AirTAC NAMUR Interface Solenoid Valve: The Perfect Integration of Industrial Standard and Reliability

Introduction

In process industries (such as chemical, oil & gas, and power), the control of valve actuators must adhere to unified international standards to ensure compatibility across different brands—the NAMUR (National Association of Measurement and Control) interface standard is the "universal language" in this field.

The AirTAC 4M Series NAMUR Interface Solenoid Valve strictly complies with the NAMUR VDI/VDE 3845 standard. Designed specifically for valve control in process industries, it achieves "plug-and-play" compatibility and industrial-grade reliability, making it the preferred solution for process control scenarios. This article details the standard features, technical advantages, and application value of the 4M Series.

I. NAMUR Interface Standard: Why It's the "Universal Protocol" for Process Industries

The NAMUR interface is an installation and connection standard developed for valve actuators (such as pneumatic diaphragm actuators and cylinder actuators). Its core requirements include:

1. Mechanical Installation Standard: Unified solenoid valve mounting hole pitch and dimensions, allowing direct installation onto NAMUR standard actuator brackets without the need for additional adapters.

2. Pneumatic Port Standard: Standardized location and size of the air inlet (P), outlets (A/B), and exhaust ports (R/S), ensuring seamless connection with the actuator's air circuit.

3. Electrical Port Standard: Solenoid coil terminals follow a standard layout, supporting quick plug-in connections and compatibility with explosion-proof junction boxes used in process industries.

Solenoid valves adhering to this standard are compatible with actuators from international brands like Siemens, ABB, and Fisher, solving the adaptation problems between different branded equipment and reducing system integration costs.

II. Core Technical Advantages of the 4M Series NAMUR Solenoid Valve

1. Standard Compliance: Plug-and-Play Lowers Integration Difficulty

The 4M Series (e.g., 4M210-08, 4M310-10) is designed in strict accordance with the NAMUR VDI/VDE 3845 standard. It features a mounting hole pitch of 52mm (standard dimension) and pneumatic ports of G1/4" (P/A/B ports) and G1/8" (R/S ports). It can be directly mounted onto NAMUR actuators, reducing installation time from 1 hour to 10 minutes. The coils support DIN 43650 standard plugs for quick connection to explosion-proof junction boxes, meeting the explosion protection requirements of process industries (some models support Ex d IIB T4 explosion-proof rating).

2. Wide Pressure Range: Adapting to Diverse Actuator Needs

With an operating pressure range of 0.2 ~ 1.0 MPa and a maximum proof pressure of 1.5 MPa, the 4M Series can drive both single-acting and double-acting NAMUR actuators.

• Single-acting actuators (spring return) switch valves by alternating air supply through A/B ports.

• Double-acting actuators maintain position through continuous air supply via A/B ports.

  The 4M Series accurately adapts to both, with a starting pressure as low as 0.2 MPa, ensuring smooth actuator operation.

3. Resilience to Harsh Environments: Ensuring Reliability in Process Industries

• Protection Rating: Valve body protection is IP65, and coil protection is IP67 (with waterproof plug), offering resistance against dust, rain, and corrosive gases (such as light acid/alkaline mist).

• Operating Temperature: -40°C ~ 80°C (low-temperature models are available), suitable for outdoor equipment in northern winters or environments near high-temperature reactors.

• Vibration and Shock Resistance: Complies with IEC 60068-2-6 (Vibration) and IEC 60068-2-27 (Shock) standards, ensuring stable operation in high-vibration environments near pumps and compressors.

4. Low Power Consumption & Long Lifespan: Reducing Operational Costs

Coil power consumption is as low as 3.0W (DC24V models), and AC models consume 4.5VA. Low long-term heat generation (temperature rise $\le 80^{\circ}\text{C}$) reduces energy consumption. The spool features stainless steel with Fluorine rubber seals, providing a mechanical lifespan of $\ge 5$ million cycles. In scenarios requiring 1,000 operations per day, the service life can exceed 10 years, significantly reducing replacement frequency.

III. Typical Applications of the 4M Series: The "Control Link" in Process Industries

1. Chemical Industry: Reactor and Pipeline Valve Control

Feeding, discharging, and venting valves on chemical reactors require remote control via NAMUR actuators. The 4M Series solenoid valve acts as the "command execution unit," receiving PLC signals to drive the actuator, ensuring accurate valve switching (response time $\le 0.05$ seconds) to prevent material leakage or runaway reactions. Its anti-corrosion and wide-temperature design adapt to the harsh environment of chemical plants.

2. Oil & Gas Industry: Wellhead and Pipeline Control

Choke valves and safety valves at oil wellheads, and shut-off valves in natural gas pipelines, all use NAMUR standard actuators. The 4M Series solenoid valve can be directly installed, adapting to high-pressure (1.0 MPa) and outdoor low-temperature ($\text{-40}^{\circ}\text{C}$) environments, ensuring reliable operation even under extreme conditions, thus guaranteeing the safety of oil and gas transport.

3. Power Industry: Boiler and Environmental Equipment Control

Feedwater valves and steam valves in thermal power boilers, and slurry valves and flue gas valves in environmental desulfurization and denitrification equipment, are controlled by the 4M Series solenoid valve driving the actuator to achieve precise regulation of flow and pressure. The anti-vibration design withstands the strong vibrations during boiler operation, and its long lifespan reduces downtime for maintenance.

4. Water Treatment Industry: Wastewater Process Control

Aeration valves, sludge discharge valves, and dosing valves in wastewater treatment plants use NAMUR actuators for automated control. The 4M Series solenoid valve is suitable for humid and dusty workshop environments, and its oil-free lubrication design prevents oil contamination of the water body, meeting environmental requirements.

IV. Selection and Installation Notes

1. Actuator Type: Select "single-solenoid" NAMUR valves for single-acting actuators, and "double-solenoid" models for double-acting actuators.

2. Explosion-Proof Requirement: In explosion-hazard environments, choose models with Ex explosion-proof certification and ensure the wiring method complies with explosion-proof regulations.

3. Air Quality: A 5 $\mu$m high-precision filter must be installed at the air inlet to prevent impurities from blocking the spool (process industry air sources are prone to oil contamination and dust).

4. Low-Temperature Scenarios: For ambient temperatures below $\text{-20}^{\circ}\text{C}$, select the low-temperature coil model (resistant to $\text{-40}^{\circ}\text{C}$) to prevent coil freezing damage.

Summary

The AirTAC 4M Series NAMUR interface solenoid valve, with its core advantages of "standard compliance, resilience to harsh environments, and long lifespan," perfectly solves the adaptation challenge between different branded equipment in the process industry, becoming the "reliable link" between the valve actuator and the control system. From chemical and oil & gas to power and water treatment, the 4M Series ensures the precision and safety of process control with industrial-grade reliability.

If you are selecting a NAMUR solenoid valve for a process industry project, please contact the AirTAC technical team for a compatibility verification report. You can download the "4M Series NAMUR Solenoid Valve Product Manual" on the AirTAC official website to learn more about explosion-proof, low-temperature, and other customized solutions.

Call to Action (CTA)

• Compatibility Consultation: Provide your actuator brand and model to receive verification of adaptation.

• Download Resources: https://www.airtac-shop.com (Product Center - Solenoid Valve - 4M Series)

• Explosion-Proof Solutions: Contact our sales manager for customized Ex explosion-proof rating adaptation schemes.