Quarter-Turn Valve Automation Kits — Everything in One Order

When a manually operated ball or butterfly valve needs to be incorporated into an automatic control system, the solution doesn't always involve replacing it. In most cases, it's enough to add an automation kit: the set of pneumatic and electrical components that transforms the valve into a final actuator controllable from a PLC, SCADA, or local automation panel. At Cematic, we supply these kits with all necessary components, selected to be compatible with each other and with the target valve, under NAMUR (VDI/VDE 3845) and ISO 5211 standards, which guarantee standardized mounting without improvised adapters or mechanical modifications.

Buying automation components separately — an actuator from one supplier, a solenoid from another, limit switches from a third — involves verifying the dimensional compatibility of each interface, calculating the actuator's torque, selecting the correct solenoid size, and finding mounting adapters. With the Cematic kit, that technical work is already done: you receive the correct assembly for your valve and application, ready to install.

What does a Cematic automation kit include?

Kits are configured according to the required level of automation. Available components are:

1. Rack & Pinion Pneumatic Actuator

The heart of the kit. Converts compressed air energy into 90° rotational motion to operate the valve. Made of anodized aluminum with anti-corrosion treatment, available in the following sizes and configurations:

• Double Acting (DA): Compressed air in both chambers. Opens by air and closes by air. Higher torque available in both directions. No torque degradation due to spring fatigue. Requires 5/2 way solenoid.
• Spring Return Normally Closed (SR-NC): Air opens — spring closes. Fail-safe in the closed position. The most requested for chemical dosing, reagent feeding, and safety systems.
• Spring Return Normally Open (SR-NO): Air closes — spring opens. Fail-safe in the open position. For cooling and lubrication services where failure must guarantee flow continuity.
• Torque Range: From 10 Nm (for DN15–DN25 valves) up to 3,000+ Nm (for DN300 and larger valves)
• Working Pressure: 4 to 8 bar
• Ambient Temperature: -20 °C to +80 °C standard
• Valve Interface: ISO 5211 — compatible with all manufacturers that comply with the standard
• Accessory Interface: NAMUR (VDI/VDE 3845) for direct mounting of solenoid and limit switch box without intermediate piping

2. Solenoid Valve (Control Solenoid Valve)

Translates the electrical signal from the control system into compressed air movement towards the actuator. It mounts directly on the NAMUR port of the actuator without the need for additional tubing. Available options:

• 4/2 Way: For single-acting actuators. One energized position (opens) and one de-energized position (closes by spring). The simplest and most reliable design.
• 5/2 Way: For double-acting actuators. Two active positions: one to open and one to close, both air-actuated.
• 5/3 Way Center Blocked: Maintains the valve in its last position in case of electrical signal failure — for applications where "fail-last" is the required safety mode.
• Available Voltages: 24 VDC (most used with modern PLCs), 110 VAC, 220 VAC
• Protection Class: IP65 standard; IP67 for humid environments; ATEX Ex version for classified areas with potentially explosive atmospheres
• Power Consumption: 1.5 to 5 W depending on model — compatible with standard PLC digital outputs without additional power relay

3. Limit Switch Box

Provides position feedback to the control system: confirms whether the valve has fully reached the open or closed position. Without this signal, the PLC cannot verify that the valve responded correctly to its command — a basic safety requirement in any well-designed control loop.

• Electromechanical SPDT Microswitches x2: One for open position, one for closed position. Dry contact signal (NO/NC) to PLC digital inputs. High mechanical reliability, millions of cycle life.
• Inductive Proximity Sensors: No moving parts, no mechanical wear. Ideal for high-frequency cycling applications or environments with vibration. PNP or NPN output as per PLC requirement.
• Visual Position Indicator: Red/green mechanical flag integrated into the box, visible from a distance for verification without instrumentation during inspection rounds.
• Body: Die-cast aluminum with epoxy paint or engineering plastic (PA66) depending on model. Stainless steel version for corrosive environments.
• Protection: IP67 standard; IP68 and ATEX version available.
• Mounting: Directly on the NAMUR interface of the actuator, coupled to the pinion by an adjustable cam that transmits position movement.

4. Air Filter-Regulator (FR Unit)

Conditions the compressed air from the network before it reaches the actuator: filters out moisture and particles, and regulates the pressure to the correct working value (typically 4–6 bar). An actuator operating with dirty air or at incorrect pressure has a drastically reduced service life. The filter-regulator is the lowest cost component with the greatest impact on system longevity.

• 5 or 40 µm filter with transparent collection bowl and manual or automatic drain
• 0–10 bar pressure regulator with glycerine-filled manometer included
• G¼" or G⅜" connection depending on required flow rate

5. Flow Controls / Speed Controllers

Throttling needles installed in the actuator's air ports that allow independent adjustment of opening and closing speeds. Essential for:

• Preventing water hammer in water systems by slowing down valve closure
• Synchronizing operating speed with process sequences
• Reducing mechanical impact on the actuator's end stops, extending its service life

6. Manual Override (Emergency Disengagement)

Mechanism that allows manual operation of the valve in case of actuator or air supply failure, without needing to disassemble the assembly. Available as a direct manual disengagement lever or as an override handwheel with a disengagement cam. Indispensable in critical installations where the valve must be operable under any circumstances.

Standards — why NAMUR and ISO 5211 matter

Interface standardization is what makes it possible to combine components from different manufacturers without adapters. Cematic kits comply with:

• ISO 5211: Defines the mounting interface between the quarter-turn valve and the actuator — dimensions of the mounting flange, position and size of the coupling stem, and bolt pattern. Ensures that any ISO 5211 actuator mounts directly on any ISO 5211 valve of the same size, regardless of the manufacturer.
• NAMUR (VDI/VDE 3845): Defines the interface between the actuator and its control accessories — solenoid, limit switch box, positioner. The NAMUR port on the side of the actuator allows direct mounting of the solenoid without connection tubing, reducing potential leak points and simplifying installation. All NAMUR accessories on the market are interchangeable.
• EN 15714-3: European standard for industrial pneumatic actuators — defines performance requirements, testing, and documentation. Complements ISO 5211 and NAMUR.

Most requested kit configurations

Basic ON/OFF Kit

For simple automation of process valves with command signal and position feedback:

• Pneumatic actuator (single or double acting depending on required fail-safe)
• 4/2 or 5/2 way solenoid valve, 24 VDC or 110 VAC
• Limit switch box with 2 microswitches + visual indicator
• Speed controllers x2
• Filter-regulator with manometer

ON/OFF Kit with Analog Position Control

For continuous position monitoring in SCADA systems or integration with asset management systems:

• All from the basic kit, plus:
• Analog position transmitter 4–20 mA mounted on the NAMUR box
• Continuous position feedback (0% = closed, 100% = open) to the control system

Modulating Kit with Electropneumatic Positioner

For proportional flow, pressure, or level control in a closed-loop PID:

• Double-acting pneumatic actuator (higher torque, higher positioning precision)
• Electropneumatic positioner with 4–20 mA input, proportional response to control signal
• Limit switch box for detecting limit positions
• Filter-regulator with manometer
• Speed controllers

ATEX Kit for Hazardous Areas

For installations in classified areas with flammable gases or dusts (Zone 1, Zone 2, Zone 21, Zone 22):

• Standard pneumatic actuator (intrinsically safe — no electrical components in the body)
• ATEX Ex II 2G certified solenoid
• ATEX Ex II 2G certified limit switch box
• Filter-regulator and stainless steel accessories for corrosive environments

How to select the correct kit for your valve?

To correctly size the actuator and select the appropriate accessories, we need to know:

• Valve type and size (ball or butterfly, nominal diameter)
• Valve manufacturer and model (to verify ISO 5211 interface and required torque)
• Working differential pressure and fluid
• Required fail-safe position: NC (normally closed), NO (normally open), or fail-last
• Available voltage for the solenoid: 24 VDC, 110 VAC, or 220 VAC
• Type of feedback required: dry contact, inductive sensor, or 4–20 mA analog signal
• ATEX classified area? If so, specify zone and gas/dust group
• ON/OFF or modulating control with 4–20 mA signal?

Our technical team performs the complete selection at no additional cost with your application data. Send us the specifications via WhatsApp or to ventas@cematic.com and receive a technical proposal the same business day.

Main industries and applications

• Retrofitting existing valves: Converting manual valves that are already installed and in good condition into automated devices, avoiding the cost of replacing the valve and piping.
• Expansion of control systems: Incorporating new valves into an existing PLC or SCADA in plant expansion projects, adding only the automation kit to the valve order.
• Maintenance and replacement of damaged actuators: Replacing failed actuators, solenoids, or limit switches in existing installations with NAMUR-compatible components, without needing to change the valve or redesign the installation.
• Engineering projects (EPC): Supply of standardized kits for multiple control points in industrial plant construction projects, with complete technical documentation.

Why choose Cematic for your automation kits?

We have stock available in Mexico City in the most demanded sizes and configurations. We perform technical actuator selection with verified torque calculation. We deliver assembled and tested kits when requested as a complete set. We advise on electrical integration with your PLC or control panel. Technical quotation the same business day with detailed specification. Shipping throughout the Mexican Republic. Contact us via WhatsApp or at ventas@cematic.com.