Electro-Proportional Hydraulic Valves


The first electro-proportional hydraulic valve assembly to be completely manufactured by Tuson was this solenoid-operated hydraulic valve. The successful launch of this valve has helped us to design and manufacture several other fully assembled valves possessing similar or greater complexity and precision.

The project presented several challenges that we met and overcame. First, the critical tolerances were very tight. There were multiple tolerances of +/- 0.005 mm (+/- 5 microns, or +/- 0.0002 inches). There were also multi-step holes with varying inside diameters (I.D.s). These made the valve difficult to machine at first. However, with on-going improvements to our machining processes, we were able to meet or exceed all the tolerances and consistently hold them during series production.

Also, the valve proved to be difficult to test. However, with the collaboration and help of our customer, we were able to design and fabricate a custom test stand that consistently provided us with accurate test results.

Finally, another aspect of this project was the need for a clean room for assembly due to strict contamination requirements. Therefore, we made a significant investment and had an ISO Class 8 clean room constructed within our facilities.

Overall, this project took about 2.5 years to go from concept phase all the way through to series production. We are very proud of our success with this project. It was an important milestone for us, and marked the beginning of a very good relationship with an important OEM customer. It also served as the basis for several future projects that were similar.

Tuson has over 30 years of experience in producing high quality, precision-machined custom components, assemblies, and systems. We also offer economical Pacific-Rim sourcing and manufacturing locations, combined with North American inventory, and sales, service, and support.

Please call us, or submit a request for quote online today.  We’d like to hear about your needs, and help make your next project a success.


Project Name:

Electro-Proportional Hydraulic Valve Manufacturing

Project Description:

The Manufacturing, Assembly, and Testing of Electro-Proportional Hydraulic Valves

Capabilities & Processes Applied:

  • Aluminum Casting Design, Sourcing, and Procurement
  • Precision Machining of Several Materials
  • Clean Room Constructed for Product Assembly
  • Particle Counter Used for Hydraulic Fluid Contamination Monitoring
  • Production Test Stand Design and Fabrication
  • Product Assembly
  • Full Function and Leak Testing

Equipment Used to Manufacture Part:

Various CNC and Other

Basic Dimensions:

L x W x H = 173 x 59 x 74 mm (6.8 x 2.3 x 2.9 inches)

Tightest Tolerance Held:

+/- 0.005 mm (+/- 0.0002 inches)

Materials Used:

ADC14, PM Steel, 303 SS Steel, AA 7075 Aluminum, and Others

Industry for Use:

Construction Machinery and Equipment

Production Volume:

To Meet Customer Needs