Compact Solenoid L Series Valves - Standard Temperature Applications -20 to 123 F (-29 to 50 C)

Product Overview

The Automatic Valve Compact Solenoid L Series is a family of 3-way directional control spool valves built on the proven L20 platform, engineered for standard temperature pneumatic applications operating between -20 and 123 F (-29 to 50 C). Available in port sizes from 1/4 inch to 3/8 inch with flow capacity to 1.8 Cv (1,800 Nl/min) and in the L45 body at 1/2 inch with 4.0 Cv (3,940 Nl/min), these valves deliver compact, high-flow directional air control for a wide range of industrial automation, assembly, and process applications.

The L20 Series valves are offered in both inline and manifold-mount configurations, with the L21 variant designed specifically for multi-station manifold assemblies. The balanced spool construction enables ports to be plugged for 2-way or 3-way function, or restricted for low-cost cylinder exhaust speed control without additional components. A wide variety of operators, override options, and electrical connection styles support flexible integration across new and retrofit systems.

The signature Tapered Tee-Seal design differentiates the L Series from conventional spool valves. The bidirectional tee-shaped seal flexes to actively wipe air line sediment from the spool bore on every stroke, eliminating the sticking and contamination-related failures common in standard spool designs. This mechanism is mechanically locked to prevent spiral twist and extrusion, providing reliable sealing across the full operating cycle life. Valves have been tested to SAE specifications with rust and water injected every 864,000 cycles through 20 million total cycles.

The solenoid pilot uses the full air line pressure at port 1 to shift the valve, eliminating dependence on a separate low-pressure pilot circuit. The weather-proof coil is hermetically sealed as an integral watertight molded unit rated NEMA 4X. The pilot is internally supplied when port 1 pressure is 35 to 150 psig; the valve is field-convertible to external pilot supply for installations where inlet pressure may fall below the minimum threshold.

Key Engineering Features

• Balanced Spool Construction - Enables ports to be plugged for 2-way or 3-way function, or restricted for inexpensive cylinder exhaust speed control, maximizing configurability from a single valve body.
• Tapered Tee-Seal Design - Bidirectional tee-shaped seal flexes to wipe air line sediment from the spool on each cycle. Mechanically locked to prevent spiral twist and extrusion, eliminating sticking problems in contaminated environments.
• SAE-Tested 20-Million-Cycle Durability - Proven reliable per SAE specifications with rust and water injection every 864,000 cycles through 20 million cycles, demonstrating long-term performance in harsh industrial conditions.
• Full-Pressure Solenoid Pilot - Three-way pilot uses full air line pressure at port 1 (35 to 150 psig) to shift the valve, ensuring positive, consistent actuation without a separate low-pressure pilot supply.
• Weather-Proof Hermetically Sealed Coils - NEMA 4X rated coil is hermetically sealed as an integral watertight molded unit, providing robust protection in outdoor, washdown, and high-humidity environments.
• Manual Override Standard - Push Non-Locking Override is standard on all solenoid models for commissioning, troubleshooting, and cycle testing without energizing the electrical circuit. Extended Turn and Turn-Locking override options available.
• Field-Convertible External Pilot Supply - Internal-to-external pilot conversion is performed in the field without special tools by rotating the gasket and relocating the pipe plug, supporting low-inlet-pressure applications.
• Inline or Manifold Mount Flexibility - L20 inline body and L21 top-mount manifold body share the same core design, enabling standardization across standalone and multi-station manifold installations.
• Intrinsically-Safe and Explosion-Proof Versions Available - CSA/FM certified explosion-proof and intrinsically-safe (24 VDC only) coil options extend the valve family into hazardous location applications without changing the valve body.
• CE Certified - CE marking per EMC and Low Voltage Directives supports deployment in European machinery and process control applications.

Technical Specifications

General Specifications

Electrical Data (Solenoid Pilot Valves)

Weather-Proof coils are rated NEMA 4X and are suitable for 100% continuous duty. Explosion-Proof coils (CSA/FM) are NEMA 4, 4X, 7C, 7D, 9 rated. All coils are ordered separately and specified by voltage code. Power ratings shown are for weather-proof and explosion-proof types; lower wattage options available on request.

Electrical Connection Options

Flow Performance Data

Certifications & Compliance

Typical Applications & Industries

General Industrial Automation

• Pneumatic cylinder actuation for pick-and-place, clamping, indexing, and positioning systems where compact valve size reduces panel and machine footprint without sacrificing flow capacity.
• Conveyor diverters, pneumatic gates, and material handling sorters requiring reliable, high-cycle directional air control with long service intervals.
• Automated assembly line actuators for joining, pressing, staking, and part transfer operations where 20-million-cycle proven durability reduces maintenance downtime.
• Pneumatic logic and sequencing circuits using 3-way NC and NO configurations to build multi-step automation sequences without programmable control.

Automotive Manufacturing and Assembly

• Body shop tooling, fixture clamping, and weld gun actuation where weather-proof NEMA 4X coils withstand weld spatter, coolant mist, and washdown cycles.
• Paint line and assembly conveyor actuators requiring compact valve bodies that fit tight machine envelopes while providing sufficient flow for fast cylinder response.
• Transfer press automation and stamping line part ejection systems benefiting from the Tee-Seal self-cleaning action in environments with metal particulate contamination.
• Vehicle testing equipment using manifold-mount L21 configurations for multi-circuit pneumatic control in space-constrained test cell environments.

Packaging and Material Handling

• Case erecting, carton sealing, palletizing, and stretch wrapping machinery where compact valve footprint and reliable sealing minimize machine width and maintenance intervals.
• Vacuum cup control for glass, panel, and sheet material handling using 3-way NO configurations to maintain vacuum on power loss as a safety-fail position.
• Labeling, filling, and capping machine actuators requiring precise, repeatable cylinder control in continuous production environments with high daily cycle counts.
• Pneumatic sortation and divert systems where multiple L21 manifold-mount valves consolidate control wiring and air supply into a single, serviceable station.

Food and Beverage Processing

• Packaging line actuators in food facilities where NEMA 4X weather-proof coils and Buna-N seals provide reliable service in washdown environments with cleaning chemicals.
• Filling machine cylinder control and container handling where compact valve size fits into hygienic machine designs without compromising flow or cycle life.
• Conveyor gate and diverter actuation in production facilities requiring valves that tolerate the high-humidity, wet environment typical of food processing plants.
• Can and bottle inspection equipment using multi-station L21 manifold assemblies for centralized valve control with simplified wiring and maintenance access.

Process Control and Industrial Machinery

• Pneumatic actuator control for quarter-turn ball valves, butterfly valves, and damper actuators in process piping systems requiring compact, reliable solenoid pilots.
• Tension control, web handling, and dancer roll systems in printing, converting, and paper processing lines where precise, repeatable air pressure regulation is required.
• Hydraulic press and die casting auxiliary circuits using air-piloted hydraulic directional valves with the L Series as the solenoid pilot stage.
• Machine tool coolant and chip conveyor pneumatic systems requiring compact directional valves with reliable operation in oily, contaminated shop environments.

Outdoor and Weatherproof Installations

• Outdoor pneumatic actuator control panels and remote valve islands where the NEMA 4X hermetically sealed coil provides protection from rain, humidity, and temperature cycling.
• Mobile equipment and vehicle-mounted pneumatic systems requiring compact, lightweight valves that withstand vibration, moisture, and outdoor ambient temperature swings.
• Agricultural equipment pneumatic controls for seeding, spraying, and harvesting machinery operating in dusty, wet field environments with wide daily temperature ranges.
• Infrastructure and utility pneumatic gate and damper control systems where long service intervals and weather resistance are the primary valve selection criteria.

Ordering and Model Number Configuration

Coils are ordered separately from the valve body. Specify the voltage code appended to the coil part number (e.g., 7019-9AA for 120 V AC).

For G (BSPP) threads on all ports, add suffix W to the model number.

For external pilot supply applications (port 1 pressure below 35 psig), add suffix B. Field conversion can also be performed by rotating the internal gasket 180 degrees.

Intrinsically-Safe coils (operator type V) are 24 VDC only and include the connector with the valve. They cannot be used on manifold-mount L21 valves.

Fluoroelastomer seal option (suffix A) is available for lockout valve models only and does not extend the effective temperature range.

Manifold accessories: Blank station cover L21-006; Blocking disk A8020-202. Manifold assemblies available in 2, 4, 6, 8, and 10 station configurations.

Related Products & Accessories

• Compact Solenoid L Series - High Temperature Applications - L Series solenoid spool valves with high-temperature CT coil option rated 0 to 180 F (-18 to 82 C) for elevated ambient applications. https://www.automaticvalve.com/series/2977-compact-solenoid-l-series-valves-high-temperature-applications
• Compact Solenoid L Series - Low Temperature Applications - L Series solenoid spool valves rated -40 to 123 F (-40 to 50 C) for cold storage, refrigeration, and arctic environment installations. https://www.automaticvalve.com/series/2978-compact-solenoid-l-series-valves-low-temperature-applications
• Compact Air Pilot L Series - Standard Temperature - L Series 3-way directional control spool valves with pneumatic pilot actuation for standard temperature applications, no electrical supply required. https://www.automaticvalve.com/series/2995-compact-air-pilot-l-series-valves-standard-temperature
• Compact Air Pilot L Series - Low Temperature - Air pilot L Series spool valves rated to -40 F (-40 C) for cold environment pneumatic circuits without electrical actuation. https://www.automaticvalve.com/series/2996-compact-air-pilot-l-series-valves-low-temperature
• Compact Solenoid L Series - CSA/FM Explosion-Proof, Standard Temperature - L Series valves with CSA and FM certified explosion-proof coils for hazardous location general automation applications. https://www.automaticvalve.com/series/2980-compact-solenoid-l-series-valves-csafm-standard-temperature-applications

Frequently Asked Questions (FAQ)

Q: What is the operating temperature range for the standard temperature L Series solenoid valve?

A: The standard configuration with Buna-N seals and standard coil operates from -20 to 123 F (-29 to 50 C) for both ambient and media conditions. With the high-temperature CT conduit coil option, the range extends to 0 to 180 F (-18 to 82 C).

Q: What flow capacity does the L20 Series provide?

A: The L20 body in 1/4 inch and 3/8 inch port sizes delivers 1.8 Cv (1,800 Nl/min). The L45 body in 1/2 inch delivers 4.0 Cv (3,940 Nl/min). All ratings are for 3-way configurations.

Q: Can the L20 Series valve be used on a manifold?

A: The inline L20 body is not designed for manifold use. The L21 variant shares the same internal design but is configured for top-mount installation on multi-station manifold assemblies (B8023 series, 2 to 10 stations). Intrinsically-Safe coils cannot be used on L21 manifold valves.

Q: What coil connection types are available?

A: Standard coils use DIN EN 175301-803 Form B industrial connectors (NEMA 4X). Options include 18 inch flying leads (Option G), 1/2 inch conduit with 30 inch leads (Option C), high-temperature conduit coil to 82 C (Option CT), explosion-proof 1/2 inch conduit (Option Y for CSA/FM, Option Z for ATEX), and intrinsically-safe with built-in connector (Operator Type V, 24 VDC only).

Q: What voltages are available?

A: Standard voltage codes are AA (110/50, 120/60 V AC), AB (220/50, 240/60, 125 VDC), DA (22/50, 24/60 V AC, 12 VDC), and DB (24 VDC). Lower wattage coil options (2.5 W and 0.7 W) are available on request. All coils are rated for 100 percent continuous duty.

Q: How does the Tee-Seal differ from a standard O-ring seal?

A: The Tapered Tee-Seal is a bidirectional, tee-cross-section elastomeric seal that flexes on each valve stroke to actively wipe air line sediment and contaminants from the spool bore. Unlike O-rings, it is mechanically locked to prevent spiral twist and extrusion, eliminating sticking from contamination. It has been validated to 20 million cycles per SAE rust and water injection testing.

Q: How do I convert from internal to external pilot supply in the field?

A: Remove the solenoid cap and coil from the valve body. Rotate the internal gasket 180 degrees so the gasket covers the internal pilot passage. Reinstall the cap and coil, torquing the M3 screws to 1.02 N-m (9 in-lbs) plus or minus 10 percent. Remove the 1/8 NPTF pipe plug from the cap and connect the external pilot supply to that port.

Q: Is lubrication required for the L Series?

A: Air line lubrication is not required but is recommended for maximum service life. If used, oil must be compatible with Buna-N seal material, ISO 32 viscosity, with an aniline range of 82 to 99 C (180 to 210 F). Filter the lubricant to 50 microns or better.

Q: What is the minimum inlet pressure for solenoid pilot operation?

A: The solenoid pilot is internally supplied when port 1 inlet pressure is 35 to 150 psig (2.4 to 10.3 bar). For applications where inlet pressure may fall below 35 psig, specify Option B for external pilot supply connection, which requires a separate pilot supply of 35 to 150 psig.

Q: Are explosion-proof and intrinsically-safe versions available?

A: Yes. CSA and FM certified explosion-proof coils (Option Y) are available for NEMA 4, 4X, 7C, 7D, 9 / Class I Division 1 Groups A through D installations. ATEX certified explosion-proof coils (Option Z) are available for European hazardous area applications. Intrinsically-safe coils (Operator Type V) are available in 24 VDC only and are certified to CSA/FM Ex ia standards.

Q: What is the typical lead time for L Series valves?

A: Standard manufacturing lead times for quantities of 10 or fewer units are typically 3 to 4 weeks from order placement, with shipping available throughout the United States.

Q: Can the spool be configured for 2-way or 5/2-way function?

A: The 3/2 NC or NO spool can be converted to 2-way function by plugging unused ports. The 5/2-way (double solenoid) function is achieved with a double-body (B design) configuration using two solenoid operators, one at each end of the spool.

Q: What filtration is required for the air supply?

A: Air supply must be filtered to 50 microns or better. For temperatures below 40 F (4 C), the air must also be dried to a dew point below the minimum operating temperature to prevent ice formation inside the valve.

Installation & Maintenance Guidelines

• Mount in any orientation. Ensure adequate clearance around the solenoid cap for manual override access and coil replacement.
• Supply filtered air at 50 microns or better. Air line filtration directly upstream of the valve is recommended to maximize Tee-Seal and spool service life.
• For temperatures below 40 F (4 C), air supply must be dried to a dew point below the minimum operating temperature to prevent ice formation inside the valve.
• Lubrication is not required but is recommended to maximize service life. Use petroleum-based oils compatible with Buna-N seals, ISO 32 viscosity, aniline range 82 to 99 C (180 to 210 F). Filter to 50 microns.
• For internal pilot operation, port 1 inlet pressure must be maintained between 35 and 150 psig at all times during actuation. Pressures below 35 psig require conversion to external pilot supply (Option B).
• For external pilot supply conversion: remove the solenoid cap, rotate the gasket 180 degrees to cover the internal pilot hole, reinstall the cap, and connect the external pilot to the 1/8 NPTF port on the cap. Torque M3 screws to 1.02 N-m (9 in-lbs) plus or minus 10 percent.
• For manifold installations, ensure mounting surface flatness meets dimensional tolerances and that the manifold port thread matches the valve body. Include the 2 seals and mounting hardware supplied with L21 manifold valves.
• Coils are ordered and replaced separately from the valve body. Verify voltage code matches the supply voltage before installation.

Warranty & Global Support

Automatic Valve, a ROSS Controls company, provides a standard warranty on all products covering defects in material and workmanship from date of purchase.

Technical support and product configuration assistance are available through Automatic Valve at (248) 474-6761.

For complete technical data, dimensional drawings, CAD models, and ordering configuration, visit the Automatic Valve product page at automaticvalve.com or contact the factory directly.

Estimated ship dates are based on standard manufacturing times for quantities of 10 or fewer. Shipments are available throughout the United States.

Product Catalog - L Series Compact Inline Valves: https://www.automaticvalve.com/documents/6533/Compact_Inline_Valves_L_Series_AV-IV-L_EN.pdf

Service Instructions - Compact Inline Spool Valves: https://www.automaticvalve.com/documents/405/Compact_Inline_Valves_Service_Information_Form_AV-Compact-IL_OI.pdf