DM Series C Valves Operating Instructions — DM1 and DM2® Series C

Overview

The ROSS Controls DM1 Series C and DM2® Series C are electropneumatic double valves designed for control-reliable Category 3 and Category 4 safety applications. These valves combine two independent valve elements in a single housing, providing redundant monitoring and — in the case of DM2® Series C — inherent lockout capability with manual reset.

Published as operating instructions document RC-DMC-OI, this multilingual guide covers both the DM1 and DM2® Series C across all available basic sizes (BG 2, 4, 8, 12, 30). The document is available in English, German, French, Italian, Spanish, and Swedish, reflecting ROSS Controls' global manufacturing and service presence. The DM Series holds DGUV certification (HSM 06008) and a Declaration of CE Conformity.

ROSS Controls, founded in 1921, brings over 100 years of fluid power expertise to every valve design. U.S. patents 6840258 and 6840259 — along with further patents filed worldwide — protect the unique cross-monitoring technology in the DM Series double valves.

Key Features

Category 4 PL e / SIL 3 — Highest Machine Safety Ratings

Both DM1 Series C and DM2® Series C are certified to Category 4, Performance Level e per ISO 13849-1:2015 and SIL 3 per IEC 62061:2001. This certification is backed by DGUV approval (HSM 06008) and a full Declaration of CE Conformity, satisfying the most stringent requirements for machine safeguarding in manufacturing environments worldwide.

Patented Cross-Monitoring Technology

The cross-monitoring design (U.S. Patents 6840258 / 6840259) uses the position of each valve element to monitor the other. If either element fails to shift within the preset discordance window, the valve detects the fault and takes safe action. In DM2® Series C, this results in a locked-out state requiring intentional reset; in DM1 Series C, an automatic reset is possible once the fault clears.

Wide Range of Basic Sizes: BG 2 Through BG 30

The DM Series C is available in five basic sizes — BG 2, BG 4, BG 8, BG 12, and BG 30 — to accommodate a broad range of flow requirements and machine sizes. Dimensional data from the official operating instructions specifies exact envelope dimensions for each size, facilitating system design and installation planning.

Technical Specifications

Specifications are taken directly from the DM Series C operating instructions (RC-DMC-OI):

Performance Level: Category 4, PL e per ISO 13849-1:2015
Safety Integrity Level: SIL 3 per IEC 62061:2001
Certifications: DGUV HSM 06008; Declaration of CE Conformity
Patents: U.S. Patent Nos. 6840258, 6840259; further patents filed worldwide
Basic Sizes Available: BG 2, BG 4, BG 8 (DM1 C); BG 2, BG 4, BG 8, BG 12, BG 30 (DM2® C)
Valve Type: Electropneumatic double valve (3/2 normally closed function overall)
Actuation: Dual solenoid pilots (both must be energized simultaneously for normal operation)
DM1 C Reset: Automatic reset when fault condition clears (de-energize both solenoids)
DM2® C Reset: Inherent lockout with intentional reset required via dedicated reset solenoid
Discordance Detection Time: Approximately 125 milliseconds
Electrical Connection: Plug-in connectors (solenoid power)
Solenoid Power: Standard voltages 24 VDC; 110–120 VAC, 50/60 Hz
Flow Media: Filtered compressed air
Mounting: Base mounting

Applications

Category 3 and 4 Machine Safety Systems

The DM Series C double valves are intended for use in Category 3 and Category 4 safety applications as defined by ISO 13849-1. Typical installations include pneumatic clamping systems, material handling presses, assembly automation, and any pneumatically powered machine where redundant, monitoring valve control is required by a risk assessment. These valves are specifically NOT for press clutch/brake applications — the DM2® Series D is designed for those uses.

Global Industrial Applications

With multilingual operating instructions (EN/DE/FR/IT/ES/SV) and a full Declaration of CE Conformity, the DM Series C is specified by machine builders across North America, Europe, and worldwide. ROSS's global offices and distributor network in Germany, Japan, UK, Brazil, India, China, France, and Canada ensure local support wherever the valve is installed.

Safety and Compliance Standards

ISO 13849-1:2015 — Safety of Machinery: Safety-related parts of control systems
IEC 62061:2001 — Functional safety: SIL assessment
DGUV Certification: HSM 06008 (Sicherheit geprüft / tested safety)
CE Declaration of Conformity — available at www.rosscontrols.com
Not intended for press clutch/brake control (see DM2® Series D for press applications)

Installation and Setup Guide

Air Line and Filter Preparation

Before installation, blow all air lines clean of contaminants. Install a 5-micron rated air filter in the inlet line close to the valve. Ensure the filter bowl is regularly drained; install an automatic drain if the location makes manual draining difficult.

Port and Pipe Connections

The DM Series C is base-mounted. Install piping into base ports by engaging pipe one turn, applying thread sealant (tape not recommended), then tightening. For parallel threads (SAE, ISO 228-G), do not use sealant. After piping the base, blow compressed air through lines to clear debris, then install the valve onto the base. Ensure Port 1 (inlet) supply line is of adequate size without restrictions.

Electrical Supply and Reset Solenoid

Match the electrical supply to the solenoid voltage and frequency ratings. DM2® Series C double valves include a 3/2 normally closed reset solenoid; the reset signal must be momentary and at the correct voltage. Both main pilot solenoids must be de-energized before reset can occur — this anti-tie-down feature prevents unintended pressure output on reset. Allow at least 200 ms delay between removing reset power and applying main solenoid power.

Testing After Installation

After installation, test the lockout function: (A) Energize both solenoids simultaneously, then de-energize one — the valve should lock out. (B) Energize both solenoids — the valve should remain locked out. (C) De-energize both solenoids and reset. (D) Repeat test with the other solenoid. Only after passing all tests is normal operation permitted.

Why Choose ROSS Controls

ROSS Controls has manufactured pneumatic safety valves since 1921. The DM Series represents over decades of continuous development of double valve technology, from the original SERPAR® design through the current patented cross-monitoring architecture. Every DM Series C valve is assembled, tested, and certified to meet the most demanding international safety standards.

Call 1-800-GET-ROSS or visit www.rosscontrols.com to speak with an application engineer, locate your nearest ROSS distributor, or download complete technical documentation including declarations of conformity.

Download This Document

The official DM Series C Operating Instructions document (RC-DMC-OI) covers both DM1 Series C and DM2® Series C in English, German, French, Italian, Spanish, and Swedish. It includes dimensional drawings for all BG sizes, wiring diagrams, operation timing charts, and complete test procedures.

Download PDF: https://ross-admin-global-us-east.s3.amazonaws.com/production/uploads/document_language_file/file/213/ROSS_DM_Series_C_Double_Valves_Operating_Instructions_RC-DMC-OI.pdf

Frequently Asked Questions

Q: What is the difference between DM1 Series C and DM2® Series C?

A: DM1 Series C uses automatic reset — the valve returns to ready-to-run state once the fault clears and both solenoids are de-energized. DM2® Series C uses inherent lockout with memory — once locked out, an intentional reset signal is required to resume operation. DM2® Series C is recommended where undetected momentary lockouts must be prevented.

Q: Are DM Series C valves suitable for press clutch/brake applications?

A: No. DM Series C valves are expressly not intended for press clutch/brake applications. ROSS Controls produces the DM2® Series D specifically for mechanical power press clutch/brake control.

Q: What basic sizes are available for the DM2® Series C?

A: DM2® Series C is available in BG 2, BG 4, BG 8, BG 12, and BG 30. DM1 Series C is available in BG 2, BG 4, and BG 8.

Q: How long is the discordance detection window?

A: The internal monitoring system locks out the valve if the time difference between both valve elements shifting fully is longer than approximately 125 milliseconds. This timing is preset by restricting orifices and chambers in the pilot air circuit.

Q: What does the anti-tie-down feature do?

A: The anti-tie-down feature requires both main valve solenoids to be de-energized before the reset signal is accepted. This prevents a reset from inadvertently pressurizing the outlet while solenoids are still energized.

Q: What voltage options are available for DM Series C solenoids?

A: Standard voltages are 24 VDC and 110–120 VAC at 50/60 Hz. The electrical supply must correspond to the solenoid ratings to avoid early solenoid failure.

Q: What safety standards does the DM Series C comply with?

A: The DM Series C complies with ISO 13849-1:2015 (Category 4, PL e), IEC 62061:2001 (SIL 3), and holds DGUV Certification HSM 06008 along with a full Declaration of CE Conformity.

Q: Where can I download the DM Series C Declaration of Conformity?

A: Declarations of CE Conformity and certifications for the DM Series C are available for free download at www.rosscontrols.com.