Custom Hydraulic Control Valve Assemblies


The 33.6 kg (74 lb.) hydraulic control valve assembly pictured controls the pressure, flow, and direction of fluid in a hydraulic system. It is used within 20 to 30 ton excavator-type construction machines.

Tuson faced many challenges during the course of this project. The design tolerances were extremely precise; some required an accuracy of 1 micron (.001 mm or 0.00004 inches). The main bore of this valve assembly is 269 mm (10.59 inches) long, has an O.D. requirement of 28.000 ± 0.0015 mm (1.10236 ± 0.00006 inches), a roundness tolerance of .003 mm (0.0001 inches), and a cylindricity tolerance of .005 mm (0.0002 inches)!!!

However, not only does the valve body have tight tolerances, the components within the valve assembly also do. For example, the main spool has roundness and straightness tolerances of 2 and 3 microns (0.00008 and 0.0001 inches) respectively, with outside diameter tolerances of ± 1.3 microns (± 0.00005 inches). In addition, the main spool design contains three different diameter sizes. This feature required Tuson to develop a custom (special) final grinding process for production.

To meet these tight tolerances, Tuson invested in new, state-of-the-art capital equipment. We also created a “clean room” environment with constant temperature for the valve final assembly and test area.

Tuson is proud of its accomplishments associated with this project. They are examples of some of the steps we take as a supplier in producing precision-machined components, assemblies, and systems to meet the needs of the world’s top equipment and machinery OEMs. In addition, we offer customers cost-effective Pacific Rim sourcing and manufacturing, combined with North American inventory, sales, service, and support.

We can help make your next project a success. Please give us a call, or submit a request for quote online today. We stand ready to be of service!

Hydraulic control valve


Project Name:

Custom Hydraulic Control Valve Assemblies

Project Description:

Cast Valve Assembly to Control Pressure, Flow, and Direction of Hydraulic Fluid in 20-30 Ton Excavators

Capabilities Applied/Processes:

  • Casting Sourcing and Procurement
  • Precision Machining of Several Materials
  • Precision Honing
  • Precision Turning
  • Precision Grinding
  • Heat Treatment
  • The Design and Fabrication of Custom Assembly Fixtures for Special Methods
  • Product Assembly
  • Complete Function and Leak Testing

Equipment Used to Manufacture Part:

Various CNC and Other

Basic Dimensions:

L x W x H: 395 x 352 x 90 mm (15.6 x 13.9 x 3.5 inches)

Tightest Tolerance Held:

0.002 mm (0.0001 inch) Roundness

Materials Used:

Ductile Iron, Carbon Steels, and Others

Industry for Use:

Construction Machinery and Equipment

Production Volume:

To Meet Customer Needs