In 1920, Tesla presented his patent for a fluid diodes, a pipe with no moving parts, which has the ability to leak fluid under pressure in one direction (Valvular Conduit No 1.329.559, dated February 3, 1920). The original Tesla valve consisted of a set of cavities and fluid-flow guides that allow flow with low resistance in one direction but result in a high resistance to flow in the opposite direction, hence building up a back pressure.

Back in the 60’s this device was used as a memoryelement of pneumatic computers. Tesla was honored for finding the principle. He considered the features of this device in particular when using high-frequency isochron fluid impulses.