DM2® Series D and Series F Electropneumatic Double Valves Operating Instructions (RC-DM-DF-OI)

Overview

The ROSS Controls DM2® Series D and DM2® Series F are electropneumatic double valves with dynamic monitoring and inherent lockout capability for Category 4 press clutch/brake control applications. These valves are specifically engineered to meet the demanding requirements of mechanical power press safety, providing the self-contained monitoring, redundant valve elements, and crossflow air passages required for Cat. 4, Performance Level e applications.

The DM2® Series D and F are available in Basic Sizes 2, 4, and 8, providing flow capacity for a wide range of press tonnage and air volume requirements. Both series use the same foundational DM2® design with dynamic monitoring, anti-tie-down reset, and inherent lockout that prevents further press cycling after a valve element discordance is detected. Certifications and Declaration of CE Conformity are available at www.rosscontrols.com.

These operating instructions (RC-DM-DF-OI) are published in nine languages (EN, DE, FR, IT, ES, RU, PT, JA, ZH), reflecting the global deployment of DM2® press safety valves across manufacturing facilities worldwide. ROSS Controls was founded in 1921 and has over 100 years of fluid power engineering expertise. For technical support, call 1-800-GET-ROSS.

Key Features

Self-Contained Dynamic Monitoring with Inherent Lockout

The DM2® Series D/F valve is completely self-contained — it does not require an external monitoring system. Dynamic monitoring continuously checks both valve elements for synchronous shifting. If either element fails to shift within approximately 125 milliseconds of the other, the internal monitoring system locks out the valve. Once locked out, the valve cannot be operated until deliberately reset, preventing unintended press strokes.

CrossFlow Passages for Fail-Safe Redundancy

Main airflow from Port 1 to Port 2 passes through crossflow passages between both main valve elements. Both elements must be fully shifted for Port 2 to be pressurized. This CrossFlow architecture provides a physical (not just electronic) layer of redundancy, ensuring that a single valve element failure cannot alone allow press clutch engagement.

Anti-Tie-Down Reset for Operator Safety

The DM2® Series D/F incorporates an anti-tie-down reset feature that requires both main solenoids to be de-energized before and during reset. This prevents an operator from holding the press run signal while simultaneously resetting the valve — a critical safety interlock for press room applications.

Dimensioned Drawing Data — Basic Sizes 2, 4, and 8

Dimensional data (inches/mm) from the operating instructions: Basic Size 2 — A: 4.79 (121.6); B: 4.50 (114.3); C: 10.89 (276.7); D: 7.90 (200.8). Basic Size 4 — A: 6.93 (176.0); B: 5.28 (134.1); C: 10.95 (278.1); D: 9.44 (239.8). Basic Size 8 — A: 8.73 (221.7); B: 5.94 (150.9); C: 12.73 (323.3); D: 11.16 (283.5). All measurements in inches with millimeter equivalents in parentheses.

Technical Specifications

Specifications from the DM2® Series D/F operating instructions (RC-DM-DF-OI):

Safety Category: Cat. 4, PL e per ISO 13849-1:2015
Safety Integrity Level: SIL 3 per IEC 62061
Valve Type: Electropneumatic double valve, base mounting
Basic Sizes Available: BG 2, BG 4, BG 8
Permissible Pressure Range: 2.1 to 8.3 bar (30 to 120 psig) — DM2® D; consult datasheet for DM2® F
Standard Voltage: 24 volts DC
Solenoid Cables: With EN connector, pinout: Brown PIN 1
Lockout Detection Timing: Approx. 125 ms discordance tolerance
Reset Type: Momentary air signal to RESET port, or optional solenoid reset
Reset Anti-Tie-Down: Both main solenoids must be de-energized during reset
Reset Duration: Momentary — 200 ms minimum recommended
Mounting: Base mounting
Certifications: U.S. Patent No. 6840258 / 6840259; Declaration of CE Conformity
Documentation Languages: EN, DE, FR, IT, ES, RU, PT, JA, ZH

Applications

Mechanical Power Press Clutch/Brake Control

The DM2® Series D is the premier ROSS product for mechanical power press clutch/brake control. The self-contained Cat. 4, PL e monitoring, lockout, and anti-tie-down features satisfy the most demanding press safety standards, including OSHA 29 CFR 1910.217, ANSI B11.1, and EN 692. The DM2® Series D is the appropriate choice for all mechanical power press applications — not the DM2® Series C, which is designed for non-press safety applications.

Stamping, Forming, and Forging Press Safety

Stamping, forming, and forging presses using air clutch/brake mechanisms require a Cat. 4 double valve with self-contained monitoring and lockout. The DM2® Series D meets these requirements in all three basic sizes, with sufficient flow capacity for presses ranging from small gap-frame to large heavy-tonnage applications.

Safety and Compliance Standards

ISO 13849-1:2015 — Category 4, PL e
IEC 62061 — SIL 3
OSHA 29 CFR 1910.217 — Mechanical power press safety
ANSI B11.1 — Mechanical power press safety
EN 692 — Mechanical power press safety (EU)
U.S. Patent No. 6840258 and 6840259 (additional patents worldwide)
Declaration of CE Conformity — available at www.rosscontrols.com

Installation and Setup Guide

Pre-Installation Checklist

Before installing: blow all air lines clean of contaminants; install a 5-micron-rated filter at the inlet; verify that the electrical supply voltage matches solenoid ratings; review the complete operating instructions; confirm reset port plumbing is in place.

Port Connections

Port 1 (Inlet): Supply line must be adequately sized and free of restrictions (crimps, sharp bends, clogged filter). Both pressure and volume must be adequate. Port 2 (Outlet): Locate the valve close to the press mechanism. Lines must be free of restrictions. Port 3 (Exhaust): Do not restrict exhaust — this adversely affects valve operation. Reset Port: If no reset solenoid is fitted, connect the RESET port externally to a 3/2 normally closed valve. Provide a momentary reset signal only.

Reset Timing Protocol

Per the DM2® Reset Timing Chart: (1) Anti-tie-down requires both main solenoids off during reset. (2) Reset duration should be momentary — 200 ms minimum. (3) After reset signal ends, allow 200 ms for pilot chambers to refill before energizing main solenoids. (4) Fault detection is constant. (5) Removing supply pressure while the valve is energized causes a fault and requires a reset.

Troubleshooting Reset Failures

Common reset failure causes: (1) Main solenoids are energized — both must be off. (2) Insufficient supply pressure to Port 1. (3) Both valve elements faulted due to supply pressure removed while energized — increases leakage on reapplication. (4) Reset solenoid mounted backwards — energizing the reset solenoid releases air through its exhaust port rather than performing a reset.

Why Choose ROSS Controls

ROSS Controls invented and patented the DM2® double valve technology (U.S. Patents 6840258/6840259). The DM2® Series D is the industry-standard press safety valve, deployed in stamping and forming facilities worldwide. Founded in 1921, ROSS Controls has over 100 years of expertise in fluid power and machine safety. Contact ROSS at 1-800-GET-ROSS or visit www.rosscontrols.com.

Download This Document

The official DM2® Series D and Series F Operating Instructions (RC-DM-DF-OI) are available as a free multilingual PDF download.

PDF Download URL: https://ross-admin-global-us-east.s3.amazonaws.com/production/uploads/document_language_file/file/169/ROSS_DM2_Series_D_Double_Valves_Operating_Instructions_RC-DM-DF-OI.pdf

Frequently Asked Questions

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

A: The DM2® Series D is specifically designed and certified for mechanical power press clutch/brake control applications (Cat. 4, PL e). The DM2® Series C is designed for Cat. 3 and 4 safety applications but expressly not for press clutch/brake applications. Always use the Series D for mechanical power press applications.

Q: Does the DM2® Series D require an external monitoring system?

A: No. The DM2® Series D is completely self-contained and does not require an external monitoring system. The internal dynamic monitoring continuously checks both valve elements for synchronous operation.

Q: What is the discordance detection time?

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

Q: Why does the anti-tie-down feature require solenoids to be off during reset?

A: This is a critical safety interlock that prevents an operator from holding the press run signal while simultaneously resetting the valve. If main solenoids were energized during reset, the press could cycle immediately upon reset completion, creating a hazardous condition.

Q: What happens if supply pressure is removed while the valve is energized?

A: Removing supply pressure while the valve is energized causes a fault condition. The valve must be reset before normal operation can resume. If both valve elements enter the faulted condition, leakage to the exhaust port will be greater when supply pressure is reapplied, potentially causing insufficient reset pressure issues.

Q: What are the available basic sizes for the DM2® Series D/F?

A: Basic Sizes 2 (BG 2), 4 (BG 4), and 8 (BG 8) are available. Higher Basic Size numbers indicate larger valve body and higher flow capacity.

Q: What voltage is standard for the DM2® Series D/F?

A: Standard voltage is 24 volts DC. Solenoid cables include EN connectors.

Q: Where can I download the Declaration of CE Conformity?

A: Declarations of CE Conformity and certifications for DM2® Series D/F valves are available for free download at www.rosscontrols.com.

Q: What is the recommended reset duration?

A: Reset duration should be momentary — a minimum of 200 ms is recommended. After the reset signal is removed, allow at least 200 ms for pilot chambers to refill before energizing the main valve solenoids.

Q: Are these operating instructions available in languages other than English?

A: Yes. The RC-DM-DF-OI document is published in nine languages: English (EN), German (DE), French (FR), Italian (IT), Spanish (ES), Russian (RU), Portuguese (PT), Japanese (JA), and Chinese Simplified (ZH).