Abstract: A piloted-safety valve in which a shaft is guided in a guide sleeve in the alve body and both the shaft and the guide sleeve have collars to which ends of an extensible metal jacket are sealingly anchored. The jacket, e.g. a bellows, is in a compressed state when the valve is closed.

Abstract: A flow-control valve has a valve housing defining a chamber formed with ally offset source, sump, and user ports. A valve body in the chamber has first and second coaxial but axially independently movable parts, the first part having a mainly axial throughgoing passage having one end exposed continuously to one of the source and sump ports and an opposite axially open end axially sealingly engageable with the second valve part. A central seat between the source and sump ports is axially sealingly engageable with one of the valve parts to isolate one of the source and sump ports from the other of the source and sump ports.

Abstract: A safety valve for walls and other vessels and adapted to vent the vessel to the atmosphere upon the development of a predetermined maximum pressure in the vessel comprises a step plunger carrying a valve member and adapted to displace the valve member toward and away from a seat in a valve housing in which a command chamber is defined between an axial guide for the plunger and an end thereof. The command chamber is controlled by the pressure from the pilot device and the blocks surrounding this axial guide and is connected to the plunger so that the sealing is effected by the bellows and the guide does not need to have a sealing capability.