Check/Relief Valves

LDI is your source for made-to-order direct operated check valves and relief valves. These style valves allow for free flow in one direction only. Whether being used to control movement or speed of movement within the hydraulic system or to protect valuable components within the hydraulic system from damage, LDI will design and manufacture reliability and performance into the valve.

Direct operated valves open or crack at defined pressures established through the preload exerted on the valve poppet by a spring. Crack pressure requirements vary by application and LDI will customize the valve design to satisfy these requirements.

Many check valves and relief valves we produce are incorporated into fittings configured for assembly directly into hydraulic systems. As a general guideline, consider the topics below with reference to your application prior to submitting a RFQ.

  • Valve function - check or relief
  • System fluid specifications
  • Operating Conditions
    • Maximum & normal operating pressure
    • Maximum & normal operating temperature
  • Performance Requirements
    • Crack or relief pressure
    • Maximum & normal flowrates expected through valve
    • Limits on pressure drop across valve at specific flow rates
    • Leakage limits across valve seat
  • Valve Body Requirements
    • Body geometry and connections
    • Valve location
    • Physical size limitations
    • Material
    • Finish or corrosion resistance level
  • Sales Information
    • Packaging requirements
    • Annual usage forecast and release quantities
    • Development and production schedules

Need assistance? Contact our experienced technical Staff to discuss the application and options offered by LDI to meet your performance targets.


View some of our Check/Relief Valves.

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Check-Relief Valves




LDI - Corporate  Click for map LDI   Click for map
Precision Machining & Assembly Fabrication & Assembly
1864 Nagle Ave. 12901 Jim Dhamer Dr.
Manitowoc, WI  54220 Huntley, IL  60142
PH: 920.682.6877                         
FAX: 920.684.7210                                    



Our talented team of degreed and professionally certified Engineers, Quality Assurance, Production and Customer Service staff have many years of experience in the industry.  Their attention to detail and ability to collaborate with our clients to solve their problems is reflected in the 50+ years we have been in business.


Customer Service: 

920.682.6877, option 4

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