DM2 Series C Safe Exhaust Valve, Explosion Proof Safety Category 4 PL e, Internal Monitoring with Reset

Name: DM2 Series C Safe Exhaust Valve, Explosion Proof
Brand: ROSS Controls

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Product Catalog

Installation Instructions

Monitoring, and air flow control functions are simply integrated into two identical valve elements
Asynchronous movement of valve elements is detected by the dynamic monitoring and the valve latches in the safe condition, resulting in a residual outlet pressure of less than 1% of supply
Reset can only be accomplished by the integrated electrical (solenoid) reset; the valve cannot be reset by removing and re-applying supply pressure
Poppet design that is dirt tolerant, wear compensating for quick response and high flow capacity
Explosion-proof Coils contain any spark originating from within the coil or housing preventing the ignition of any flammable material in the surrounding environment, resulting in a larger explosion
Includes a pressure switch with both normally open (NO) and normally closed (NC) contacts to provide status feedback to the control system indicating whether the valve is in the lockout or ready-to-run condition
Inlet and outlet ports on both sides provide for flexible piping (plugs for unused ports included)
SISTEMA Library available for download

DM2 Series C Safe Exhaust Valve, Explosion Proof Product Overview

The DM2® Series C Safe Exhaust valves are dual valves used to block the supply and remove the downstream pressure from the circuit or machine. It is integrated into the electrical safety system to remove potentially hazardous energy in order to provide employees safe access to a machine or zone. By quickly removing the pneumatic energy with a safety valve, determined by the risk assessment, the safety system integrity is maintained allowing the employee to complete their tasks safely and rapidly.

Please refer to the side and below for links to easily navigate and download ROSS Controls DM2 Series C Safe Exhaust Valve, Explosion Proof catalogs, installation instructions, and technical data. Additionally, you have the option to filter through all available options to DM2 Series C Safe Exhaust Valve, Explosion Proof variant that meets your requirements.

Series Overview ❯

Product Overview

The ROSS Controls DM2 Series C Safe Exhaust Valve, Explosion Proof is a redundant dual-poppet safe exhaust double valve designed for hazardous location installations where explosive or flammable atmospheres are present. The valve achieves Safety Category 4, Performance Level e (PL e) per ISO 13849-1:2015 and SIL 3 per IEC 62061, with DGUV functional safety certification, making it the complete solution for personnel protection in environments where pneumatic energy must be safely removed and where ignition prevention is critical.

The explosion-proof coils are the defining feature of this series. They are designed to contain any spark originating from within the coil or coil housing, preventing ignition of any flammable or explosive material in the surrounding environment that would otherwise result in a larger explosion. The coils use conduit wiring connections rather than quick-disconnect DIN or M12 connectors, providing the sealed electrical enclosure required for hazardous location compliance. This makes the DM2 Series C Explosion Proof the appropriate selection for any pneumatic safety application in NEC Class I (flammable gases and vapors) or NEC Class II (combustible dust) classified areas.

The valve uses internal dynamic monitoring: the two identical valve elements are monitored continuously for synchronous operation. If asynchronous movement is detected, the monitoring latches the valve in the safe (exhausted) condition with residual outlet pressure of less than 1 percent of supply. Reset from the latched fault condition is accomplished exclusively via the integrated electrical solenoid reset. The valve cannot be reset by removing and re-applying supply pressure, mirroring the DM2C Series C's deliberate fault-memory design to ensure that faults are acknowledged and investigated before machine restart.

Status feedback is provided by a mechanical pressure switch with both normally open (NO) and normally closed (NC) contacts, reporting locked-out or ready-to-run valve status to the machine safety control system. The feedback switch uses an EN 175301-803 Form A connection for field wiring.

The DM2 Series C Explosion Proof is available in multiple body sizes covering flow capacities from 3 Cv (1/2 inch ports) and above. Inlet and outlet ports are provided on both sides for flexible piping, with plugs for unused ports. Base-mounted design with captive screws enables field valve replacement without disturbing piping. SISTEMA Library files are available for download. Certifications include DGUV, CE, and EAC.

Key Engineering Features

Explosion-Proof Solenoid Coils - Coils designed to contain any internal spark or arc within the coil housing, preventing ignition of surrounding flammable or explosive atmospheres. Required for NEC Class I (flammable gases/vapors) and Class II (combustible dust) classified locations.
Safety Category 4, PL e (ISO 13849-1:2015) - Highest achievable pneumatic valve safety category when integrated with proper safety controls, providing maximum risk reduction for personnel in hazardous areas.
SIL 3 (IEC 62061) and DGUV Certified - Third-party certified SIL 3 safety integrity level and DGUV functional safety certification for European and North American hazardous location compliance.
Internal Dynamic Monitoring - Integrated monitoring verifies synchronous movement of both valve elements on every cycle. Asynchronous movement triggers immediate latching to the safe state with residual outlet pressure less than 1% of supply.
Solenoid Reset Only (Fault-Latching) - Reset from the latched fault condition is accomplished exclusively by the integrated solenoid reset. Supply pressure removal and reapplication does not reset the valve, ensuring operator fault investigation before machine restart.
Conduit Wiring for Sealed Electrical Enclosure - Lead-wire connections with conduit fittings (no DIN or M12 quick-disconnect connectors) provide the sealed electrical enclosure required for explosion-proof solenoid coils in hazardous locations.
Mechanical Pressure Switch Feedback - NO and NC pressure switch contacts report ready-to-run or locked-out valve status to the machine safety controller.
Dual-Poppet Redundant Design - Two identical valve elements in tandem ensure that a single element failure cannot prevent the safety exhaust function from executing.
PTFE Backup Piston Rings - Extends valve durability and enables operation with or without in-line lubrication.
Base Mount with Captive Screws - Valve replacement without disturbing field piping. Inlet and outlet ports on both sides with plugs for unused ports.
SISTEMA Library Support - Downloadable SISTEMA Library files for ISO 13849-1 Category 4, PL e documentation.

Technical Specifications

General Specifications

Parameter	Specification
Safety Category	Category 4
Performance Level	PL e per ISO 13849-1:2015
Safety Integrity Level	SIL 3 per IEC 62061
Monitoring Type	Internal dynamic monitoring
Reset Type	Solenoid reset only; cannot reset by pressure removal/reapplication
Residual Outlet Pressure (fault condition)	Less than 1% of supply pressure
Valve Function	Redundant 3/2 single solenoid
Construction	Dual poppet
Actuation	Electrical (explosion-proof solenoid), 24 VDC
Coil Type	Explosion-proof (spark-containing) coils
Solenoid Connection	Lead wires with conduit fitting (not DIN or M12 quick-disconnect)
Feedback Type	Mechanical pressure switch, NO and NC contacts
Feedback Switch Rating	0.1 A / 125-VAC; 0.1 A / 30 VDC; 0.3 A / 60 VDC
Feedback Connection	EN 175301-803 Form A
Power Consumption	15 watts
Voltage	24 VDC
Operating Pressure Max	120 psig (8.3 bar)
Pilot Supply	Internal
Example Port Sizes (Size 4)	1/2" inlet / 1/2" outlet / 1/2" exhaust
Flow (Size 4, Ports 1-2)	3 Cv (2,952 Nl/min)
Flow (Size 4, Ports 2-3 exhaust)	6.5 Cv (6,396 Nl/min)
Mounting	Base mount
Thread Type	NPT
Ambient Temperature	15 to 122 F (-10 to 50 C)
Media Temperature	40 to 175 F (4 to 80 C)
Flow Media	Filtered, lubricated or unlubricated (mineral oils per DIN 51519, viscosity classes 32-46)
Valve Body Material	Cast aluminum
Poppet/Spool Material	Acetal and stainless steel
Seal Material	Buna-N
Piston Rings	PTFE backup
Certifications	DGUV, CE, EAC

Certifications & Compliance

Certification/Standard	Detail
Safety Category / PL	Category 4, PL e per ISO 13849-1:2015 when integrated with proper safety controls.
Safety Integrity Level	SIL 3 per IEC 62061.
DGUV Certification	DGUV certified for European industrial safety applications.
CE Marking	CE marked per EU Machinery Directive 2006/42/EC.
EAC Declaration	EAC declaration for Eurasian Economic Union markets.
Explosion-Proof Coil Design	Coils engineered to contain internal sparks and prevent ignition of surrounding flammable atmospheres. For NEC Class I and Class II hazardous location compliance.
SISTEMA Library	Downloadable SISTEMA Library files for ISO 13849-1 Category 4, PL e documentation.

Typical Applications & Industries

Oil and Gas Production and Processing

Wellhead and upstream production equipment where pneumatic actuators control safety-critical valves in NEC Class I, Division 1 or Division 2 (Group C and D) environments, and the DM2 Explosion Proof safely exhausts actuator circuits during emergency shutdown events.
Gas compressor station pneumatic controls in classified areas where safe exhaust of actuator circuits is required before maintenance access, with the explosion-proof coils preventing ignition of any residual gas atmosphere.
Offshore platform pneumatic safety systems where the valve's Category 4, SIL 3 ratings meet the functional safety requirements of API and IEC 61511 process safety management standards in hydrocarbon-rich environments.

Chemical and Petrochemical Processing

Chemical reactor feed and product valve actuator circuits in NEC Class I hazardous areas where the DM2 Explosion Proof provides safe pneumatic energy removal during planned shutdowns, emergency stops, and maintenance lockout procedures.
Solvent and flammable liquid handling systems requiring Category 4 safe exhaust with explosion-proof actuation for actuators on filling, transfer, and dispensing equipment in classified areas.
Petrochemical refinery pneumatic valve actuator controls in areas classified for flammable vapors, where the DM2 Explosion Proof fulfills both the explosion protection and functional safety requirements in a single valve assembly.

Paint and Coating Application

Automotive and industrial spray painting booths classified as NEC Class I, Division 1 environments due to flammable solvent vapors, where pneumatic actuators for spray gun positioning, booth door controls, and conveyor drives require explosion-proof safe exhaust valves.
Powder coating operations in areas with combustible dust (NEC Class II) where the explosion-proof coil design prevents dust ignition from solenoid actuation during safe exhaust events.
Paint mixing and dispensing equipment in classified areas where the DM2 Explosion Proof provides Category 4 safe exhaust for pneumatic agitator and pump circuits.

Grain, Feed, and Agricultural Processing

Grain elevator and grain processing facilities with combustible grain dust environments (NEC Class II, Group G) where pneumatic conveying, gate, and valve actuators require explosion-proof safe exhaust valves for energy isolation during maintenance.
Feed mill pneumatic system controls in classified areas where the DM2 Explosion Proof enables Category 4 safe exhaust documentation for OSHA PSM and RMP compliance programs covering combustible dust hazards.
Corn, soybean, and wheat processing facilities where explosion-proof pneumatic safety valves are specified by insurance carriers and facility safety engineering standards for classified dust environments.

Mining and Mineral Processing

Underground mine pneumatic controls in methane-classified areas (NEC Class I) where safe exhaust of pneumatic drill and conveyor actuators is required before maintenance access and where explosion-proof actuation is mandatory.
Surface mine crushing and screening operations in NEC Class II combustible dust environments where the DM2 Explosion Proof provides safe pneumatic energy isolation for vibrator, gate, and chute actuators.

Pharmaceutical and Specialty Chemical Manufacturing

Pharmaceutical solvent handling and reactor operations in classified areas where Category 4 safe exhaust with explosion-proof actuation supports both process safety management and FDA equipment safety validation requirements.
Specialty chemical blending operations with flammable solvent or reactive gas atmospheres where pneumatic actuator circuits require explosion-proof safe exhaust with Category 4, SIL 3 certification for process hazard analysis documentation.

Ordering and Model Number Configuration

The DM2 Series C Explosion Proof model number encodes valve type, configuration, thread type, body size, port sizes, and voltage. Example: DM2CNB42A21019 = DM2C Series, NPT thread, Basic Size 4, 1/2" ports, 24 VDC, explosion-proof coils (suffix 019). Contact ROSS Controls for the complete configurator.

DM2 Series C Explosion Proof Model Number Structure:

DM2C Series designation (DM2C = Category 4 Double Valve, Internal Monitoring, Solenoid Reset)

N/D Thread type (N = NPT)

B Revision/configuration code

42 Basic size and port size code (42 = Size 4, 1/2" ports)

A21 Voltage and electrical code (24 VDC)

019 Explosion-proof coil option code

Standard voltage: 24 VDC.

Solenoid connection: lead wires with conduit fitting. No DIN or M12 quick-disconnect connectors available on explosion-proof variants.

Feedback switch connection: EN 175301-803 Form A.

NPT thread standard on explosion-proof variants.

Hazardous location classification: verify the valve's rated classification against the area's NEC or ATEX classification before installation.

Operating pressure max: 120 psig (8.3 bar).

Certifications: DGUV, CE, EAC.

SISTEMA Library files downloadable at rosscontrols.com.

Contact ROSS Controls at (800) 438-7677 for full variant listing, explosion-proof ratings, and application engineering support for hazardous location installations.

Accessories

Hazardous Location Conduit Fittings

Explosion-proof conduit connectors and fittings for sealing electrical conduit entries at the solenoid coil housing, maintaining the explosion-proof integrity of the solenoid enclosure. Must be installed per applicable NEC and local electrical code requirements.

Upstream Lockout L-O-X Valves

Manual lockout valves for upstream pneumatic energy isolation, enabling complete lockout/tagout compliance when used with the DM2 Explosion Proof safe exhaust valve. Select lockout valve materials and construction compatible with the hazardous area environment.

Explosion-Proof FRL Units

Filtered-regulated air preparation equipment rated for installation in classified areas, providing clean, regulated supply air to the DM2 Explosion Proof valve.

Pressure Gauges (Hazardous Location Rated)

Pressure gauges rated for use in classified areas for downstream pressure monitoring and system commissioning without introducing ignition sources.

Frequently Asked Questions (FAQ)

Q: What makes the DM2 Series C Explosion Proof different from the standard DM2C?

A: The DM2 Series C Explosion Proof uses specially designed explosion-proof solenoid coils that contain any spark or arc originating within the coil or housing, preventing ignition of flammable or explosive materials in the surrounding atmosphere. The solenoid connections use conduit wiring rather than DIN or M12 quick-disconnect connectors to maintain the sealed explosion-proof enclosure. The functional safety performance (Category 4, PL e, SIL 3, internal monitoring, solenoid reset) is identical to the standard DM2C Series.

Q: What hazardous location classifications is this valve rated for?

A: The DM2 Series C Explosion Proof is designed for use in NEC Class I (flammable gases and vapors) and NEC Class II (combustible dust) classified areas. Specific Division and Group ratings depend on the variant and must be verified with the product documentation and hazardous area classification for the installation site. Contact ROSS Controls for the specific hazardous location ratings applicable to your installation.

Q: How does the reset mechanism work in the explosion-proof version?

A: Identical to the standard DM2C: reset is accomplished exclusively by an electrical signal to the solenoid reset. The valve cannot be reset by removing and re-applying supply pressure. In a hazardous location, the reset signal wiring must be run through explosion-proof conduit and fittings maintaining the integrity of the electrical classification.

Q: What is the residual outlet pressure in the fault/latched condition?

A: Less than 1 percent of supply pressure, same as the standard DM2C Series. This near-complete pressure removal ensures the protected pneumatic circuit is effectively de-energized when the valve is latched in the safe state following a detected fault.

Q: What safety performance does this valve achieve?

A: Category 4, Performance Level e (PL e) per ISO 13849-1:2015, SIL 3 per IEC 62061, and DGUV functional safety certification. These ratings are identical to the standard DM2C Series and confirm suitability for the highest-severity pneumatic safety applications in hazardous locations.

Q: Can this valve be used in areas classified for both flammable gas and combustible dust?

A: The explosion-proof coil design is intended to address both flammable gas/vapor (Class I) and combustible dust (Class II) classified environments. The specific approval groups and divisions for a given variant must be confirmed with ROSS Controls and verified against the site area classification before installation.

Q: What conduit fitting is required?

A: Explosion-proof conduit fittings and sealing fittings (sealing compounds) are required at all conduit entries to the solenoid coil housing, per NEC Article 501 (Class I) and 502 (Class II) requirements. The specific conduit thread size and fitting type depend on the installation wiring method. Consult with a licensed electrical engineer for hazardous location installation.

Q: What is the maximum operating pressure?

A: 120 psig (8.3 bar), same as the standard DM2C Series.

Q: What certifications does this valve carry?

A: DGUV functional safety certification, CE marking, and EAC declaration. Explosion-proof ratings per applicable North American and/or international standards are confirmed with the specific variant documentation. SISTEMA Library files are available for ISO 13849-1 documentation.

Q: How does the feedback switch report valve status?

A: A mechanical pressure switch with both NO and NC contacts reports two states: ready-to-run (normal operation) and locked-out (fault/latched condition). The feedback switch uses an EN 175301-803 Form A connection. The wiring for the feedback switch must also comply with the hazardous location electrical requirements for the classified area.

Q: Is a SISTEMA Library available for this valve?

A: Yes. A downloadable SISTEMA Library file is available at rosscontrols.com, containing the required safety parameters (Category, PL, SIL, PFHD, B10D, MTTFD) for ISO 13849-1 safety function documentation.

Q: Can the DM2 Explosion Proof replace a standard DM2C in a non-classified area?

A: Yes, technically the explosion-proof variant will function in any area, classified or not. However, the standard DM2C is typically specified for non-classified environments because it offers DIN and M12 quick-disconnect connectors for faster installation and maintenance, lower cost, and a broader range of accessories. Reserve the explosion-proof variant for classified location requirements.

Installation & Maintenance Guidelines

Verify the area classification (NEC Class, Division, Group) before ordering. Confirm the valve's explosion-proof ratings match or exceed the area classification.
Install the base assembly and connect all field piping before installing the valve body.
All electrical conduit and wiring must comply with NEC Article 501 (Class I) or 502 (Class II) requirements, including the use of explosion-proof fittings, sealing fittings with sealing compound, and approved conduit types.
Install sealing fittings within 18 inches of the solenoid enclosure entry as required by NEC Article 501.15.
Wire both operating solenoid leads to the machine safety controller. Wire the solenoid reset leads to a separate controller output dedicated to the reset function.
Wire the mechanical pressure switch (NO and NC) to the safety controller input. All wiring must run in explosion-proof conduit.
Program the controller to prevent machine restart if the locked-out state is indicated by the feedback switch, and to require the deliberate solenoid reset sequence after fault investigation.
Supply filtered compressed air. 5-micron upstream filtration recommended. Max operating pressure: 120 psig (8.3 bar).
Perform commissioning functional test including fault simulation to verify: (a) valve latches in safe state and pressure switch reports locked-out; (b) pressure cycling does not reset; (c) solenoid reset restores ready-to-run.
Document all commissioning results, hazardous location compliance verification, and SISTEMA calculations in the machine technical file and process hazard analysis documentation.

Warranty & Global Support

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

Technical support: 1-888-TEK-ROSS (1-888-835-7677). Customer service: 1-800-GET-ROSS (1-800-438-7677).

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

SISTEMA Library files, dimensional drawings, CAD models, and certifications available at rosscontrols.com.

For hazardous location application engineering support and explosion-proof rating verification, contact ROSS Controls at (800) 438-7677.

Download Catalog: https://www.rosscontrols.com/en/series/1308-dm2-series-c-safe-exhaust-valve-explosion-proof