Please fill out the form below for Nrp Valve Butterfl and get a quote for part number 501-1774 PC. NO by Portland Valve Llc with NSN 4820016057624 and FSC Name is 4820 Valves Nonpowered, please include required quantity along with expected turn around time. Our knowledgeable account manager will reply you shortly. Also check for the related parts for part number 501-1774 PC. NO. ASAP Aerospace distributes nose to tail NSN components, sub-assemblies, and assemblies for the aerospace and aviation industry.