SAFETY VALVE Russian patent published in 2001 - IPC

FIELD: safety devices of pipe-lines. SUBSTANCE: safety valve contains cylindrical housing provided with inlet opening. Working end face of the piston provided with sealing gasket pushes against the housing seat. The piston is an integral part of rod which is coaxial to spring tightening the piston to the to the seat via adjusting nut. The adjusting nut is mounted on the external surface of the housing for movement along the thread. The side surface of the piston is provided with annular groove with a sealing placed inside. Stopper plug provided with axial opening receiving the rod is mounted on the housing on the opposite side to the inlet opening. The piston is provided with radial openings arranged in one plane perpendicular to the rod axis between the annular groove and the working end face of the pinion. The openings are connected with the axial rod opening. A member preventing the piston from rotation is placed on its side surface over the annular groove and on the internal surface of the housing. The external surface of the rod is provided with the thread connected with the axial opening of the plug placed in the bore provided on the housing end face and having support platform. The external surface of the plug is provided with a projection for a key for manual control the valve, the end of the rod is provided with nozzle for discharging. Particular feature of the second modification of the device is that the piston is provided with interconnected axial and radial openings placed in one plane perpendicular to the rod axis. The radial openings are located between the annular groove and the working end face of the piston and are connected to the rod opening. A member preventing the piston from rotation is placed on its side surface over the annular groove and on the internal surface of the housing. Needle and the axial opening of the piston form needle valve. The needle is provided with threaded thickening connected with the external thread of the piston. The thread is provided with longitudinal grooves for flowing the fluid and the end of the rod is provided with nozzle for discharging. EFFECT: enhanced reliability as the result of exceeded fluid pressure, excluded possibility of pipe-line destruction, reduced probability of appearance of air locks, expanded functionality, and reduced size of the device. 6 cl, 4 dwg