UNIVERSELLE SICHERHEITSVORRICHTUNG UND VERFAHREN ZUM SCHÜTZEN EINER ROHRLEITUNG

The automatic flow-limiting safety valve comprises a rigid core with an envelope which inflates when excessive flow causes a pressure drop exceeding a specified limit The rigid core (2) is connected to retainers (4a,4b) and also supports an inflatable envelope (5). The lateral wall (503) partially delimits an internal chamber (50). It also faces the internal wall (10) of the pipe (1). The admission valve (3) is calibrated to admit fluid selectively at the upstream end of the chamber, permitting envelope inflation, when the pressure drop exceeds a given threshold. The inflatable envelope blocks the pipe selectively and at least partially, by radial displacement of its sidewall towards the internal wall of the pipe. An Independent claim is included for the method of protecting against excessive flowrate in a pipe, using the unit above. Preferred Features: The core extends along the longitudinal axis (X). The retainers are claws (41-42), each fixed at one end to the core. When folded in, claw tips are close to the longitudinal axis. In the deployed position, the free ends are remote from the axis. Each claw tends to spring outwardly (biting into the pipe). The core has a set transverse diameter (S). The length of each claw exceeds the core radius. The device has an opening (231) in the tubular core wall, and hooked fastenings (611, 621) engaging them and holding the leading and trailing ducts (614, 624) in the body. The body contains a spring-loaded ball, working between these ducts under the action of applied pressure. The claws resemble umbrella spokes, locking the core in the pipe, against movement in opposing directions.