Lockout Valves, 27 Series Piloted Valves with Manual Energy Isolation Lockout L-O-X® Control

Product Overview

The ROSS Controls encompasses the 27 Series Piloted Manual Energy Isolation L-O-X Lockout Valves, a product family that extends the established L-O-X lockout concept with the addition of remote electrical and pneumatic pilot actuation. Where the 15 Series depends entirely on manual handle operation, the 27 Series integrates a pilot-operated poppet valve mechanism that allows the air supply to be turned on or off by electrical solenoid or pneumatic pilot signal when the valve is not physically locked out. The red handle, however, remains the master override: when pushed to the lockable closed position, the handle overrides all remote signals and the valve remains closed and exhausted until the handle is physically pulled to the open position.

The 27 Series covers body sizes from 3/8 inch through 2 inch (up to 2-1/2 inch for select models), with maximum flow capacities reaching Cv 70 (approximately 68,880 Nl/min) in the 2-inch body size. This high-flow capability makes the 27 Series L-O-X the appropriate selection for machine tools, large press systems, multi-actuator transfer lines, and other high-consumption pneumatic circuits where the 15 Series Classic or High-Capacity flow range is insufficient.

Internally, the 27 Series uses proven poppet construction with acetal and stainless steel spool and poppet components, Buna-N seals, and full-size exhaust ports. The poppet design provides dirt tolerance and wear compensation, maintaining consistent performance through extended cycle lives in contaminated plant environments. Fluorocarbon slipper seals on the manual actuation section enable reliable shifting even after prolonged periods without actuation.

All 27 Series L-O-X valves carry Safety Category 1, PL c certification per ISO 13849-1 and SIL 2 per IEC 61508. EAC Declaration of Conformity and CSA/UL certification are available on select models. The integrated 1/8 NPT sensor port accepts the same ROSS pressure switches and pop-up indicators as the 15 Series, enabling consistent sensing accessory standardization across energy isolation installations.

Key Engineering Features

• Piloted Operation with Manual Override Priority - Allows remote on/off control via electrical solenoid (24 VDC, 110 VAC, 230 VAC) or pneumatic pilot when not in the lockout position. The manual red handle always overrides pilot signals: in the lockout (closed) position, no remote signal can open the valve.
• Red Handle Color Coding with Position Indication - Red handle provides immediate visual status: pushed in means supply air blocked and downstream exhausted; pulled out means air supply open. Color and position coding support LOTO procedure auditing at a distance.
• Lockable Only in OFF Position - Handle design prevents padlocking in the open state. Only in the closed position can a padlock be inserted, enforcing the fundamental OSHA lockout/tagout principle that energy isolating devices must be locked in the de-energized position.
• Dirt Tolerant Poppet Construction - 27 Series poppet design is highly tolerant of particulates and contamination in compressed air supplies. Self-cleaning action over poppet seats and wear-compensating geometry maintain consistent response and flow characteristics through millions of cycles.
• High Flow Capacity to Cv 70 - Available in body sizes through 2 inch with Cv up to 70, covering the largest pneumatic machine circuits. Six body sizes (3/8, 3/4, 1-1/4, 2-inch and intermediate sizes) provide selection flexibility across diverse flow requirements.
• Full-Size Exhaust Ports - Exhaust ports are sized equal to or larger than the supply port on all 27 Series variants, ensuring rapid downstream pressure relief during isolation. Threaded exhaust ports accept silencers or remote exhaust lines.
• Fluorocarbon Slipper Seals on Manual Section - Manual actuation section uses Fluorocarbon seals for reliable shifting after long idle periods. Poppet section uses Buna-N seals for normal operating conditions with filtered compressed air.
• Integrated Sensor Port for Pressure Verification - 1/8 NPT sensing port on every variant accepts pop-up indicator 988A30 or pressure switches 586A86 and 1153A30 for visual or electrical zero-energy confirmation before maintenance access.
• SIL 2 and Category 1 / PL c Safety Certification - Certified to Safety Integrity Level 2 per IEC 61508 and Safety Category 1, PL c per ISO 13849-1. Supports machine safety risk assessment documentation under the EU Machinery Directive and equivalent international standards.
• CSA/UL and EAC Certifications - Select 27 Series models carry CSA/UL certification for North American installations and EAC Declaration for CIS market installations, supporting global machine builder compliance needs.

Technical Specifications

General Specifications

Electrical Data (Solenoid Pilot Valves)

Electrical solenoid models are rated for continuous duty. Select voltages available.

Flow Performance Data

Representative flow and dimensional data for 27 Series L-O-X piloted lockout valves. Cv values at standard ROSS test conditions: 100 psig inlet, 10 psi pressure drop, 68 F, 36% RH.

Certifications & Compliance

Typical Applications & Industries

Automotive and Heavy Manufacturing

• Transfer line pneumatic isolation: 27 Series L-O-X valves with electrical solenoid actuation installed on air supplies to multi-station transfer lines allow production supervisors to cycle individual stations off remotely for tooling or jam clearance, while the manual red handle enables maintenance-department lockout independent of PLC control.
• Large press and forging equipment: High-flow 1-1/4 and 2-inch body 27 Series valves handling the pneumatic supply to counterbalance cylinders, die cushions, and air clutch/brake systems on large mechanical and hydraulic presses where OSHA-required energy isolation must cover pneumatic sources in addition to electrical.
• Assembly and test fixtures: Piloted 27 Series valves on air supplies to multi-actuator assembly robots and test fixtures, allowing zone-based on/off control during production and providing padlock-capable lockout during fixture changeovers or end-of-arm tooling replacement.

Metalworking and Machine Tool

• CNC machining center pneumatic supply isolation: 27 Series L-O-X with 3/4 to 1-1/4 inch body sizes mounted on air supplies to spindle tool changers, pallet shuttles, workholding fixtures, and chip conveyor drives, supporting LOTO during tool change maintenance or precision alignment procedures.
• Grinding machine air isolation: Pneumatically piloted 27 Series valves on wheel dresser, coolant, and workholding supplies for cylindrical and centerless grinders where electrical solenoid connections are impractical due to coolant contamination risk but remote on/off control from a PLC is still required.
• Laser and plasma cutting system pneumatic supply: 27 Series valves on assist gas (air) supplies to laser cutting heads and plasma torches, providing both remote shut-off for gas flow control and padlock-capable isolation for nozzle cleaning and lens replacement access.

Packaging and Material Handling

• High-speed packaging line zone isolation: 27 Series 3/8 to 3/4 inch body L-O-X valves on individual zone air supplies in high-speed filling, capping, and labeling lines. Electrically-controlled on/off for production changeovers, manual lockout for machine guarding entry.
• Palletizing and stretch-wrapping systems: Piloted 27 Series valves on pneumatic drives for layer formers, turntable rotation, and film cut-off cylinders, enabling zone-controlled shutdown under PLC command and individual worker lockout for film threading or layer pattern changes.
• Conveyor diverter and sortation systems: 27 Series valves controlling air supplies to pneumatic pop-up sorters, diverters, and stop cylinders in distribution center conveyor systems, where both automated and manual isolation are required.

Chemical and Process Industry

• Pneumatically actuated process valve control: Piloted 27 Series valves upstream of air-to-open or air-to-fail pneumatic actuators on process isolation valves in chemical batch and continuous process systems, providing a LOTO-compliant manual isolation point for actuator maintenance without full system shutdown.
• Compressor and blower auxiliary systems: High-flow 2-inch 27 Series valves on compressed air supplies to control panels, unloading valves, and lube oil systems on industrial compressor packages, where flow demands up to Cv 70 are common and operator-accessible lockout is required for periodic maintenance.

Plastics Processing

• Injection molding machine pneumatic isolation: 27 Series 3/4 and 1-1/4 inch L-O-X valves on air supplies to core pull cylinders, ejector assists, and mold temperature control blowers. Electrical control allows integration into machine safety circuits; manual lockout supports mold maintenance access.
• Blow molding and thermoforming equipment: Piloted 27 Series valves on high-flow air supplies to blow pin cylinders and mold clamping actuators where line pressures are in the 100 to 150 psig range and downstream exhaust must complete rapidly before operator entry into pinch-point areas.

Power Generation and Utilities

• Turbine and generator auxiliary system isolation: High-capacity 2-inch 27 Series L-O-X valves on compressed air supplies to turbine turning gear controls, lube oil mist eliminators, and generator cooler damper actuators. The combination of remote electrical control and padlock-capable manual override satisfies both operational and maintenance isolation requirements in utility plant environments.
• Substation pneumatic control system maintenance: Piloted 27 Series valves on compressed air supplies to pneumatically operated circuit breaker mechanisms and disconnect switches, providing a manually lockable isolation point for breaker maintenance when electrical isolation alone is insufficient.

Ordering and Model Number Configuration

The ROSS 27 Series L-O-X model number encodes the series, function, body size, port size, and actuation type. For G (BSPP) threads, prefix the model number with D. Select body size to match flow requirements; specify actuation type (pneumatic pilot or electrical solenoid) and voltage when applicable.

For G (BSPP) threads on all ports, add prefix D to the model number (e.g., YD2773A3072Z instead of Y2773A3072Z).

Pneumatic pilot models are available for ambient temperatures up to 175 F (80 C); electrical solenoid models are rated to 120 F (50 C) ambient.

Specify voltage suffix when ordering solenoid models: Z for 120 VAC 60 Hz, Y for 230 VAC, W for 24 VDC, H for 12 VDC.

The 2-inch body size requires a minimum operating pressure of 30 psig (2 bar). All smaller body sizes operate at 15 psig (1 bar) minimum.

CSA/UL and EAC certifications are available on select models; specify at time of order if certification documentation is required.

For applications requiring gradual downstream pressure buildup on restart, specify the 27 Series L-O-X with EEZ-ON (1290 Series).

Accessories

Pop-Up Pressure Indicator

Model 988A30. Installs into the 1/8 NPT sensing port. Button pops up visually when downstream pressure is present and retracts at zero pressure, providing simple mechanical zero-energy confirmation.

Pressure Switch (EN 175301-803 Form A Connector)

Model 586A86. Contacts close on falling pressure at 5 psig (0.34 bar). Provides electrical signal to safety PLC or interlock circuit for automated zero-energy confirmation in safety architectures.

Pressure Switch (M12 Connector)

Model 1153A30. M12-connector pressure switch for the sensing port. Contacts close at 5 psig on falling pressure.

Multiple Lockout Device

Model 356A30. Hasp device for group lockout procedures. Provides multiple padlock attachment points so multiple maintenance workers can each apply a personal lock before entering the hazard zone.

Exhaust Silencers

ROSS aluminum silencers for 27 Series exhaust ports, rated to 290 psig.

Warning: Silencers must have flow capacities at least as great as the valve exhaust capacity. Clogged silencers create backpressure that can impair downstream exhaust during isolation.

Related Products & Accessories

• 15 Series Manual Lockout Valves (1287 Series) - Manual-only L-O-X valves for port sizes 1/4 to 2 inch where remote pilot actuation is not required. https://www.rosscontrols.com/en/series/1287-lockout-valves-15-series
• 27 Series L-O-X with EEZ-ON Soft-Start (1290 Series) - Piloted 27 Series lockout valves with integrated soft-start for gradual pressure buildup on restart. https://www.rosscontrols.com/en/series/1290-lockout-valves-with-soft-start-27-series
• 15 Series L-O-X with EEZ-ON (1289 Series) - Manual 15 Series lockout valves with integrated soft-start for smaller port sizes. https://www.rosscontrols.com/en/series/1289-lockout-valves-with-soft-start-15-series
• DM2 Series Double Valves - Redundant safety control valves for Category 4, PL e press control and machine guarding applications. https://www.rosscontrols.com/en/series/dm2-series
• Exhaust Silencers - ROSS aluminum silencers rated to 290 psig for 27 Series exhaust port sizes. https://www.rosscontrols.com/en/series/90-silencers
• 21 Series Directional Control Valves - High-flow inline poppet directional control valves for pneumatic circuit control applications. https://www.rosscontrols.com/en/series/231-low-high-temperatures-classic-21-series

Frequently Asked Questions (FAQ)

Q: What distinguishes the 27 Series L-O-X valve from the 15 Series L-O-X valve?

A: The 15 Series is a purely manual valve operated entirely by the red handle. The 27 Series adds an integral pilot-operated poppet valve stage that allows the air supply to be turned on or off by an electrical solenoid or pneumatic pilot signal when the manual handle is in the open (non-locked) position. This enables the 27 Series to serve dual roles: automated process control during production, and manually-locked energy isolation during maintenance. Both series share the same lockout mechanism, the same sensing port accessories, and both are designated as energy isolation devices, not emergency stop devices. The 27 Series also covers larger port sizes up to 2-1/2 inch and flows up to Cv 70, versus Cv 52 maximum for the 15 Series High-Capacity.

Q: Can the 27 Series L-O-X valve be used as a safety-rated machine control valve?

A: The 27 Series carries Safety Category 1 and PL c per ISO 13849-1 and SIL 2 per IEC 61508 in a singular configuration. These ratings make it appropriate for use as an energy isolation device in documented safety architectures. However, for safety functions requiring higher performance (Category 3 or 4, PL d or e) such as pneumatic press control or guard interlock with spring-return actuation monitoring, the ROSS DM2 Series double valve with integrated monitoring is the appropriate product. The 27 Series is best applied as the energy isolation point at the machine supply, upstream of Category 3 or 4 control valve circuits.

Q: Does the pilot signal override the manual handle position?

A: No. The manual handle always takes priority over the pilot signal. When the red handle is pushed in to the closed and lockable position, the valve remains closed and all downstream air is exhausted regardless of whether a pilot signal is applied. Only after the manual handle is physically pulled to the open position can pilot signals open or close the poppet valve remotely. This priority hierarchy is fundamental to the valve's LOTO function: a maintenance worker's padlock on the handle cannot be defeated by an inadvertent or deliberate pilot signal from the control system.

Q: What is the minimum operating pressure for the 27 Series?

A: For body sizes 3/8 through 1-1/4 inch, the minimum operating pressure is 15 psig (1 bar). For the 2-inch body size, the minimum operating pressure is 30 psig (2 bar) due to the larger poppet mass and spring forces required for reliable actuation at that flow capacity. Verify that inlet supply pressure exceeds the minimum rating for the selected body size under all load conditions, including low-demand periods.

Q: What seal materials are used in the 27 Series L-O-X valve?

A: The poppet valve section uses Buna-N seals for normal compressed air service. The manual actuation section uses Fluorocarbon slipper seals. This combination provides reliable function in standard industrial compressed air environments while enabling smooth manual operation after extended periods without actuation. The temperature range is 40 to 120 F (4 to 50 C) ambient for electrical models and 40 to 175 F (4 to 80 C) for pneumatic pilot models, with media temperature up to 175 F (80 C) for all models.

Q: Are NPT and G (BSPP) thread options available?

A: Yes. Standard models are supplied with NPT threads. For G (BSPP) threads on all ports, prefix the model number with D (e.g., YD2773A3072Z instead of Y2773A3072Z). Both thread types are available across all body sizes and port sizes in the 27 Series line.

Q: What voltage options are available for electrical solenoid models?

A: The 27 Series solenoid models are available in 24 VDC (suffix W), 110/120 VAC 60 Hz (suffix Z), and 230 VAC (suffix Y). Additional voltages including 12 VDC (suffix H) may be available; contact ROSS for specific requirements. All solenoids are rated for continuous duty.

Q: How do I verify that downstream pressure has reached zero before entry?

A: Install the ROSS pop-up indicator model 988A30 in the 1/8 NPT sensing port. The indicator button retracts flush when pressure drops to zero and pops up when pressure is present, providing a simple visual check. For electrical confirmation integrated into a safety control architecture, install pressure switch model 586A86 (EN connector) or 1153A30 (M12), which provide a normally-open contact that closes at 5 psig falling pressure. Both accessories are available from ROSS and install directly into the standard sensing port on every 27 Series variant.

Q: What is the maximum flow capacity of the 27 Series?

A: The largest 27 Series L-O-X variant, the 2-inch body size with 2-inch NPT inlet and 2-1/2 inch exhaust, achieves Cv 70 in both the supply-to-outlet (1-2) and outlet-to-exhaust (2-3) flow directions. This is equivalent to approximately 68,880 Nl/min at standard test conditions, making it one of the highest-flow lockout valves available in a single inline body package.

Q: Can multiple maintenance workers lock out the same 27 Series valve simultaneously?

A: Yes. The ROSS 356A30 multiple lockout device attaches to the valve handle and provides multiple individual padlock attachment points. Each worker applies their own personal padlock, and the valve cannot be restored to the open position until every padlock is removed. This device supports OSHA 1910.147 and ANSI Z244.1 group lockout procedures and is available as an accessory for all 27 Series L-O-X variants.

Q: What is the difference between the pneumatic pilot and electrical solenoid actuation options?

A: Pneumatic pilot models open and close in response to an applied or removed pneumatic pilot signal, typically sourced from a directional control valve in the machine's safety or control circuit. They carry no voltage requirements and can operate in ambient temperatures up to 175 F (80 C), which is the maximum for piloted models. Electrical solenoid models open and close in response to an electrical signal from a PLC output or relay, simplifying wiring in electrically-controlled systems. Solenoid models are rated to 120 F (50 C) ambient. Both actuation types share the same body, poppet mechanism, manual override handle, sensing port, and lockout function.

Q: What is the expected lead time for the 27 Series L-O-X valves?

A: Standard manufacturing lead times for quantities of 10 or fewer units are typically 3 to 4 weeks from the date of order, with shipping available throughout the United States. Many configurations are stocked. Contact ROSS Customer Service at 1-800-GET-ROSS (1-800-438-7677) or visit rosscontrols.com to verify availability for specific model numbers.

Installation & Maintenance Guidelines

• Install the 27 Series L-O-X valve as the first valve in the compressed air supply line to the machine or circuit being isolated, upstream of all control valves, cylinders, and actuators.
• Connect inlet (Port 1) to the upstream supply, outlet (Port 2) to the downstream circuit, and exhaust (Port 3) to atmosphere via a silencer or remote exhaust line.
• Verify that the supply line is adequately sized to avoid pressure drops below the minimum operating threshold (15 psig for 3/8 to 1-1/4 inch body sizes; 30 psig for 2-inch body).
• Do not restrict the exhaust port. Silencers must have flow capacities equal to or greater than the exhaust flow capacity of the valve.
• For pneumatic pilot models, connect the pilot port to a pilot supply at sufficient pressure to actuate the poppet. Pilot supply must equal or exceed the inlet pressure.
• For electrical solenoid models, wire the solenoid coil to the correct voltage and ensure continuous duty rated wiring and connectors are used.
• Install the pop-up indicator (988A30) or pressure switch (586A86 or 1153A30) in the 1/8 NPT sensing port and verify operation before placing in service.
• To padlock the valve closed, push the red handle inward until the valve shifts and downstream air exhausts, then insert the padlock through the lock hole. Pull on the handle to confirm the padlock prevents opening.
• Use the 356A30 multiple lockout device for group lockout with more than one worker.
• Supply filtered compressed air (5-micron filter recommended). The 27 Series poppet design is dirt tolerant, but filtration extends service life and maintains consistent performance.

Warranty & Global Support

ROSS Controls provides a one-year warranty on all 27 Series L-O-X products covering defects in material and workmanship from date of purchase.

Technical support available through ROSS USA at 1-888-TEK-ROSS (1-888-835-7677), or globally through ROSS offices in Canada, Brazil, Germany, France, UK, India, China, and Japan.

Contact ROSS Customer Service at 1-800-GET-ROSS (1-800-438-7677) for order placement, pricing, and availability.

SISTEMA library data for ISO 13849-1 safety calculations is available for download at rosscontrols.com. Contact ROSS Application Engineering for system-level safety architecture support.

Download Catalog: https://www.rosscontrols.com/en/series/1288-lockout-valves-27-series