Our full-color catalog can be mailed directly to you! Please click here to send us your request... your default email application will open and you can email us your catalog request. We will mail your catalog to you within one business day. Thank you! Made in the USA Pioneers in Fluid Power Established in 1912, Fulflo was incorporated in 1933 under its present name and trademark. Patents for the original guided piston, direct-acting relief valve were obtained in 1935, coincident with the onset of fluid power systems.

The need for providing large flows without excessive bulk was subsequently met by the pilot-valve-controlled relief valve, a patent on which was issued to Fulflo in 1943 (U.S. Patent No. 2,333,522).