Certified Safety for Hazardous Environments

Every 27 Series valve is engineered to prevent ignition of flammable gases, vapors, liquids, combustible dust, or easily ignitable fibers in classified locations. The product line carries multiple global certifications that validate its suitability for hazardous applications across North America and Europe.

Explosion-proof coils contain any spark originating within the coil or housing, preventing ignition of surrounding flammable materials. These coils carry FM approval for Class I, Division 1, Groups A, B, C, and D; Class II, Division 1, Groups E, F, and G; and Class III locations. CSA certification covers Class I, Division 1 and 2, while ATEX certification includes II 2 G Ex mb IIC T5 for Zone 1 and Zone 2 applications.

Intrinsically safe coils limit electrical energy to levels below ignition thresholds, certified for IS Class I, II, III Division 1, Groups A through G with T5 temperature rating. This design philosophy ensures that even under fault conditions, insufficient energy exists to create sparks or heating effects that could trigger explosions.

Advanced Poppet Design for Maximum Reliability

The 27 Series employs a robust poppet construction that eliminates sliding action, preventing the wear and damage common in spool-style valves. This design creates several competitive advantages for operations managers and maintenance engineers.

Perpendicular poppet face seals generate high-flow capacity while maintaining positive sealing integrity. The differential piston design delivers fast, consistent response times across all operating conditions, while overwhelming shifting forces ensure no-stick operation even after extended periods of dormancy. High-velocity airflow across poppet seats enables self-cleaning action and exceptional dirt tolerance, critical in harsh industrial environments where contaminants could compromise valve performance.

Construction materials include cast aluminum valve bodies for lightweight durability, acetal and stainless steel poppets for chemical resistance, and Buna-N seals for broad media compatibility. These components work within an advanced internal guidance system featuring self-compensating seals that extend service life and reduce total cost of ownership.

Functional Safety Certifications

For safety managers and compliance officers, the 27 Series delivers certified functional safety performance. TÜV Rheinland certification confirms compliance with IEC 61508 and IEC 61511 safety integrity level 2 (SIL 2) requirements. The valves also meet EN ISO 13849-1 performance level c (PL c) in singular applications with HFT = 0, and can achieve SIL 3 and PL e in redundant configurations with HFT ≥ 1.

These ratings provide documented assurance that the valves meet contemporary safety guidelines for control reliability in pneumatic systems, supporting risk assessments and safety validation processes required in modern manufacturing environments.

Comprehensive Valve Configurations

The catalog details three fundamental valve functions to address diverse application requirements:

2/2 Valves (Two-Way, Two-Position)
Available in normally closed and normally open configurations, these valves provide simple on/off control for processes requiring isolation or dumping functions. Flow capacities range from 1.8 Cv (1,800 Nl/min) in compact 3/8" body sizes to 66 Cv (65,000 Nl/min) in large 2-1/2" models, accommodating applications from precision control to high-volume exhaust.

3/2 Valves (Three-Way, Two-Position)
These versatile valves direct flow between inlet and outlet ports while providing a separate exhaust path. The catalog includes detailed flow coefficients for both normally closed and normally open versions, with response time constants (M and F values) that enable precise timing calculations for system design.

4/2 Valves (Four-Way, Two-Position)
Designed for double-acting cylinder control, these valves provide pressurized air to extend and retract actuators. The symmetrical flow paths ensure balanced performance in both directions, with separate inlet, outlet, and exhaust ports for each cylinder chamber.

Technical Specifications & Performance Data

Engineers and system designers will find comprehensive technical data supporting accurate specification and integration. Operating pressure ranges from 15 to 150 psig (1 to 10 bar) for most body sizes, with 2" models requiring a minimum 30 psig (2.1 bar) supply. Temperature ratings support ambient conditions from 40° to 140°F (4° to 60°C) and media temperatures from 40° to 175°F (4° to 80°C), accommodating most industrial environments.

Electrical specifications cover multiple voltage options: 12V DC, 24V DC, 120V AC, and 240V AC. Power consumption varies by coil type, with explosion-proof CSA/FM coils drawing 4.5 watts (DC) or 6.5 VA (AC), ATEX coils requiring 3.5 watts (DC) or 3.3-3.4 VA (AC), and intrinsically safe coils limited to 1.6 watts at 24V DC. All coils carry IP65 enclosure ratings per IEC 60529.

The catalog provides response time formulas (Response Time = M + (F - V)) with specific M and F constants for each valve size, enabling precise calculation of fill and exhaust times based on system volume. This data supports cycle time optimization and performance validation.

Dimensional Data & CAD Models

To streamline mechanical integration, the catalog includes detailed dimensional drawings for each body size and coil configuration. CSA/FM, ATEX, and intrinsically safe versions have slightly different envelope dimensions due to coil housing variations, with all critical measurements provided in both inches and millimeters.

ROSS Controls provides downloadable CAD models for all variants, enabling direct import into design software and accelerating machine design cycles. The drawings clearly indicate mounting hole patterns, port locations, manual override positions, and electrical connection points.

Ordering Information & Model Number Configuration

The comprehensive model number configurator simplifies specification and procurement. Each digit in the model number encodes specific attributes:

• Series identifier (27)
• Valve function (1=2/2 NC, 2=2/2 NO, 3=3/2 NC, 4=3/2 NO, 6=4/2)
• Port thread type (blank=NPT, D=G thread)
• Voltage code (H=12V DC, W=24V DC, Z=120V AC, Y=240V AC)
• Body and port size (200 series through 906 series)
• Coil certification (blank=Explosion-Proof CSA/FM, A=ATEX, N=Intrinsically Safe)
• Seal material (B=Buna-N standard)

This systematic approach ensures accurate ordering and eliminates ambiguity in communication between engineering, purchasing, and supplier teams.

Accessories & Conversion Kits

The catalog extends beyond valves to include essential accessories. Exhaust silencers in aluminum construction reduce noise while managing flow capacities from 6.8 Cv to 104 Cv. Hex nipples facilitate connection adaptation, while solenoid pilot conversion kits enable field conversion of standard poppet valves to explosion-proof configurations, protecting existing equipment investments.

Installation & Safety Guidelines

ROSS emphasizes critical pre-installation and service requirements. All energy sources must be locked out per OSHA 1910.147 and EN 1037 before servicing. The catalog stresses the importance of 5-micron filtration to maximize valve life and performance, and warns against phosphate-type additives that can damage polyurethane components.

Exhaust restrictions must be avoided, and silencers must have flow capacities equal to or greater than valve exhaust capacities to prevent backpressure that could compromise operation. For safety applications involving hazardous machinery, the catalog references the need for monitoring systems that detect valve failures and inhibit further operation.

Global Support & Warranty Coverage

ROSS Controls maintains a worldwide network of fluid power experts across the Americas, Europe, and Asia-Pacific regions, providing local technical support, safety training, and application engineering. The 27 Series carries a one-year warranty against defects in material and workmanship, with the caveat that warranties become void if products are subject to misuse, misapplication, improper maintenance, modification, or tampering.

Target Industries & Applications

These valves serve critical roles across multiple sectors:

• Chemical processing plants handling flammable solvents and gases
• Oil & gas extraction and refining operations
• Mining equipment operating in dusty, potentially explosive atmospheres
• Pharmaceutical manufacturing requiring both safety and cleanliness
• Food & beverage processing with combustible dust hazards
• Automotive paint booths and assembly operations
• Aerospace manufacturing facilities
• Metal processing including aluminum smelters and steel mills

The 27 Series addresses the unique requirements of each industry while maintaining standardized interfaces and certifications that simplify global deployment.

Download the Complete Technical Catalog

Access the full ROSS-27-HL catalog to explore detailed dimensional drawings, flow charts, response time calculations, and complete model number configuration tables. The document includes safety warnings, installation instructions, and maintenance guidelines essential for proper implementation in hazardous location applications.

Download the PDF now to access comprehensive technical data, certification details, and ordering information for the complete 27 Series explosion-proof and intrinsically safe valve portfolio.