Lockout Valves, 15 Series Manual Energy Isolation L-O-X® Valves

Product Overview

The ROSS Controls encompasses the 15 Series Manual Energy Isolation L-O-X (Lockout and Exhaust) Valves, the industry reference standard for pneumatic LOTO compliance. These 3/2 spool-type valves are purpose-built to block compressed air supply, exhaust all downstream pressure, and accept a standard padlock through a dedicated 0.27-inch lock hole so that maintenance and service personnel can verify zero pneumatic energy before entering a hazard zone.

Available in four sub-families to match the full range of industrial port sizes and flow requirements, the 15 Series covers Slim-Line (1/4 to 3/8 inch, Cv up to 2.67), Modular (1/4 to 3/4 inch, Cv up to 5.6), Classic (3/8 to 1-1/4 inch, Cv up to 19.25), and High-Capacity (1-1/2 to 2 inch, Cv up to 52.23) configurations. Every variant shares a yellow valve body and a red operating handle that provides instant visual confirmation of open or closed state from across a work area.

Internally, the 15 Series uses 316 stainless steel spools with Fluorocarbon slipper seals. The Fluorocarbon seal material resists chemical attack and maintains elastomeric flexibility across the full ambient and media temperature range of 40 to 175 degrees F (4 to 80 degrees C), allowing the valve to shift reliably even after extended periods of inactivity. Exhaust ports are sized equal to or larger than the supply port, ensuring fast downstream pressure relief and providing threaded connections for silencers or remote exhaust lines.

An integrated 1/8 NPT sensing port on each valve body accepts either the ROSS pop-up pressure indicator (model 988A30) or the ROSS pressure switch (model 586A86 or 1153A30) to provide visual or electrical confirmation that downstream pressure has reached zero before personnel begin work. These valves are certified to Safety Category 1 and PL c per ISO 13849-1 and carry EAC Declaration of Conformity for CIS market installations.

ROSS defines these products as energy isolation devices and not emergency stop devices, consistent with OSHA 29 CFR 1910.147, ISO 14118, ANSI B11.19, and ANSI/PMMI B155.1 requirements. They are installed as the first valve in the air supply line to a machine or work zone and are not intended to replace machine control logic or safety-rated stop functions.

Key Engineering Features

• Yellow Body and Red Handle Color Coding - Provides instant visual identification of valve state from a distance. Yellow body identifies the unit as an energy isolation device; red handle position indicates open (pulled out) or closed and lockable (pushed in).
• Dedicated Lock Hole for Padlocking in OFF Position - 0.27-inch diameter, 0.43-inch deep lock hole in the handle mechanism. Design allows padlocking only in the closed (OFF) position to prevent inadvertent opening during maintenance, per OSHA 1910.147 and ISO 14118 requirements.
• Full-Size Exhaust Ports - Exhaust ports are sized equal to or larger than the supply port on every variant, enabling rapid evacuation of downstream air volume. Threaded exhaust ports accept standard silencers or remote exhaust lines.
• Fluorocarbon Slipper Seals - 316 stainless steel spools with Fluorocarbon seals provide reliable shifting even after months of inactivity in low-cycle maintenance isolation applications. Fluorocarbon resists fuel, hydraulic fluid, and many chemical vapors that cause Buna-N seal degradation.
• Integrated Sensing Port for Pressure Verification - 1/8 NPT sensing port on each valve body accepts the ROSS pop-up indicator (988A30) for visual zero-energy confirmation, or pressure switch models 586A86 (EN connector) or 1153A30 (M12) for electrical verification feedback to a safety controller.
• Multiple Sub-Families for Full Port Size Coverage - Slim-Line, Modular, Classic, and High-Capacity sub-families cover port sizes from 1/4 inch through 2 inch NPT and G thread, with flow capacities from Cv 1.84 up to Cv 52.23 (51,000 Nl/min).
• Stainless Steel Spool Construction - 316 stainless steel spool material resists corrosion in humid, wash-down, and chemically aggressive plant environments. Stainless steel construction is standard on all 15 Series L-O-X variants.
• Multiple Lockout Device Accessory - ROSS model 356A30 multiple lockout device allows multiple workers to independently lock out a single valve, enforcing single-point lockout procedures and preventing any one individual from restoring energy without all padlocks being removed.
• Safety Category 1 and PL c Certification - Certified to ISO 13849-1 Category 1, Performance Level c. Suitable for integration into pneumatic safety architectures requiring documented performance level ratings for risk assessments under the EU Machinery Directive and equivalent global standards.
• Detent Mechanism for Open Position - A positive detent holds the handle in the open position, preventing the valve from being bumped closed during normal production operation. The closed position does not have a detent, ensuring the valve can be quickly moved to the isolated position at any time.

Technical Specifications

General Specifications

Flow Performance Data

Flow performance data for 15 Series L-O-X manual lockout valves. All values at standard ROSS CV test conditions: 100 psig inlet, 10 psi pressure drop, 68 F air temperature, 36% relative humidity.

Certifications & Compliance

Typical Applications & Industries

General Industrial Manufacturing

• Pneumatic press isolation: installing a 15 Series L-O-X valve as the first valve upstream of a pneumatic press or stamping machine supply line ensures all cylinder pressure is exhausted and the supply is positively locked before a die change, jam clearance, or maintenance access.
• Conveyor and material handling systems: lockout of air supplies to pneumatic belt tensioners, diverters, and clamping stations during belt replacement or nip-point maintenance activities.
• Robotic work cell energy isolation: mounting a Classic or High-Capacity 15 Series valve on the compressed air drop to a welding or assembly robot cell, padlocking during teach mode entry or end-of-arm tooling changes.
• Machine guarding compliance: using the 15 Series as a documented energy isolation point in formal lockout/tagout written procedures, with the integrated pressure switch providing control-system feedback that the energy source is isolated before a guard interlock can be bypassed for maintenance.

Automotive Assembly and Stamping

• Body shop fixture isolation: Slim-Line and Modular L-O-X valves installed on individual pneumatic circuit drops in high-density welding fixture panels where multiple maintenance workers may be working simultaneously, with the 356A30 multiple lockout device supporting group lockout procedures.
• Paint booth equipment maintenance: Classic 15 Series valves isolating compressed air to spray atomizers, conveyors, and substrate handling equipment during color changeovers and nozzle replacements in spray booths where explosion-proof classification is not required.
• Stamping press counterbalance isolation: High-Capacity L-O-X valves on 1-1/2 to 2 inch air supply lines to counterbalance systems, ensuring large cylinder pressures are fully exhausted before maintenance staff access press slide areas.

Food and Beverage Processing

• Packaging line maintenance: Classic and Modular 15 Series valves on filling, capping, labeling, and sealing machine air supplies, supporting scheduled sanitation LOTO procedures where the same valve may be locked out multiple times per day.
• Washdown environments: Stainless steel 15 Series variants (316 stainless body and spool) for installations in food-grade processing areas where washdown with caustic cleaning agents and water jets is routine.
• Bottling and canning equipment: High-Capacity L-O-X valves on 1-1/2 to 2 inch air mains feeding high-speed beverage lines, where rapid downstream exhaust is essential to minimize downtime during changeovers.

Oil, Gas, and Chemical Processing

• Process equipment maintenance isolation: Classic and High-Capacity 15 Series valves on air supplies to pneumatically actuated process valves, pumps, and compressors that require LOTO before packing replacement, seal service, or line break activities.
• Fluorocarbon seal compatibility: The standard Fluorocarbon seal material provides improved resistance to fuel vapors, hydraulic fluids, and many process chemicals compared to Buna-N, making the 15 Series suitable for plants where trace chemical vapors are present in the supply air.

Pulp, Paper, and Printing

• Printing press pneumatic isolation: Modular and Classic 15 Series valves on air supplies to pneumatic cylinders operating impression cylinders, paper path guides, and ink form rollers, supporting maintenance access during plate changes and blanket washes.
• Paper machine felt and wire changes: High-Capacity L-O-X valves on large-bore air supplies to pneumatic loading arms and shower systems where complete pressure exhaust and zero-energy verification is required before personnel work over moving machine components.

Woodworking and Furniture Manufacturing

• CNC router and machining center isolation: Slim-Line and Modular 15 Series valves on individual pneumatic circuit supplies to vacuum hold-down systems, tool change actuators, and workpiece clamping devices, supporting safe bit changes and collet service.
• Panel press and laminating equipment: Classic 15 Series valves upstream of pneumatic cylinders in hot press and laminating equipment where positive isolation is required before operator access for material loading or platen service.

Ordering and Model Number Configuration

The ROSS 15 Series L-O-X valve model number encodes the sub-family, construction, port size, thread type, and optional accessories. For G (BSPP) threads, prefix the model number with D. Select sub-family and port size to match the required flow capacity and line size.

For G (BSPP) threads on all ports, add prefix D to the model number (e.g., YD1523C5002 instead of Y1523C5002).

Stainless steel body (316 SS) variants are available for Slim-Line and Classic sub-families; model numbers use the B suffix (e.g., D1523B5004 = 3/4 inch G thread, 316 SS body, stainless spool, Fluorocarbon seals).

High-Capacity (1-1/2 and 2 inch) models can be padlocked in two locations: at the handle and at the end of the spool.

The 15 Series High-Capacity variant carries operating pressure up to 300 psig (20.7 bar), suitable for high-pressure distribution lines.

For installations requiring gradual pressure buildup on restart, specify the L-O-X with EEZ-ON option (1289 Series) rather than the standard Series L-O-X valve.

Accessories

Pop-Up Pressure Indicator

Model 988A30. Installs into the 1/8 NPT sensing port on the valve body. The indicator button pops up visually when downstream pressure is present and retracts when pressure reaches zero, providing a simple mechanical zero-energy confirmation without electrical wiring.

Pressure Switch (EN 175301-803 Form A Connector)

Model 586A86. Installs into the 1/8 NPT sensing port. Electrical normally-open contacts close on falling pressure at 5 psig (0.34 bar), providing a signal to a safety PLC or controller that downstream pressure has been removed. Suitable for integration into documented safety architectures.

Pressure Switch (M12 Connector)

Model 1153A30. M12-connector version of the pressure switch for the 1/8 NPT sensing port. Contacts close on falling pressure at 5 psig (0.34 bar). Compatible with M12 fieldbus wiring infrastructure.

Multiple Lockout Device

Model 356A30. A hasp device that attaches to the valve handle and provides multiple individual padlock attachment points. Enables group lockout procedures where multiple workers each apply their own personal padlock, preventing energy restoration until all locks are removed.

Exhaust Silencers

ROSS silencers for all 15 Series exhaust port sizes. Threaded directly into the exhaust port to reduce noise from rapid air discharge during isolation.

Warning: Exhaust silencers must have flow capacities at least as great as the exhaust capacities of the valves. Contaminated or clogged silencers increase back pressure and can impair proper valve operation.

Related Products & Accessories

• 15 Series L-O-X with EEZ-ON Soft-Start (1289 Series) - Combines 15 Series lockout with integrated soft-start gradual pressurization for applications requiring controlled restart after isolation. https://www.rosscontrols.com/en/series/1289-lockout-valves-with-soft-start-15-series
• 27 Series Lockout Valves with Pilot Control (1288 Series) - Piloted L-O-X valves for larger port sizes (up to 2-1/2 inch) with remote electrical or pneumatic actuation in addition to manual lockout. https://www.rosscontrols.com/en/series/1288-lockout-valves-27-series
• 27 Series L-O-X with EEZ-ON Soft-Start (1290 Series) - Piloted lockout valve with soft-start for higher-flow applications requiring remote control and gradual restart. https://www.rosscontrols.com/en/series/1290-lockout-valves-with-soft-start-27-series
• Exhaust Silencers - ROSS aluminum silencers rated to 290 psig for 15 Series exhaust port sizes. https://www.rosscontrols.com/en/series/90-silencers
• 21 Series Directional Control Valves - ROSS poppet inline directional control valves for standard and extreme-temperature pneumatic circuit control. https://www.rosscontrols.com/en/series/231-low-high-temperatures-classic-21-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

Frequently Asked Questions (FAQ)

Q: What is the ROSS L-O-X valve and what does L-O-X stand for?

A: L-O-X stands for Lockout and Exhaust. The ROSS 15 Series L-O-X valve is a manual 3/2 pneumatic valve designed to simultaneously block the compressed air supply and exhaust all downstream pressure when shifted to the closed position. The handle mechanism includes a dedicated lock hole that accepts a standard padlock, physically preventing the valve from being opened while a maintenance worker's lock is in place. This combination of supply isolation, downstream exhaust, and mechanical lockout capability in a single device is what distinguishes L-O-X valves from standard shutoff or ball valves.

Q: Is the 15 Series L-O-X valve an emergency stop device?

A: No. ROSS explicitly designates all L-O-X and L-O-X with EEZ-ON products as energy isolation devices, not emergency stop devices. Emergency stop functions require safety-rated control logic and actuation mechanisms meeting specific response time and monitoring criteria under IEC 60204-1 and ISO 13849. The L-O-X valve is a lockout/tagout (LOTO) device used during planned maintenance to isolate and dissipate stored pneumatic energy, not to stop machine motion in response to a hazard signal.

Q: What OSHA requirements does the 15 Series L-O-X valve support?

A: The 15 Series is designed to support compliance with OSHA 29 CFR 1910.147, Control of Hazardous Energy (Lockout/Tagout). OSHA requires that energy isolating devices be capable of being locked in the de-energized position. The L-O-X valve meets this by providing a lockable handle mechanism that can only be padlocked when the valve is closed and all downstream air is exhausted. The integrated pressure sensing port with optional pressure switch or pop-up indicator supports the OSHA requirement to verify zero energy state before maintenance access begins.

Q: What is the difference between the Slim-Line, Modular, Classic, and High-Capacity sub-families?

A: All four sub-families perform the same 3/2 manual lockout and exhaust function. The differences are in port size range, flow capacity, body design, and operating pressure rating. Slim-Line covers 1/4 to 3/8 inch ports with bar stock aluminum body and 0 to 145 psig rating. Modular covers 1/4 to 3/4 inch with cast aluminum body, 0 to 200 psig, and base-mount capability. Classic covers 3/8 to 1-1/4 inch with cast aluminum body and 0 to 300 psig. High-Capacity covers 1-1/2 to 2 inch with cast aluminum body and 0 to 300 psig, with two lockout locations on the handle and spool end. Select the sub-family whose inlet port size matches the line size of the compressed air supply being isolated.

Q: Why is the exhaust port larger than the inlet on many 15 Series models?

A: Downstream equipment such as cylinders, actuators, and manifolds can store a significant volume of compressed air. When the L-O-X valve is shifted to the closed position, all that stored air must exhaust rapidly through the valve's exhaust port. Sizing the exhaust port equal to or larger than the supply port minimizes the restriction to flow during exhaust, enabling faster pressure relief and reducing the time required to reach zero energy before maintenance can proceed. This design also ensures the exhaust Cv rating meets or exceeds the supply Cv, preventing backpressure buildup during exhaust.

Q: Can the 15 Series L-O-X valve be used in stainless steel wetted-path applications?

A: Yes. ROSS offers 15 Series variants with 316 stainless steel valve bodies in addition to the standard cast aluminum and bar stock aluminum constructions. Both the standard aluminum variants and the stainless steel variants use 316 stainless steel spools and Fluorocarbon seals. The stainless steel body variant is appropriate for food-grade, pharmaceutical, chemical, and washdown environments where the external valve body contacts cleaning agents, sanitizers, or process chemicals. Stainless steel body models carry an EAC Declaration of Conformity; CE certification varies by model.

Q: What accessory provides electrical confirmation of zero downstream pressure?

A: The ROSS pressure switch models 586A86 (EN 175301-803 Form A connector) and 1153A30 (M12 connector) install into the 1/8 NPT sensing port on the valve body. Both switches have normally open contacts that close when downstream pressure falls to 5 psig (0.34 bar). The closed contact signal can be wired to a safety PLC or interlock circuit to provide machine-level confirmation that the pneumatic energy has been removed before a guard door can be unlocked or a maintenance routine can be initiated. The 988A30 pop-up indicator provides the same confirmation visually without electrical wiring.

Q: What is the multiple lockout device and when should it be used?

A: The ROSS 356A30 multiple lockout device is a hasp accessory that attaches to the L-O-X handle and provides attachment points for multiple individual padlocks. In group lockout scenarios where more than one maintenance worker is servicing a machine simultaneously, each worker applies their own personal padlock to the hasp. The valve cannot be restored to the open position until all padlocks are removed, ensuring that no individual can restore energy while others are still in the hazard zone. OSHA 1910.147 and ANSI Z244.1 require that each exposed employee apply a personal lockout device in group lockout situations.

Q: Can the 15 Series L-O-X valve handle elevated operating pressures above 150 psig?

A: Yes. Classic and High-Capacity 15 Series models are rated to 300 psig (20.7 bar). The Modular sub-family is rated to 200 psig (14 bar) and the Slim-Line sub-family to 145 psig (10 bar). For high-pressure distribution systems operating above 150 psig, specify the Classic or High-Capacity sub-family and verify that all downstream components, lines, and fittings are also rated for the maximum system pressure.

Q: What is the temperature rating for the 15 Series L-O-X valves?

A: All 15 Series sub-families share an ambient and media temperature range of 40 to 175 degrees F (4 to 80 degrees C). This range covers the vast majority of indoor industrial environments. For cold-storage or outdoor arctic installations, or for high-temperature process environments above 175 degrees F, consult ROSS for application-specific guidance or alternative product selections.

Q: Is the 15 Series valve suitable for use with oil-free compressed air?

A: Yes. The 15 Series uses Fluorocarbon slipper seals, which do not require air line lubrication. The valve is designed to operate reliably with dry, oil-free filtered compressed air. If downstream components or other valves in the circuit are lubricated, lubrication will not harm the L-O-X valve, but it is not required.

Q: What silencer should I use with the exhaust port of a Classic 15 Series valve?

A: ROSS offers aluminum exhaust silencers sized for all 15 Series exhaust port sizes. For 3/4 inch exhaust ports on Classic models, use silencer 5500A5003 (NPT) or D5500A5003 (G). For 1-1/4 inch exhaust ports, use 5500A7013 (NPT) or D5500A7013 (G). Silencers must be verified to have a flow Cv equal to or greater than the exhaust flow capacity of the valve. Clogged or undersized silencers raise back pressure on the exhaust port and can impair the valve's ability to fully exhaust downstream pressure.

Installation & Maintenance Guidelines

• Install the 15 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 other valves, cylinders, and actuators in the protected zone.
• Connect the inlet (Port 1) to the upstream compressed air supply and the outlet (Port 2) to the downstream circuit. The exhaust (Port 3) should be threaded with a silencer or connected to a remote exhaust line if noise reduction is required.
• Verify that the inlet supply line is adequately sized and does not restrict airflow, as restrictions reduce pressure below valve minimums and can cause erratic operation.
• Do not restrict the exhaust port. Exhaust silencers must have flow capacities at least as great as the exhaust capacity of the valve. A contaminated or undersized silencer creates back pressure that slows downstream exhaust and may prevent the valve from exhausting fully.
• Supply filtered compressed air with a 5-micron filter rating for best valve life. Install a filter upstream of the L-O-X valve to prevent spool and seal contamination.
• Install the pop-up indicator (988A30) or pressure switch (586A86 or 1153A30) in the 1/8 NPT sensing port. Verify the indicator pops up (or switch closes) when pressure is present and retracts (opens) when pressure is absent before relying on it in a lockout procedure.
• To padlock the valve in the closed position, push the handle inward until the valve shifts closed, then insert a padlock through the lock hole in the handle mechanism. Confirm that the handle cannot be pulled out with the padlock in place.
• For group lockout with multiple workers, install the 356A30 multiple lockout device on the handle and have each worker apply their own personal padlock before entering the hazard zone.
• Do not attempt to padlock the valve in the open position. The design intentionally prevents locking in the open state.
• Use only petroleum-based lubricants with an aniline point between 180 and 220 degrees F and ISO 32 or lighter viscosity if any lubrication is used in the pneumatic system. Avoid phosphate-type additives that can degrade valve seals.

Warranty & Global Support

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

Global technical support is available through ROSS offices in the USA (Customer Service: 1-800-GET-ROSS / 1-800-438-7677; Technical Service: 1-888-TEK-ROSS / 1-888-835-7677), Canada, Brazil, Germany, France, United Kingdom, India, China, and Japan.

Contact ROSS Technical Services for application assistance, model selection, and safety architecture integration support at rosscontrols.com or 1-888-TEK-ROSS.

For complete dimensional drawings, installation instructions, and product certifications, visit the ROSS Controls 15 Series product page or download the 15 Series Lockout Valves catalog at rosscontrols.com.

Product Catalog - Lockout Valves: https://www.rosscontrols.com/en/documents/330?filename=Energy_Isolation_Manual_Lockout_L-O-X_Valves_ROSS-LOX_EN.pdf

Installation Instructions - 15 Series Lockout Valves: https://www.rosscontrols.com/en/documents/57?filename=15_Series_Lox_LoxEEZon_Valves_Stuffer_SS123_2023.pdf

Installation Instructions - 15 Series Stainless Steel: https://www.rosscontrols.com/en/documents/58?filename=ROSS_15_Series_Manual_Lockout_LOX_Valves_Stainless_Steel_Installation_Instructions_SS124.pdf