A quick DDG [1] turned up this - <a href="http:&#x2F;&#x2F;hydraulicspneumatics.com&#x2F;200&#x2F;TechZone&#x2F;PneumaticValves&#x2F;Article&#x2F;False&#x2F;6455&#x2F;TechZone-PneumaticValves" rel="nofollow">http:&#x2F;&#x2F;hydraulicspneumatics.com&#x2F;200&#x2F;TechZone&#x2F;PneumaticValves...</a> which looks like the first chapter of an entire html book on the topic <a href="http:&#x2F;&#x2F;hydraulicspneumatics.com&#x2F;ebooks&#x2F;fluid-power-ebook-fluid-power-basics" rel="nofollow">http:&#x2F;&#x2F;hydraulicspneumatics.com&#x2F;ebooks&#x2F;fluid-power-ebook-flu...</a> (and the site also has a &quot;Learning Resources&quot; tab that looks like it will have even more for you when you&#x27;re done with the ebook ;-) ).<p>[1] <a href="https:&#x2F;&#x2F;duckduckgo.com&#x2F;?q=%28pneumatic+OR+air%29+%28logic+OR+memory+OR+circuts%29&amp;t=ffhp" rel="nofollow">https:&#x2F;&#x2F;duckduckgo.com&#x2F;?q=%28pneumatic+OR+air%29+%28logic+OR...</a>