Abstract: The unidirectional limiter comprises a body, each of the ends of which is provided with a connection, a closure member mounted movably between a seat and an abutment element and a throttle ring mounted rotatably on the body of the valve for modifying the section of a throttle passage which is formed in the body and which passes around the valve seat. According to the invention the seat is formed at the end of the internal sleeve member of plastics material, which is latched by axial introduction in the internal bore in the body.

Abstract: An emergency drain device for pneumatic cylinders which is integrated in an orientatable connection fixed directly to the cylinder body and comprises a valve which closes an orifice of the bolt of the connection, going to the atmosphere, when a control pressure is applied to the head of the bolt.This device is advantageously used in installations where a general isolating switch, controlled by the same control pressure, connects the general distribution line to the atmosphere, for example in the case of an emergency, when said pressure disappears.