DREHMO electric actuators for industrial valves

Identify the installed configuration

Start with a complete, readable actuator nameplate and an overall photograph of the installed assembly. Include the type, serial number and electrical information. The overall view connects these details to the control unit, output drive, valve connection and any separate gearbox in the assembly.

Copy all letters, numbers and suffixes without shortening the designation. For an electronic component, add its own label and connector photographs. An earlier technical specification can help establish the original configuration; record subsequent changes alongside it.

State whether the task is to preserve the existing arrangement or to change the control concept. This distinction determines whether the enquiry concerns a repair item, a complete replacement actuator or a new actuator package for the valve.

Define the equipment and spare-parts scope

List a complete actuator, a control module, a sensor, a motor and a mechanical component as separate enquiry items. Assign a quantity and drawing position to each. For a repair kit, attach the required contents and identify the actuator to which the kit belongs.

A complete actuator enquiry needs valve and motion requirements. A component enquiry needs the component’s own identification and its position within the assembly. When both are required, keep their rows linked to the same equipment reference.

This makes the supply scope reviewable by purchasing and maintenance staff. They can compare the requested item, existing designation and proposed package without treating an actuator, a valve or an individual module as the same deliverable.

Match the actuator to the valve

Provide an installation drawing or clear photographs of the flange, shaft and output coupling. For multi-turn equipment, include valve travel and stem details. For part-turn equipment, identify the shaft profile and required angle.

For a thrust assembly, specify the stroke, force and stem connection.

Record the available installation space and mounting arrangement. If a separate gearbox is installed, include its nameplate and assembly designation. Describe the mating component together with the actuator output connection.

For an upgrade, mark the components that will remain in service: valve, gearbox, support or adapter. The enquiry can then address the actual installation boundary and identify the connecting parts needed for the proposed assembly.

Specify electrical signals and communication

Use the current wiring diagram to describe motor power, control power, commands and feedback. For s-range, cabinet components form part of the installation’s external control arrangement.

For i-matic and x-matic, identify the integral control configuration from the installed unit and its documentation.

For a networked actuator, name the required interface: Profibus DP, Modbus RTU, Foundation Fieldbus H1 or HART. Include the communication module identification and the relevant network configuration. State the purpose of any analogue signal and identify the receiving controller.

When replacing electronics, provide the part number, hardware version and connector views. These details establish the information needed to compare the component with the wiring and operating requirements of the existing system.

Describe duty and installation conditions

Describe how the valve operates: full opening and closing, occasional positioning or frequent modulation. The i-matic documentation distinguishes these applications, including DiM and DiM R, and DPiM and DPiM R designations. State the actual service duty required by the plant.

Add the required torque or thrust, output speed or travel time, switching frequency and available load information. Record ambient temperature, indoor or outdoor location, moisture, vibration and exposure to the process environment.

For x-matic enquiries, provide the project requirements for the installation area and photographs of the relevant markings. Highlight changed process conditions separately so that the proposed equipment configuration is assessed against the intended service, including any new requirements.

Plan a replacement or control-system upgrade

When retaining the valve, compare the mechanical connection and operating duty first, followed by electrical power and controls. Moving from an external control cabinet to integral actuator controls affects the project’s commands, switching equipment, feedback and commissioning requirements.

For an existing c-matic or another earlier configuration, provide the complete type, wiring diagram and documentation for the installed assembly. Historical literature can help identify the original design.

State whether existing connections must be retained or whether the project allows their redesign.

Prepare the comparison around the individual devices and installation requirements. List the actuator, additional components and integration work within the agreed scope, keeping the current configuration and proposed changes clearly identifiable in the technical specification.

Prepare a repair or maintenance enquiry

Describe the observed problem: no movement, stopping at a particular position, torque indication, missing feedback or failure of local operation. Record when the issue occurs and the displayed messages. Include relevant operating-log entries when they are available.

Add recent changes such as an electronic module replacement, wiring work, valve maintenance or a revised operating duty. These details support the technical enquiry and identification of the required component. A damaged-part photograph should be linked to its assembly position.

Inspection and measurements on installed equipment belong to qualified personnel following the plant’s procedures. The procurement enquiry gathers the identification and technical evidence needed to discuss parts and repair scope for that particular assembly.

Prepare the project specification

For a new installation, provide the valve schedule, required motion, mounting interface, torque or thrust, travel time, duty and environmental conditions. Add power supply, control method and feedback requirements. A functional diagram helps show the actuator’s role within the overall system.

Give each procurement item a designation, quantity, unit and package contents. Name drawings and photographs using the same item references. Include the delivery destination and technical documents required for acceptance at the facility.

Keep a revision record when requirements change. The enquiry and subsequent offer should refer to the same agreed specification, allowing engineering, maintenance and purchasing staff to review a consistent equipment and spare-parts scope.

Applications and manufacturer background

DREHMO GmbH manufactures valve actuators in Wenden, Germany, and has belonged to the AUMA Group since 2008. Its documented application sectors include power generation, water and oil and gas. The application description helps establish the requirements of the particular valve installation.

For a power project, identify the water or steam circuit and the valve’s operating task. For a pipeline, tank-farm or water installation, describe the process function and control arrangement. Attach the relevant project specification alongside the actuator information.