Pressurised hydraulic fluid circuit rupture protection process - has valve controlled by pressure drop detector automatically closing circuit with temporary pressure applied for start-up phase

摘要

A pump (1) supplies pressured hydraulic fluid to the circuit and to a hydraulic tool (3) via a command valve (6), and a fixed min. pressure is engendered in the circuit by a counter pressure valve (7). A detector (8) measures the circuit pressure and signals that the pressure is greater than the min. and this signal holds the circuit command valve open. - In the start up phase a pressure is temporarily applied to the circuit via a bypass valve (9) and this pressure is independent of the signal action on the command valve.