DM2® Series E Control Reliable Double Valves – Installation Instructions (Discontinued)

Overview

The ROSS Controls® DM2® Series E is a control-reliable double valve with dynamic monitoring and memory for Category 3 and 4 applications, except press clutch/brake use. Both pilot solenoids must be energized simultaneously to supply air from inlet port 1 to outlet port 2. If the two internal valve elements do not shift synchronously within the preset discordance time, the valve enters a lockout condition – exhausting downstream pressure through port 3 with an audible air flow.

A critical feature of the DM2® Series E is the memory function: once a lockout occurs, the valve remains locked out even after pilot solenoid power is removed. To return to ready-to-run state, the dedicated reset solenoid must be momentarily energized (at least 200 ms) with both main pilot solenoids de-energized and supply pressure applied. This anti-tie-down reset requirement prevents unintended pressure output upon reset.

Note: DM2® Series E valves are discontinued. Consult ROSS Controls at 1-800-GET-ROSS or visit www.rosscontrols.com for replacement product recommendations.

Key Features

Dynamic Monitoring with Memory for Category 4

The DM2® Series E monitors valve element synchronization during every actuation and de-actuation cycle. The memory function records any lockout and holds the valve in the locked-out state until a deliberate reset action is performed. No fault can be automatically masked by power cycling or transient conditions – every lockout requires an overt reset by a qualified person, making the DM2® Series E suitable for Category 4 applications.

Dedicated Reset Solenoid with Anti-Tie-Down Protection

The DM2® Series E includes a 3/2 normally closed reset solenoid (solenoid c). Reset requires: supply pressure applied, both main pilot solenoids de-energized, and a momentary signal (at least 200 ms) to the reset solenoid. After reset, allow at least 200 ms before applying power to the main solenoids.

Built-In Status Indicator Pressure Switch

The DM2® Series E includes a built-in status indicator pressure switch. During normal operation the switch is pressurized (contacts 1 and 3 closed – normally open). Lockout depressurizes the switch (contacts 1 and 2 closed – normally closed) until the valve is reset. Contact 4 is ground. This enables integration with machine control systems for automated lockout detection.

Technical Specifications

The following specifications are drawn from the official ROSS Controls DM2® Series E Installation Instructions (Doc ID 171):

Valve Type: Control-reliable double valve with dynamic monitoring and memory
Safety Category: Category 3 and 4 per EN ISO 13849-1
Reset Type: Memory/manual reset via dedicated reset solenoid
Reset Solenoid Type: 3/2 normally closed solenoid valve
Reset Signal: Momentary, at least 200 ms; both main solenoids must be de-energized
Reset Precondition: Supply pressure present; both main solenoids de-energized
Basic Size: 2
Status Indicator: Built-in pressure switch (4 contacts, Contact 4 is ground)
Recommended Filter: 5-micron-rated at valve inlet
Not for press clutch/brake applications
Discontinued – consult ROSS for replacement

Applications

Category 4 Safety-Critical Pneumatic Control

The DM2® Series E is designed for safety-rated applications requiring Category 4 performance. The memory function ensures no fault can be silently cleared. Typical Category 4 applications include guarded robot work cells, CNC machine tool interlocks, and other machinery where any pneumatic safety circuit fault must be definitively recorded and cleared before production can resume.

Large-Volume Pneumatic Systems and Reset Considerations

When commissioning DM2® Series E valves in systems with large downstream volumes, ensure full plant pressure and volume are applied during testing and reset. Insufficient supply pressure or volume can prevent successful reset. Quick connects or small hoses used during initial testing may provide insufficient flow for reliable reset operation.

Safety and Compliance Standards

DM2® Series E valves are designed for Category 3 and 4 applications per EN ISO 13849-1, except press clutch/brake applications. After installation or repair and before normal use, the valve must be tested following the DM2® Series E test procedure. Common reset failure causes: main solenoids still energized (safety feature), insufficient supply pressure/volume, supply pressure removed before de-energizing valve (both elements in faulted state), or reset solenoid mounted backwards.

Installation and Setup Guide

DM2® Series E Test and Reset Procedure

Before testing, reset: apply supply pressure, de-energize both main pilots, momentarily energize reset solenoid (≥200 ms). (A) Energize both solenoids simultaneously – port 2 pressurized, no flow to port 3. (B) De-energize one solenoid – lockout: port 2 exhausts to port 3. (C) Re-energize de-energized solenoid – valve must remain in lockout. (D) De-energize both solenoids – valve must remain in lockout (memory function). (E) Reset: momentarily energize reset solenoid (≥200 ms) – valve returns to ready-to-run. (F-J) Repeat with the other solenoid.

Reset Troubleshooting

If the DM2® Series E will not reset: verify both main solenoids are de-energized; verify full supply pressure and volume; verify reset solenoid is correctly oriented (air should not exit from the stem nut when energized); if supply was removed before de-energizing, both elements may be in faulted state. Contact ROSS Technical Services for additional support.

Why Choose ROSS Controls

ROSS Controls has been a leader in control-reliable double valve technology for decades. The DM2® Series E memory function and dedicated reset requirement represent best-practice design for Category 4 safety circuits. For current replacement products, contact ROSS at 1-800-GET-ROSS or visit www.rosscontrols.com.

Download This Document

The official ROSS Controls DM2® Series E Control Reliable Double Valves Installation Instructions (Doc ID 171) can be downloaded from the ROSS Controls document library.

PDF Download URL: https://ross-admin-global-us-east.s3.amazonaws.com/production/uploads/document_language_file/file/171/ROSS_DM2_Series_E_Control_Reliable_Double_Valves_SS303.pdf

Frequently Asked Questions

Q: Why does the DM2® Series E require a manual reset after lockout?

A: The memory function ensures a lockout is not silently cleared by removing power. This is required for Category 4 applications where every safety circuit fault must be explicitly acknowledged and cleared by a qualified person before production can resume.

Q: How long must the reset signal be applied?

A: The reset solenoid must be energized for at least 200 milliseconds. After removing power from the reset solenoid, allow at least 200 ms before applying power to the main pilot solenoids.

Q: What are the preconditions for a successful DM2® Series E reset?

A: Supply pressure must be present; both main pilot solenoids must be de-energized; the reset solenoid must be correctly oriented; and the supply must provide sufficient pressure and volume.

Q: Can the DM2® Series E be used for press clutch/brake applications?

A: No. Due to its air flow and exhaust characteristics, the DM2® Series E is not suitable for press clutch/brake applications. Use the DM2® Series D specifically designed for that purpose.

Q: What does the built-in status indicator do?

A: The built-in status indicator pressure switch changes state when a lockout occurs (contacts 1 and 2 close, contacts 1 and 3 open). This signal connects to the machine control system to halt operation and alert maintenance personnel.

Q: Is the DM2® Series E still available?

A: DM2® Series E valves are discontinued. Contact ROSS Controls at 1-800-GET-ROSS or www.rosscontrols.com for current replacement product options.

Q: What happens if the reset solenoid is mounted backwards?

A: If mounted backwards, energizing the reset solenoid causes air to exit from the exhaust port in the nut on the solenoid stem, and no reset action occurs. If the reset solenoid exhausts air when energized and does not reset the valve, check the solenoid orientation.

Q: What is the discordance time on the DM2® Series E?

A: The discordance time is the preset maximum allowed time difference between the two valve elements shifting. If one element does not shift within this time window relative to the other, the valve enters lockout. Consult ROSS for detailed timing data.