving an electrical signal, ensuring automatic safety shut-off in case of any electrical failure. Therefore, it is the correct choice for potable water systems, automated irrigation, non-aggressive fluid control, and applications where weight, cost, and corrosion resistance are priority selection factors.

Unlike brass or stainless steel solenoids, this normally closed nylon solenoid valve does not exhibit galvanic corrosion in humid, saline environments or in the presence of substances that attack metals — making it the right alternative for potable water systems, agricultural irrigation, and outdoor applications where the durability of metallic bodies is a maintenance factor.

Principle of Operation — Normally Closed Nylon Solenoid Valve from Zero Pressure

In the de-energized state (coil de-energized): the normally closed nylon solenoid valve remains in the closed position — the spring holds the plunger against the seat, blocking fluid flow. When the coil is energized, the electromagnetic field directly displaces the plunger and opens the flow, without the need for minimum differential pressure. When de-energized, the spring automatically returns the plunger to the closed position.

Its direct action operates from zero pressure (0 bar) — without a minimum differential pressure — so it functions correctly in systems that start without pressure, with variable pressure, or by gravity where the water column may be minimal. Consequently, it is more versatile than piloted solenoids in low-pressure conditions.

Why Nylon over Brass or Stainless Steel

The choice of body material defines the application scope of the solenoid. The normally closed nylon solenoid valve is the correct choice when:

• No galvanic corrosion: Nylon (fiberglass-reinforced polyamide) does not corrode in contact with water, humidity, salts, or fertilizers — unlike brass, which can suffer dezincification, and stainless steel, which can experience pitting with high chlorides. Therefore, it is the most durable option in irrigation systems using well water or fertigation.
• Lighter weight: The nylon body weighs significantly less than brass or stainless steel of the same diameter — an advantage in overhead installations, low-support piping, or portable systems.
• Lower cost: It is the most economical option in Cematic's catalog of normally closed solenoids for 1/8" and 1/4" diameters, making it ideal for installations with many control points where the total system cost is relevant.
• Potable water compatibility: Food-grade nylon does not leach metallic ions into the fluid — suitable for potable water systems and irrigation where water purity is a requirement.

Construction Materials

• Body: Nylon — fiberglass-reinforced polyamide. Mechanical strength, lightness, and total resistance to galvanic corrosion. Compatible with water, air, and non-aggressive fluids up to 60 °C.
• Plunger: Stainless steel — resistant to corrosion by the process fluid.
• Seat seal: NBR (Nitrile) — compatible with water, compressed air, and non-aggressive fluids up to 60 °C.
• Coil: Encapsulated, IP65 protection — suitable for humid, dusty, and outdoor environments.
• Connection: Female NPT thread — industrial standard in Mexico, available in 1/8" and 1/4".

Technical Specifications

Temperature Limitation — 60 °C Maximum

The maximum operating temperature for this normally closed nylon solenoid valve is 60 °C — lower than the 80 °C of brass solenoids with NBR and the 180 °C of versions with Viton. Therefore, it is the correct choice for cold water, room temperature water, and compressed air, but not for hot water, steam, or high-temperature process fluids. Consequently:

• ✅ Potable water and irrigation water at room temperature
• ✅ Compressed air in pneumatic systems
• ✅ Non-aggressive fluids up to 60 °C
• ❌ Hot water above 60 °C — use brass or SS304 solenoid
• ❌ Steam — use solenoid with Viton seal and metallic body

Fluid Compatibility

• ✅ Potable water — up to 1.0 MPa and 60 °C; no metallic ion leaching from the nylon body
• ✅ Irrigation and fertigation water — compatible with diluted fertilizer solutions; verify NBR compatibility
• ✅ Compressed air — up to 1.0 MPa; instrumentation and pneumatic control
• ✅ Demineralized water — no galvanic corrosion or ionic leaching from the body
• ⚠️ Temperature above 60 °C: the nylon body may deform — use brass or SS304 solenoid
• ⚠️ Fluids with suspended solids: install an upstream line filter
• ❌ Hydraulic oils, solvents, acids: nylon may not be compatible — verify with Cematic technical team or use brass / SS304 solenoid

Applications of the Normally Closed Nylon Solenoid Valve

Automated irrigation systems — the primary application
The normally closed nylon solenoid valve is the standard component in drip and sprinkler irrigation systems where low cost, no galvanic corrosion, and zero-pressure operation are required. Its nylon body resists continuous exposure to water, fertilizers, and field conditions without the oxidation or dezincification that can affect brass bodies with prolonged exposure. Furthermore, the NC configuration ensures irrigation cut-off in case of any electrical failure in the controller.

Potable water control in domestic and industrial installations
In potable water systems where the body in contact with the fluid should not leach metallic ions, this normally closed nylon solenoid valve is the correct choice. Food-grade nylon ensures that the water is not contaminated with copper, zinc, or chromium ions — unlike brass and stainless steel without food-grade certification. Consequently, it is the appropriate component for control points in potable water distribution systems in 1/8" and 1/4".

Low-cost and lightweight pneumatic systems
In pneumatic installations where budget and weight are relevant factors — portable equipment, distributed control systems with many actuation points, low-cost automation — this NC nylon solenoid offers the lowest investment per control point in the entire Cematic family. Likewise, its IP65 protection makes it suitable for industrial environments with humidity and dust without the need for additional protection.

Industrial automation of non-aggressive fluids
In production lines where the control fluid is water or air at temperatures below 60 °C, this direct normally closed nylon solenoid integrates automatic ON/OFF control from a PLC with immediate response and guaranteed safety shut-off. Therefore, it is the most economical alternative for low chemical requirement control points where brass or SS304 would represent unnecessary material over-specification.

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