NSN 4820-01-118-1987

A valve consisting of a ported, dead weighted, hollow piston which moves vertically across the inlet passage within the valve body. Changes in the pressure controlled position of the piston vary the effective area of the ports exposed to the inlet flow in such a manner as to maintain a constant outlet line pressure. It has no seats or disk. For dead weight loaded pressure regulating valve of seat and disk construction, see also valve, regulating, fluid pressure.