Operating in hazardous locations demands more than standard valve performance. Class I (gas/vapor), Class II (dust), and Class III (combustible fibers) environments require equipment that contains every potential source of ignition. ROSS Controls' explosion-proof DM2® Series C valves eliminate the risk of internal spark ignition through encapsulated solenoid coils rated Ex m II T4, combined with CSA, FM, and ATEX certifications that guarantee compliance with North American and European hazardous location standards.

The Safety Imperative

Manufacturing facilities processing flammable liquids, handling combustible dusts, or operating in petrochemical environments face extraordinary safety responsibilities. A single uncontrolled pneumatic discharge can ignite a surrounding explosive atmosphere, resulting in catastrophic injury, facility damage, and regulatory consequences. The DM2® Series C valves address this critical need through redundant safety features and continuous monitoring that ensures safe energy isolation every time—without exception.

Safety-conscious facility managers recognize that preventing incidents requires more than reactive measures. The DM2® Series C's dynamic monitoring function continuously evaluates valve performance during each actuation cycle. If asynchronous movement is detected—where individual valve elements move at different speeds—the valve automatically latches in its safe state, exhausting hazardous pressure to atmosphere. This intelligent design eliminates the most common failure modes in dual-valve safety systems: stuck or sluggish valve elements that compromise safety integrity.

Category 4 PLe/SIL 3 Explosion-Proof Valves Certified for Class I, II & III Hazardous Areas

ROSS Controls backs the DM2® Series C with industry-leading safety certifications. Each valve achieves Category 4 and Performance Level e (PLe) per ISO 13849-1:2015, and Safety Integrity Level 3 (SIL 3) per IEC 61508:2010. These ratings confirm that the valve meets the highest requirements for functional safety in protective systems.

Approvals for Every Major Jurisdiction

The DM2® Series C is certified by CSA (Canadian Standards Association) for use in Class I Division 1 (Groups A, B, C, D) and Class II hazardous locations (Groups E, F, G dust atmospheres). FM (Factory Mutual) approval extends coverage to nonincendive applications in Division 2 areas. For European operations, ATEX certification (Ex m II T4) ensures compliance with EU Directive 2014/34/EU governing equipment in explosive atmospheres.

These comprehensive certifications mean facility managers can deploy DM2® Series C valves across diverse hazardous locations without complex engineering justifications or special variances. The valves are pre-approved for your application—whether you're operating in a petroleum refinery, pharmaceutical manufacturing facility, grain elevator, or chemical processing plant.

Dynamic Monitoring & Asynchronous Detection—Superior Safety Engineering

The technical foundation of DM2® Series C safety performance lies in two innovative design features: dynamic monitoring and asynchronous detection.

Dynamic Monitoring Function

Traditional dual-valve designs rely on periodic external testing to verify valve performance. The DM2® Series C integrates continuous, internal monitoring that evaluates valve operation during every actuation and de-actuation cycle. Specialized orifice chambers and timing circuits continuously evaluate whether both valve elements are responding synchronously. This real-time diagnostic approach catches valve degradation before it becomes a safety risk.

Memory Function Requiring Electrical Reset

When monitoring detects asynchronous operation, the valve latches in its safe (de-actuated) lockout state. Critically, the valve cannot be reset by simply removing and re-applying pneumatic pressure—a vulnerability that exists in some competitor designs. Only an overt electrical reset command from the control system can restore normal operation. This memory function prevents accidental valve reactivation and forces system-level attention to the fault condition.

Residual Pressure Reduction to Near Zero

When the DM2® Series C enters lockout, downstream pressure drops to less than 1% of supply pressure—effectively an immediate vacuum relative to operating conditions. This rapid pressure exhaustion is achieved through internal crossover passages and intelligent poppet sequencing that routes all downstream pressure to the exhaust port. Competing designs often achieve only 5-10% residual pressure, leaving potentially dangerous energy in the system.

Advanced Materials & Construction for Maximum Endurance

ROSS Controls engineers the DM2® Series C from premium materials selected for longevity and reliability in harsh environments:

Cast Aluminum Bodies provide ideal balance between weight, thermal properties, and durability. The aluminum is precision-cast and then ported with tight tolerances to ensure consistent performance across production runs.

Acetal and Stainless Steel Poppets deliver dirt tolerance and wear compensation. The dual-material design prevents galling and ensures rapid response even after thousands of duty cycles in contaminated air systems.

PTFE Backup Piston Rings represent an engineering advancement that extends valve life dramatically. These rings enable trouble-free operation with or without inline lubrication—a flexibility that simplifies installation in diverse industrial environments.

Buna-N Seals provide compatibility across the full operating temperature range (4° to 80°C fluid media) while maintaining pressure integrity under continuous duty operation.

Electrical Integration & Status Feedback

Each DM2® Series C is equipped with primary and reset solenoids rated for continuous duty service. Available in either 24V DC (4.6W) or 120V AC 60Hz (6.8VA) configurations, the solenoids integrate explosion-proof design with responsive actuation characteristics.

An integrated status indicator with dual-contact pressure switch (NO/NC) provides real-time feedback to the control system regarding valve position and readiness. This continuous status feedback enables sophisticated safety monitoring that detects subtle faults before they become hazardous.

Applications & Industries

The DM2® Series C serves critical safety functions in industries worldwide:

Petroleum & Petrochemical: Refineries and processing plants processing flammable liquids and vapors require reliable safe exhaust functionality to support lockout/tagout procedures on hazardous equipment.

Automotive Manufacturing: Press lines and welding cells frequently employ pneumatic actuation in facilities classified for potential explosive atmospheres due to process volatiles or materials handling.

Chemical Manufacturing: Batch processing and pilot plants often operate with flammable chemicals in atmospheric concentrations requiring hazardous location certification.

Pharmaceutical: Facilities manufacturing certain drug compounds require compliance with hazardous location standards, making reliable safe exhaust systems essential.

Grain Handling & Processing: Facilities processing grain, flour, and other combustible dusts classify as Class II hazardous locations under NEC Article 500, demanding equipment rated for dust-ignition-proof operation.

Mining Operations: Both underground and surface facilities frequently require hazardous location equipment to ensure worker safety during emergency response scenarios.

Technical Specifications Summary

The DM2® Series C is manufactured in five basic sizes accommodating flow requirements from 1.7 to 55 Cv NI/min. Operating pressure range of 30-120 psig accommodates most industrial pneumatic systems. Ports are available in NPT (United States/Canada) or G metric (European) threaded configurations.

Response time is determined by pilot pressure and valve size, with intermediate pilots available on sizes 12 and 30 to accelerate response while maintaining identical solenoid power requirements as smaller sizes. All models include high-flow silencers with clog-resistant design and pressure switch status indicators pre-installed.

Implementation & Installation

Successful DM2® Series C integration requires understanding the valve's operating principles and integration with the broader safety system. Base mounting design enables easy valve removal and replacement. Inlet and outlet ports on both sides provide flexible circuit integration and minimize required ductwork modifications.

Installation guidance emphasizes the importance of filtration (5-micron recommended), compatible lubricants, and unrestricted exhaust flow. The DM2® Series C must be integrated into a safety system featuring external monitoring that detects valve faults and prevents machine operation during compromised conditions.

Complete Technical Resources

ROSS Controls provides comprehensive documentation to support system design, installation, and operation. The complete technical datasheet includes dimensional drawings with CAD models available for download. The integrated SISTEMA library enables advanced safety system design and verification.