Velocity flow control valve for fluid line

摘要

A velocity flow control valve employed in a branch line between a main flow line and pressure responsive pilot valves in a safety system for closing a valve across the main flow line. The flow control valve has interfitting male and female body portions with the male body portion having a spring loaded ball urged upstream to an unseated position and is seated upon a pressure differential to block flow to the pilot valves from the main flow line upon a downstream drop in pressure. A ball bleed valve is positioned on the female body portion upstream of the spring loaded ball and may be opened to reduce fluid pressure between the spring loaded ball and the main flow line when desired.