MIL-V-18436F

Abstract

This specification covers bronze, cast-iron, and steel body check valves with regrinding, renewable, or regrinding-renewable disks and seats. <b><u>Intended Use:</u></b> Check valves are intended for use in pipelines to automatically prevent a reversal of flow through the line. Swing check valves offer less resistance to flow than lift checks and are generally used in systems where gate valves are employed. Lift checks are generally used in frequent reversals of direction are encountered and a pressure drop comparable to globe or angle valves is allowable. Ball lift checks are specially suited for viscous fluids. Nonmetallic disks, when rated for media temperatures involved, result in quieter operation, will seat even when the media contains small particulate matter, and provide tighter closure at lower pressures, especially for air and gas service. Tilting disk check valves and spring-loaded check valves are characterized by rapid closure action which tends to minimize flow reversal and resultant hydraulic hammer. Class 125, 150, and 200 bronze-body swing check valves and class 150 and 200 bronze-body horizontal, guided-disk lift check valves with metallic disks should be procured under MSS SP-80 if the regrindable seats covered by this specification are not required. <br>