27 Series Soft Start EEZ-ON Valve Safety Category. 1, PLc

Product Overview

The ROSS Controls 27 Series Soft Start EEZ-ON Valve provides controlled, gradual downstream pressure buildup when a pneumatic system is first energized or re-energized after an emergency stop or safety gate open. By limiting the rate at which full line pressure reaches downstream actuators, the EEZ-ON valve prevents sudden, hazardous cylinder extension and equipment movement at machine startup, satisfying Safety Category 1 and Performance Level c (PL c) requirements per ISO 13849-1.

Built on the proven 27 Series poppet valve platform, the EEZ-ON valve incorporates an adjustable internal restriction that controls the rate of downstream pressure buildup. The operator or maintenance technician sets the restriction to match the specific load and cycle time requirements of the machine. Once downstream pressure reaches the valve's switching threshold, the full-flow path opens automatically to supply line pressure for normal operation.

The 3/2 EEZ-ON valve function includes a full-size exhaust port equal to or larger than the supply port, ensuring rapid and unrestricted downstream depressurization when the valve is de-energized. This eliminates the need for a separate shut-off valve to isolate supply while exhausting downstream air. Available in pressure-controlled (pneumatic pilot) actuation with single solenoid options, the EEZ-ON valve operates within a pressure range of 15 to 150 psig (1 to 10 bar).

The 27 Series EEZ-ON is available in port sizes from 3/8 inch to 1-1/4 inch with flow coefficients from 3.8 Cv to 24 Cv, covering a wide range of pneumatic system sizes. Both NPT and G (BSPP) thread options are available. Flush, flexible, non-locking manual overrides are standard on single solenoid models for commissioning and troubleshooting.

Key Engineering Features

• Gradual Pressure Buildup Control - Adjustable internal restriction determines the rate of downstream pressure buildup, allowing slow, controlled cylinder movement into normal working positions before full line pressure is applied. This prevents hazardous rapid equipment movement at startup.
• Adjustable Time Delay - The same adjustable restriction that controls pressure buildup rate also sets the effective time delay before full system pressure is reached. Engineers can tune this delay to match machine-specific startup requirements.
• Full-Size Exhaust Port - Exhaust port is equal to or larger than the supply port, providing unrestricted downstream air exhaust when the valve de-energizes. No separate shut-off valve is needed in the circuit.
• Dirt Tolerant Poppet Design - 27 Series poppet construction provides wear-compensating performance and inherent dirt tolerance, maintaining reliable operation across millions of cycles even in contaminated compressed air environments.
• Non-Locking Manual Override - Flush, flexible manual override buttons are standard on single solenoid models for circuit commissioning, troubleshooting, and valve function verification without removing the valve from the line.
• Safety Category 1 PL c - The EEZ-ON valve is rated Safety Category 1, Performance Level c per ISO 13849-1, confirming its suitability for pneumatic safety startup control circuits on machinery requiring defined risk reduction.
• SIL 2 Safety Integrity Level - TUV-recognized SIL 2 safety integrity level for use in functional safety architectures per IEC 62061.
• Threaded Exhaust Ports for Silencers or Remote Exhaust - Exhaust ports are threaded to accept standard exhaust silencers or remote exhaust line fittings, allowing noise reduction and directed exhaust routing in enclosed or noise-sensitive installations.
• Compact Inline Mounting - Inline body design allows installation in existing pneumatic lines without manifold modifications. Compatible with NPT and G (BSPP) port threads in multiple body sizes.

Technical Specifications

General Specifications

Flow Performance Data

Flow coefficient and dimensional data for 27 Series EEZ-ON soft start valves by body size. Ports 2-3 flow refers to exhaust path (3/2 configurations).

Certifications & Compliance

Typical Applications & Industries

Machine Tool and Metal Fabrication Startup Control

• Gradual re-pressurization of pneumatic clamping and fixture cylinders on CNC machining centers and turning centers after emergency stops, preventing parts from being ejected by sudden cylinder extension.
• Controlled pressure buildup on pneumatic chuck actuators and tailstock cylinders on lathes and grinding machines at startup, protecting operators from unexpected workpiece movement.
• Soft start of pneumatic quill feeds and drill head advance actuators on drill press lines where full-pressure rapid advance at startup could damage tooling or workpieces.
• Re-pressurization sequencing on multi-station transfer machines after safety gate cycles, ensuring cylinders reach their home positions in a controlled, predictable manner.

Pneumatic Press and Forming Operations

• Soft start pressure supply to pneumatic power presses and punch presses where gradual pressure buildup after a stop condition allows the press cylinder to move slowly to home position before full press force is restored.
• Controlled re-pressurization on hydraulic press pneumatic pilot circuits to prevent unintended rapid descent of press rams after emergency stop or guard open events.
• Air cushion circuit startup control on deep-draw forming presses where sudden pressure application can cause die damage or material tearing.

Automated Assembly and Pick-and-Place Systems

• Soft start of pneumatic pick-and-place units on assembly lines after safety light curtain interruptions, allowing robot arms and SCARA units to return to home position without rapid air-driven extension.
• Controlled startup of multi-axis pneumatic indexing tables where sudden full-pressure actuation at restart could cause part misalignment or fixture damage.
• Gradual pressure application to pneumatic gripper actuators on assembly robots where part slippage at startup could result in dropped parts or equipment damage.

Packaging and Material Handling

• Soft start of pneumatic cylinder drives on case erectors, carton openers, and palletizing stations after product jams or guard interventions, preventing sudden arm extension into the work zone.
• Controlled re-pressurization of pneumatic transfer conveyors and diverter actuators after emergency stops on packaging lines.
• Gradual startup of pneumatic bagging and filling machine actuators where abrupt cylinder extension could damage product or machine components.

Food and Beverage Processing Equipment

• Soft start of pneumatic fill valves and product discharge actuators on bottling, canning, and filling machines after CIP (Clean-In-Place) cycles or guard access events.
• Controlled pressure buildup on pneumatic cut-off and portioning actuators on food slicing and processing lines where sudden actuation at startup could result in product waste or equipment damage.
• Gradual re-pressurization of pneumatic seal bars and forming dies on form-fill-seal packaging machines after safety stops.

General Industrial Pneumatic Systems

• System-level soft start for entire pneumatic distribution branches that were fully exhausted during maintenance lockout, preventing simultaneous full-pressure actuation of all connected cylinders at startup.
• Controlled startup on pneumatic actuators in outdoor or cold-climate installations where sudden full-pressure application to stiff seals and cold cylinders can cause accelerated wear.
• Soft start of pneumatic actuators on test stands and specialty machinery where repeatable, controlled startup pressure curves are required for consistent test results.

Ordering and Model Number Configuration

27 Series EEZ-ON valves use a structured model number system based on body size, thread type, and actuation. Example model number: 2781A3007 (3/8 inch NPT, pneumatic actuation).

Body size codes: 3 = 3/8 inch, 5 = 3/4 inch, 6 = 1-1/4 inch.

For G (BSPP) threads, add 'D' as a prefix to the model number (e.g., D2781A6007).

Non-locking manual override is standard on single solenoid actuation models.

Exhaust ports are threaded for silencer or remote exhaust line installation. Specify silencer model separately if required.

Accessories

Exhaust Silencers

Threaded exhaust silencers are available for all EEZ-ON valve exhaust port sizes to reduce noise in startup exhaust events. Silencer flow capacity must equal or exceed the valve exhaust flow capacity. Contaminated silencers can cause back pressure that affects valve operation and soft start timing.

Remote Exhaust Fittings

Threaded fittings allow the exhaust port to be piped to a remote location for applications where exhaust air must be directed away from the operator area or vented outdoors.

Related Products & Accessories

• SV27 Series Sensing Valve (Category 2 PL c) - 27 Series poppet valve with DPST feedback switch for Safety Category 2 PL c monitoring applications. https://www.rosscontrols.com/en/series/1298-directional-control-valve-sv27-series
• RSe Series Double Valve (Category 4 PL e) - Redundant spool double valve with external monitoring and automatic reset for the highest safety levels. https://www.rosscontrols.com/en/series/1300-rse-series-double-valve
• 77 Series Double Valve (Category 4 PL e) - Internally monitored pressure-controlled double valve with automatic reset. https://www.rosscontrols.com/en/series/1301-77-series-double-valve
• CrossMirror CM26 Series (Category 4 PL e) - Self-monitoring double valve with manual lockout reset for Category 4 PL e applications. https://www.rosscontrols.com/en/series/1302-crossmirror-cm26-series-double-valves
• 27 Series Classic Directional Control Valves - Standard 27 Series poppet valves for general pneumatic directional control without safety sensing. https://www.rosscontrols.com/en/series/230-standard-temperatures-classic-27-series
• Exhaust Silencers - Threaded aluminum silencers for EEZ-ON exhaust ports. https://www.rosscontrols.com/en/series/90-silencers

Frequently Asked Questions (FAQ)

Q: What does the EEZ-ON valve actually do at machine startup?

A: When the EEZ-ON valve is first energized or re-energized after a safety stop, the adjustable internal restriction limits the rate at which compressed air reaches downstream actuators. This causes cylinders to move slowly and more safely toward their normal working positions. Once downstream pressure builds to the switching threshold, the valve's full-flow path opens automatically to supply normal line pressure for the production cycle.

Q: How is the pressure buildup rate adjusted?

A: An adjustable restriction internal to the EEZ-ON valve controls the rate of downstream pressure rise. Turning the adjustment increases or decreases the restriction orifice, directly setting how quickly downstream pressure builds from zero to full line pressure. This adjustment also controls the time delay before full system pressure is restored.

Q: Does the EEZ-ON valve require a separate shut-off valve to isolate supply?

A: No. The 3/2 EEZ-ON valve function includes a full-size exhaust port that actively exhausts downstream air when the valve is de-energized. Supply is positively shut off at the same time, so no separate shut-off valve is required in the circuit.

Q: What safety ratings does the EEZ-ON valve carry?

A: The 27 Series EEZ-ON valve is rated Safety Category 1, Performance Level c (PL c) per ISO 13849-1 and Safety Integrity Level 2 (SIL 2) per IEC 62061. These ratings confirm the valve's suitability for use in safety-related startup control circuits on industrial machinery.

Q: What is the operating pressure range?

A: The EEZ-ON valve operates from 15 to 150 psig (1 to 10 bar). The 15 psig minimum is lower than standard directional control valves, providing reliable soft start function at lower system pressures.

Q: What port sizes and flow coefficients are available?

A: The EEZ-ON valve is available in 3/8 inch, 3/4 inch, and 1-1/4 inch body sizes. Flow coefficients range from 3.8 Cv (3,739 Nl/min) for the 3/8 inch body to 24 Cv (23,616 Nl/min) for the 1-1/4 inch body, covering most industrial pneumatic system capacities.

Q: What temperature range does the EEZ-ON valve support?

A: Both ambient and media temperature ranges are 40 to 175 F (4 to 80 C), covering standard industrial and moderate-temperature processing environments with Buna-N seals.

Q: Can the exhaust port be used with a silencer?

A: Yes. All EEZ-ON exhaust ports are threaded to accept standard exhaust silencers or remote exhaust fittings. The silencer flow capacity must equal or exceed the valve exhaust capacity. A silencer that is too restrictive will cause back pressure that interferes with downstream depressurization and soft start timing.

Q: Is a manual override available on the EEZ-ON valve?

A: Flush, flexible, non-locking manual override buttons are standard on single solenoid actuation EEZ-ON models. Manual overrides allow commissioning, troubleshooting, and function verification without electrical signals. The non-locking design prevents the valve from being inadvertently held in the actuated position.

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

A: Yes. Standard models ship with NPT threads. To order with G (BSPP) threads, add 'D' as a prefix to the model number (e.g., D2781A3007).

Q: What filtration is required for the supply air?

A: Filtered compressed air is required. The 27 Series spool design provides inherent dirt tolerance, but clean, filtered air maximizes valve life and minimizes wear on spool seals. 5-micron filtration is recommended.

Q: How does the EEZ-ON valve interact with an emergency stop circuit?

A: In a typical safety circuit, the EEZ-ON valve is de-energized when the emergency stop is activated, causing immediate downstream exhaust of all actuators. When the emergency stop is reset and the machine is re-started, the EEZ-ON valve re-energizes and provides the controlled gradual pressure buildup before full system pressure is restored, preventing rapid motion of actuators during the startup sequence.

Installation & Maintenance Guidelines

• Install the EEZ-ON valve inline between the main supply valve and the downstream actuators. Mounting in any orientation is acceptable; vertical mounting is preferred.
• Set the adjustable restriction before energizing the system. Begin with a moderate restriction setting and test the pressure buildup rate by observing cylinder motion during a startup cycle. Adjust as needed to achieve smooth, controlled actuator movement.
• Ensure the exhaust port is not restricted. A restricted or blocked exhaust will prevent downstream air from venting when the valve de-energizes, which could result in the actuators failing to retract.
• Threaded exhaust ports accept standard silencers or remote exhaust fittings. Confirm that the silencer or remote line flow capacity is equal to or greater than the valve exhaust flow capacity.
• Supply filtered air at 5-micron filtration minimum. Water-saturated or contaminated air will cause premature spool seal wear and erratic restriction adjustment.
• Operating pressure must be within 15 to 150 psig (1 to 10 bar). Pressures below 15 psig may result in incomplete valve opening or unreliable soft start function.
• Verify ambient temperature is within the rated range of 40 to 175 F (4 to 80 C). Installations in cold environments below 40 F require special attention to compressed air dryness to prevent ice formation.
• After installation, perform a complete startup sequence test. Confirm that downstream cylinders move slowly from their home positions before full pressure is applied, and that full pressure is achieved within the expected time delay.
• Document the restriction setting for maintenance records. If the EEZ-ON valve is ever replaced or serviced, the restriction must be reset to the documented setting to restore the correct startup behavior.

Warranty & Global Support

ROSS Controls provides a one-year warranty on all 27 Series EEZ-ON products, covering defects in material and workmanship from the date of purchase.

Technical support for EEZ-ON valve selection, adjustment, and safety circuit integration is available from ROSS Controls USA at (800) 438-7677 or +1-248-764-1800.

Global ROSS offices provide local technical support in the USA (Ferndale, Michigan headquarters), Canada, Brazil, Germany, France, United Kingdom, India, China, and Japan.

For dimensional drawings, CAD models, and safety certification documentation, visit the EEZ-ON Series product page at rosscontrols.com.

Download Catalog: https://www.rosscontrols.com/en/series/1299-27-series-soft-start-eez-on-valve