How to Build a Custom Domin Servo Valve
Configuring a Hydraulic Servo Valve from Scratch
It’s easy to build a hydraulic Domin Servo Valve using our guide down below. For retrofit applications, view our Domin Upgrades for popular Moog, Atos, Woodward, Star, Parker, Bosch Rexroth replacements.
Select a Domin Valve series and model before getting started
Before building your code, you should have a series and model selected. Our model selector guide, breaks down our most popular units by application requirement.
Currently, Domin offers two hydraulic valve lines, the S Series, designed for the servo valve market and the P Series, designed for the servo proportional valve market.
The S Series is popular for precise and dynamic applications, such as testing and simulation with incredibly fast response rates (<3.5 ms for NG06). For applications that focus on robustness and long-term consistency and less on bandwidth, the P Series offers a more affordable alternative.
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1. Define max flow rate
After selecting the valve series and model, choose your flow rate. The flow range is between 0.2-66 gpm (0.5-250 lpm), all rated at a 1,015 psi (70 bar) pressure drop. For systems requiring high precision control, the flow rate can be tuned to the nearest decimal point within the range to closely match your needs.
In the example below, “5” represents 1.32 gpm (5 lpm) for 35 bar ΔP Per Control Edge.
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2. Choose a spool lap condition
The spool lap condition determines how the valve reacts to control inputs. Two valves can share the same rated flow, response time, and flow curve, but one can hold the load still, while the other lets it drift.
The most popular spool lap condition is axis cut, also known as zero overlap. Other options include deadband, float center, overlap, etc. Overlap options allow you to fine tune the valve’s control characteristics and range from 3-10% depending on the desired smoothness and responsiveness.
Be sure to check the specific model data sheet to see what options are available, as the spool lap condition and letter representation vary across the model.
Here “F” represents Float Center.
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3. Select control input
Domin valves feature electrical feedback and onboard electronics to simplify integration into modern hydraulic systems. Power runs on standard 24V power supply and a typical input/output interface. Popular control options include ± 10 V and 4 to 20 mA, as these are standard for industrial automation processes.
Domin valves control options include ± 10 V, ± 20 mA, 4 to 20 mA, ± 5 mA, ± 10 mA, ± 50 mA, ± 40 mA, and ± 25 mA. You can also inquire for a specialized control input as needed.
In the example below, “C” represents 4 to 20 mA.
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4. Choose the power off position
When electrical power is removed, or the valve’s drive is disabled, the valve commands its internal spool to the centered/null position by default. Special inquiries can be made for alternate power off options.
In the example below, “C” represents Center.
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5. Select an electrical connector
Next, select the right electrical connector. Industry-standard connectors are provided to ensure easy compatibility and simple integration with your existing infrastructure.
The two most common connectors are the 4-pin hard-mounted connectors and 6-pin plus PE connectors. Depending on the valve series and configuration, additional connections may be available, including a flying lead (4 wires) and G4-20P rack-and-panel connector.
In the example below, “E” represents a 6 Pin + PE Circular Connector.
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6. Configure an enable mode
At this step, you will determine whether your system will have an enable mode or not. Some systems require this signal, which is essentially a simple yes or no option. This feature offers a second layer of control, allowing operators to manage when the valve is active to monitor safety.
In the example below, “N” represents No Enable Functionality
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7. Select a hydraulic fluid
By default, Domin valves use standard red oil, since this is used widely for modern hydraulic systems. If your application requires specialized fluid, we can work with you to design a custom solution for your operating conditions.
In the example below, “R” represents Recommended Oil.
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8. Determine the correct seal material
Seal material is an important part of any hydraulic component as it affects how well the valve holds up in your application. Common options include the following:
In the example below, “V” represents Viton.
S6 Pro-5-F-C-C-E-N-R-V
Explore Domin Retrofit Valves
Looking to replace an existing servo valve? Explore our Domin Upgrades for replacements for popular Moog, Atos, Woodward, Star, Parker, and Bosch Rexroth valve applications.