Highly flexible and compact products for space saving pneumatic circuits

Line on Line – Modular Solenoid Valve Infrastructure for Industrial Pneumatics

Line on Line modules from Metal Work offer a modular platform for the flexible assembly of solenoid valve islands, specifically designed for production environments and machines with high variant diversity. The design allows for the series connection of valve bodies (subbases) in any combination and size, enabling electrical control, pneumatic connections, and mounting features to be standardized and space-optimized for integration into control cabinets, machine frames, or directly onto machine plates.

Materials, Designs, and Sealing Technology

Housings and subbases are predominantly made of high-alloy aluminum with nickel-plated or anodized surfaces for corrosion resistance. Valve bodies are available in various designs: individual valves with integrated connections, multi-valve manifolds with common pressure cylinders, and compact in-line versions with a central pressure connection. Elastomer seals are supplied as standard in NBR (nitrile rubber); for higher chemical resistance or temperature requirements, FKM (Viton) or EPDM are available. Valve seats and internal components use low-wear plastics such as POM or PTFE-coated metals to minimize leakage rates and extend service life.

Connections, Electrical Interfaces, and Mounting Options

The Line on Line platform offers standardized pneumatic connections in metric and imperial variants (G1/8, G1/4, 1/8" NPT) as well as quick connectors for Ø4–12 mm hoses. Electrically, the valves are available with various connectors: M8/M12, DIN connectors, or integrated cables with protection ratings up to IP65/IP67. For easy wiring of sensors and actuators, multi-connectors for fieldbus integration or I/O modules can be mounted upon request. Mounting options include front panel, side mounting, and direct mounting on DIN rails; elastomer bearings and bolts are available for vibration damping.

Technical Data and Operating Parameters

Line on Line solenoid valves are designed for operating pressures typically from 0.2 to 10 bar (up to 16 bar possible depending on the design). Switching speeds are in the millisecond range; flow coefficients (Cv or Kv) vary depending on the cross-section, ranging from approximately Kv 0.1–0.5 for small 2/2-way valves to Kv 0.5–3.0 for larger 5/2- or 5/3-way valves. Operating temperatures cover standard seals from -20 °C to +60 °C, with special seals up to +120 °C. Electrical voltages: 24 V DC, 12 V DC, 110/230 V AC are available; power consumption per coil is specified in the component database and can be reduced using undervoltage or energy-saving coils.

Modularity and Configuration Options

The core feature is the interchangeability of individual valve modules without re-aligning the compressed air supply. Individual stations can be added, swapped, or removed for service without having to dismantle the entire island. Typical combinations include base plates with a central pressure connection, end plates with silencers, intermediate plates with electrical distribution, and manifold plates for regulated secondary circuits. Adapter plates allow the integration of valves of different nominal sizes and functional designs on one line.

Wear, Maintenance, and Leakage Management

With scheduled maintenance, O-ring kits, seal kits, and replacement coils are the most common wear parts. Routine checks should include pressure leak tests, electrical insulation and switching cycle measurements, and inspection of fastenings. For leakage-sensitive applications, the use of metal press-fit seals in conjunction with FKM elastomers and pressure-assisted leak detection is recommended. Documentation of replacement intervals and measurement protocols facilitates traceability and reduces unplanned downtime.

Connection Technology and Integration Notes

During installation, attention should be paid to minimal hose length and short line lengths to minimize pressure losses and reaction delays. Electrical wiring should run in separate channels from power lines; when using M8/M12 connectors, polarity and protection class must be checked. For networked installations, integration into fieldbus systems via suitable gateways is recommended, along with adherence to EMC requirements and protection by appropriate fuses or electronic protection relays.

Typical Industrial Applications

Line on Line modules are used where fast, repeatable switching operations and modular scalability are required. Application areas include assembly machines, packaging machines, robotics cells, tool clamping systems, and conveyor technology. By combining different valve functions (2/2, 3/2, 5/2, 5/3), complex pneumatic sequences can be realized directly at the point of action, simplifying piping and reducing reaction times.

Practical Examples

Functional integration on a filling line: A modular Line on Line island controls the piston carriages for the filling unit. On the base plate, two 5/2-way valves for forward and return stroke are mounted, flanked by 3/2-way impulse valves for fine flow shut-off. Compressed air is supplied via a central pressure regulating valve with integrated filter and manometer; silencers at the ends reduce noise. Electrical control is via M12 connectors on a local I/O module and a PLC output, allowing the entire unit to be quickly dismantled and tested during service.

Low-vibration gripping and positioning station: In a robotics cell, compact Line on Line modules are mounted directly on the gripper. Short hoses minimize latency; special FKM seals ensure use in elevated temperature conditions due to welding processes. An electrical interlock is integrated for emergency stop, which centrally depressurizes all valves in case of a fault and prevents mechanical blockages.

Multiple cycling in packaging machines: In a high-performance packaging machine, several Line on Line modules regulate the cycling of feed flaps, hold-downs, and placement magnets. By using graduated valve sizes, the volume flow is adapted to the respective cylinder cross-sections, which reduces overshoots and extends the service life of the pneumatic actuators. Valve configuration data is stored in the machine documentation, allowing for clear reordering.

Compatibility, Spare Parts, and Accessories

Compatible components include seal kits, silencers, connection blocks, electrical distributors, and air preparation units (filter-regulator-lubricator). For retrofit projects, adapter plates exist to accommodate older solenoid valve series. Replacement coils are available in standard voltages; energy-saving coils reduce heat generation and allow higher packing densities without overheating risk. Technical drawings and exploded views should be used when ordering to identify item numbers. Further technical information and application examples can be found on our support pages: Technology and Application Examples.

Safety, Standards, and Qualification

Line on Line systems must be assembled and operated in accordance with relevant standards. Electrical connections must be designed according to IEC standards, and pneumatic safety elements must comply with ISO 4414. For safety-related functions, a combination with safety valves, redundant control, and diagnostic-capable sensors is recommended. Only qualified maintenance personnel with knowledge of pneumatics and electrical safety may perform work on compressed air networks and valve islands.

• Decision aid: When selecting, consider pressure range, temperature, connection sizes, electrical interfaces, sealing material, and required protection class.

FAQs

1. Which seals are suitable for changing media and higher temperatures?

For chemically aggressive media or elevated temperatures, FKM seals are preferable; EPDM is suitable for aggressive cleaning chemicals and steam, NBR is standard for air and oils up to medium temperatures. Always make the selection based on the medium data sheet and temperature profile.

2. How can I quickly locate leaks on a Line on Line island?

First, shut off compressed air, visually inspect, and tighten connections. A targeted compressed air test with soap solution locates external leaks; for internal leaks, pressure-tested protocols and acoustic leak detectors are suitable. Replacement seals and O-ring kits should be kept in the maintenance pool.

3. What advantages does the modular design offer in a retrofit scenario?

Modularity allows for step-by-step replacement of individual valve sections without re-assembly of large lines. Adapter plates and standardized connections reduce conversion time and downtime risk. Documented assembly and parts lists accelerate spare parts procurement.