In a preferred embodiment of the invention, an accessory safety valve is provided for mounting within outlet-ports of tanks designed to contain pressurized gas of some sort, particularly of an explosi

A hydraulic valve operating circuit for providing positive opening and closing of a downhole safety valve includes shut-off valves which prevent leakage of fuel to the outside environment if a leak sh

A pressure actuated and resettable safety valve for controlling the flow through a well conduit which closes in response to an increase in pressure in the well conduit. Resetting means for opening the

A wellhead safety valve control system for opening and closing subsurface and surface safety valves in a predetermined sequence and certain components used with such control system. Dump valves in bot

In carrying out the principles of the present invention, in accordance with embodiments thereof, apparatus and methods are provided which solve one or more of the above problems in the art of deep set

A safety valve for installation in a well to close the passage for effluent therefrom comprises a valve body of generally cylindrical shape, shut-off element in a lower part of this body, and a cylind

A blow-down safety valve having means for directing the fluids exiting therefrom along a flow path which assists the valve member to open and seat quickly without excessive bleeding.

A safety valve in combination with a resilient tube for preventing the free flow of fluid through the resilient tube comprises a valve body which is connected to a valve head of generally circular cro